SAUNDERS’ 
QUESTION COMPENDS. No. 3. 
A N A T 0 M Y. QUESTIONS AND ANSWERS 
ON THE 
ESSENTIALS OF ANATOMY 
PREPARED ESPECIALLY FOR 
STUDENTS OF MEDICINE. 
BY 
CHARLES B. NANCREDE, M.D., 
» * i 
SENIOR SURGEON TO EPISCOPAL HOSPITAL , SURGEON TO JEFFERSON MEDICAL COLLEGE 
HOSPITAL; FORMERLY LECTURER ON OSTEOLOGY, ETC., IN MEDICAL DEPARTMENT 
UNIVERSITY OF PENNSYLVANIA ; LATE PROFESSOR OF GENERAL AND 
ORTHOPEDIC SURGERY IN PHILADELPHIA POLYCLINIC; AND 
LATE LECTURER ON SURGERY IN THE DARTMOUTH 
MEDICAL COLLEGE, ETC. 
WITH 117 ILLUSTRATIONS. 
PHILADELPHIA: 
W. B. SAUNDERS. 
1888. Entered according to Act of Congress in the year 1888, by 
W. B. SAUNDERS, 
In the Office of the Librarian of Congress, at Washington. 
D O R N A N , PRINTER, 
PHILADELPHIA. PREFACE. 
The author has endeavored in this little book to embody 
only those facts which have appeared to him to be really the 
“ essentials of anatomynot that he considers it likely that 
the student will master every minute detail therein contained, 
but he believes that the knowledge gained by a study of this 
work will enable the future practitioner, during the remainder 
of his professional life, to recall such general impressions as 
will render intelligible current medical literature, or even the 
more elaborate monographs, and will at once suggest where to 
consult his anatomical text-books for such terms or facts as 
may have become indistinct through lapse of time. 
While this book cannot replace the larger anatomical works, 
sufficient descriptive matter has been introduced to enable the 
student to refresh his memory of the more numerous facts 
learnt in the lecture and dissecting room, or from his “ Gray” 
or other text-book, differing in this respect from most of the 
works of its class, which arejittle more than a list of names, 
without any distinctive facts connected with them to aid the 
student in the difficult task of acquiring a knowledge of a 
branch of medical study almost solely dependent upon the 
unassisted powers of the memory. 
Conciseness, rather than elegance of diction, has been the aim, 
so that all words such as the articles “ a,” “ an,” “ the,” have 
been omitted, except where absolutely necessary. 
Recognizing that a work of this kind should, as far as pos- 
sible, conform to that text-book most commonly used, the last 
V vi 
PREFACE. 
edition of Gray’s Anatomy has been chosen as the chief 
authority, although free use has been made of the works of 
Quain, Leidy, Bock, Allen, Morris On the Joints, Starr On 
Diseases of Children (dentition), Tomes Dental Anatomy, 
Potter, Frey, Holden, Politzer, H. Thompson, Astley Cooper 
On the Breast, and original work of one of the author’s former 
students. 
The author would here acknowledge his obligations and 
return his thanks to Prof. Joseph Leidy, of the University of 
Pennsylvania, for the kind permission to reproduce numer- 
ous cuts from the first edition of his Anatomy, and to Dr. 
F. M. Varrell for much valuable assistance in the correction 
of proof. 
Charles B. Nancrede. 
Philadelphia, September, 1888. CONTENTS. 
PAGE 
Introduction 17 
Bones of the head 23 
The frontal bone 23 
Parietal bones 25 
Occipital bone 27 
The sphenoid 30 
The temporal bones 34 
Ethmoid bone ......... 38 
Nasal bones 40 
The superior maxillary bones 40 
Lachrymal bones 44 
Malar bones 44 
The palate bones ........ 45 
The inferior turbinated bones 47' 
Vomer 48 
The inferior maxillary bone 49 
The sutures and fontanelles 51 
The cerebral fossae . . . . . . . . 53 
The orbital cavities 55 
The nasal fossae . 58 
Bones of the trunk ........ 61 
The vertebral column 61 
The thorax 64 
Hyoid bone 65 
The sternum 65 
Ribs........... 66 
The pelvic bones 68 
The pelvis . . . . . . . . .73 
Bones of the upper extremity. . . . . .74 
vii viii 
CONTENTS. 
PAGE 
The arm 78 
The forearm 80 
The hand 82 
Lower extremity 85 
The thigh 85 
The patella 87 
The leg 88 
The foot 90 
The articulations 92 
Muscles and fasciae 114 
Muscles of the head 116 
Muscles of the neck 120 
Palatal region 122 
Vertebral region 122 
Muscles of the back 123 
Muscles of the abdomen . . . . . . .129 
Muscles of thorax 132 
Muscles of the forearm 136 
Fasciae of the hand 139 
Muscles of the hand ....... 140 
. Muscles of lower extremity . 141 
Muscles of the leg 147 
Fasciae of foot 149 
Muscles of the foot 150 
Vascular system . 152 
The arteries 157 
The veins 177 
The lymphatics 184 
Nervous system 185 
The spinal cord . . . . . . . 198 
The cranial nerves 200 
The spinal nerves 205 
* Dorsal nerves 208 
The sympathetic nerve 211 
Visceral anatomy 216 
The digestive organs 216 
The teeth 217 CONTENTS. 
ix 
PAGE 
The mouth 220 
The pharynx 224 
The oesophagus 226 
The stomach . . . . . . . • . . 227 
The small intestine 229 
The large intestine 231 
The liver 233 
The pancreas 238 
The ductless glands 239 
The spleen ......... 239 
The thyroid gland 241 
The thymus gland ........ 242 
The suprarenal capsules 242 
The abdominal cavity 243 
The peritoneum 246 
Organs of voice and respiration 249 
The larynx 249 
The trachea and bronchi 254 
The lungs ' . . 256 
The pleurae 259 
The urinary organs 260 
The ureters . 265 
The bladder 266 
The male urethra 269 
Female urethra 271 
The male generative organs 271 
The penis 272 
The testes and their coverings 274 
Female organs of generation 279 
The vagina . 281 
The uterus and its appendages 281 
The mammary glands 286 
The organs of sense 287 
The skin and its appendages 287 
Organs of taste 289 
Organs of smell 290 
The eye 292 X 
CONTENTS. 
PAGE 
Sclerotic and cornea 293 
The humors 300 
Appendages of eye 306 
Tutamina oculi 306 
The ear 309 
The external ear 310 
The middle ear or tympanum . . . . . .311 
The tympanum 313 
The internal ear or labyrinth 318 
Anatomy of inguinal hernia . 325 
Femoral hernia 328 
Perineum and ischio-rectal regions ..... 330 ESSENTIALS OF HUMAN ANATOMY. 
Give the derivation and meaning of the term anatomy. 
From two Greek words, literally meaning dissection, but it is 
used to indicate the study of the physical structure of organized 
bodies. 
How is human anatomy divided ? 
Into two great divisions, viz.: 1. General or descriptive anat- 
omy, which deals with the separate parts of the human body; and 
2. Surgical or regional anatomy, which describes the relations in- 
dividual parts, such as muscles, nerves, arteries, etc., bear to each 
other, in order to enable the surgeon to find or avoid important 
structures when operating. 
What is osteology ? 
A subdivision of general anatomy describing the number, form, 
structure, and uses of the bones. 
What is the chemical composition of osseous tissue (bone)? 
About one-third (33.30) is organic or animal matter, resolvable 
into gelatine after prolonged boiling, with traces of cbrondrigen 
(the proximate principle of cartilage), and two-thirds inorganic, or 
mineral, consisting of calcium phosphate (tribasic) 51.04, calcium 
carbonate 11.30, calcium fluoride 2, magnesium phosphate 1.16, and 
sodium chloride with traces of sodium dioxide 1.20. Either the 
organic or inorganic matter may be removed without affecting the 
form of the bone; the former by exposure to heat with free access 
of air, after which slight force will reduce the bone to powder; the 
latter by steeping in dilute hydrochloric acid, which will render 
a long bone as pliable as a strip of rubber. 18 
ESSENTIALS OF HUMAN ANATOMY. 
Does an increase of the mineral constituents take place in 
old age; rendering the bone3 more brittle than in 
youth ? 
No; although this is the common statement in text-books, for 
while equal bulks of young and old bones do show marked differ- 
ences in the proportion of earthy and animal constituents, equal 
weights do not, so that the elasticity in youth and the brittleness 
in age depend upon the greater sponginess of texture in young 
bones. 
Is bone a homogeneous substance ? 
No; for while the exterior is composed of a compact (hard, ivory) 
layer, the inner portions are formed of spongy or cancellous tissue; 
while the interior of long bones is hollow, forming the medullary 
(marrow) canal. The compact tissue is used upon the exterior or 
in the shaft of long bones where “ cross-strain” is greatest, whereas 
cancellous tissue enables the articular end of the bones to be large, 
for security, yet light, this tissue being capable of bearing enorm- 
ous pressure without yielding, but incapable of bearing much 
“cross-strain.” 
Describe the microscopic structure of bone. 
In transverse section, with a low power, a number of holes will 
be observed, averaging inch in diameter, surrounded with a 
series of tolerably concentric circles, consisting of an interrupted 
series of dark spots. With high powers, the holes, called Haver- 
sian canals for the passage of vessels, are seen to be surrounded by 
a series of concentric lines, termed lamellae, while the dark spots 
reveal themselves as cavities in the bone, called lacunae, intercom- 
municating with each other and the central Haversian canal, by 
means of delicate radiating hollow tubes, called canaliculi: this 
aggregation of structures is called an Haversian system. The 
lacunae contain bone corpuscles, processes of which extend into 
the canaliculi. As each Haversian system communicates by its 
canaliculi with those of its neighbor, the exterior of the bone, all 
portions of its most compact tissue and the medullary canal freely 
intercommunicate and receive nutrient material. As these systems 
are circular they would leave interspaces where not in contact; BONE 
19 
but these gaps are filled up by layers of bone with lamellae and 
canaliculi, these portions being called interstitial lamellae. In addi- 
tion to the concentric lamellae around the Haversian canals, an 
examination of a cross-section of a bone long exposed to atmos- 
pheric influences will show that it is composed of a series of cir- 
cumferential fundamental lamellae running around the whole cir- 
cumference of the hone. 
What is the periosteum? 
It is a fibrous membrane serving as a scaffolding to enable the 
bloodvessels to reach all portions of the exterior of the bone except 
its articular ends and the points of attachment of strong tendons, 
the layer in contact with the bone containing many osteoblasts or 
bone-forming cells upon which the growth in thickness of the bone 
depends. 
What is the endosteum ? 
This term is applied to the delicate connective tissue lining of 
the medullary and cancellous tissues which contains numerous 
bone-forming cells (osteoblasts). 
Describe the medulla or marrow. 
There are two varieties. In adult bones—except the cancellous 
tissue of their articular extremities, that of the vertebral bodies, 
the sternum, ribs, and cranial bones—the marrow is yellow, consist- 
ing almost solely of fat (adipose) tissue (ninety-six per cent.). In 
the other situations just mentioned the marrow is red (fcetal), con- 
tains not more than one per cent, of fat, and numerous oval, many- 
nucleated cells (myeloplaxes). This kind of marrow is that found 
in the foetus and infants. 
Do bones receive blood only from vessels in the periosteum ? 
No, for the medullary tissue of all long bones receives a good- 
sized artery (the nutrient artery), which obliquely penetrates the 
compact tissue, after which it divides into two main branches, one 
ascending the other descending in the medullary canal; the veins 
chiefly emerge through numerous openings near the articular ends 
of the bones. 20 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the process of ossification. 
There are two methods, viz., the membranous and the cartilagin- 
ous. In the former, at the centre of ossification of a parietal bone 
for instance, the bone-forming cells (osteoblasts) arrange themselves 
—about the second month of intrauterine life—along the thick 
bundles of fibrous tissue which radiate from the centre of the 
future bone; by the deposition of lime-salts in these osteoblasts, 
the deposit of bone shoots out in needle-like rays toward the 
circumference. Ossification by cartilage is essentially similar; 
for protection of vital centres, as at the base of the skull, or to 
maintain rigidity of parts and proper tension of muscles, as in the 
extremities, certain bones are laid down in cartilage. Just before 
ossification commences the cartilage cells multiply, arrange them- 
selves in columns—especially at the epiphyseal ends—and the 
intercellular material becomes infiltrated with lime-salts. Now 
ossification proper commences by the ingrowth from the peri- 
osteum of buds of young connective tissue covered with bone-form- 
ing cells, which, after causing absorption of the cartilage, become 
converted into bone. The first bones to ossify are 1, the clavicle; 
2, the inferior maxilla (fifth to seventh foetal week). 
Of how many bones is the adult human skeleton com- 
posed ? 
Two hundred, including the os hyoides, but excluding the teeth, 
Wormian bones, all sesamoid bones, except the patellae, and the 
ossicles of the middle ear. 
Into what classes are bones divided, and give a few 
instances of each ? 
Long bones, as femur, tibia; fiat, as those of the vault of the 
skull, scapula; irregular, as the vertebrae; and short, such as the 
carpal or tarsal bones. 
What are Wormian bones ? 
Irregular fragments, developed from supplementary centres, 
situated at the junction of two or more cranial sutures, where, 
during infancy, a membranous interval existed, viz., a fontanelle. 
From their triangular form they are often called ossa triquetra. 21 
BONE 
What are sesamoid bones ? 
Those developed in the substance of tendons, whereby the mus- 
cles obtain additional leverage—i. e., power; the patellae are, by 
some, classed with these bones. 
Of what parts do long bones consist, and what are their 
uses ? 
Of a shaft (body, diaphysis), two articular extremities, and 
various processes; they are developed in cartilage, from one prin- 
cipal, and one or more additional (epiphyseal) centres of ossifica- 
tion ; they serve as supports and levers for power and progression. 
Where are short bones employed, and why ? 
In the carpus and tarsus, where strength with limited motion Is 
required. They ossify in cartilage. 
Describe the structure and uses of flat bones. 
They consist of two layers of compact tissue with interposed 
cancellous tissue, called diplo'e; they serve to protect important 
viscera, as brain, etc., and afford extended surfaces for origin of 
muscles; for the most part, they ossify in membrane. 
How are bony prominences named ? 
Processes, and are described as articular and non-articular. 
Give the names and characteristics of the chief articular 
processes. 
Head, a convex smooth projection, with a constriction or neck 
beneath; found in freely moving joints. 
Condyles, double projecting processes, may have a constriction 
or neck—i. e., neck of condyle of jaw. 
Trochanters, short projecting levers near articulations to facilitate 
rotation of the bone on its long axis. 
Tuberosities, roughened, broad prominences. 
Tubercles, similar to the above, but small with reference to the 
size of the bone. 
Spines and spinous processes, more or less pointed projections. 
Apophysis, strictly speaking, any bony process which develops 
from the primary centre of ossification, commonly used, however, 22 
ESSENTIALS OF HUMAN ANATOMY 
for any process, even if an epiphysis, after it has coossified with the 
mass of the bone. 
What is a diaphysis ? 
The main portion of a bone (shaft in a long bone, body in an 
irregular one) between the epiphyses. 
What is an epiphysis ? 
A supplementary centre, usually to provide for growth in length, 
developed in cartilage, which remains separated by a layer of epi- 
physeal cartilage until the growth of the bone is completed, when 
it coossifies with the diaphysis, and all further growth ceases. Epi- 
physeal centres appear after birth: they coossify in the inverse 
order of their appearance, except that of the lower end of the 
fibula. This process of coossification commences about puberty, 
and the last to unite are those of the upper end of the tibia and 
the vertebral bodies—as late as twenty-five years. 
Mention some of the non-articular processes, with their 
meaning. 
Azygos, without a fellow; coronoid, or coracoid, like a crow’s 
beak ; mastoid, like a nipple; rostrum, a beak; styloid, pen-like; 
squamous, scaly; vaginal, ensheathing. 
Name some of the articular cavities of bone. 
Cotyloid, when they resemble a deep cup; glenoid, when they 
have a shallow-cup form; trochlear, pulley-like; facet, when 
smooth, like one of the surfaces of a cut gem; sigmoid, when 
curved in two opposite directions. 
What are the principal non-articular cavities called ? 
Fossce, shallow depressions; sinuses, deep cavities, communicating 
with the exterior by small openings; grooves, long narrow depres- 
sions ; fissures, cracks; notches, deficiencies of edges of bones; fora- 
mina, holes through bones for transmission of nerves, etc. THE FRONTAL BONE. 
23 
BONES OF THE HEAD. 
Name the bones composing the head. 
They are twenty-two in number: eight of which (cranial) com- 
pose the brain-case, viz., one frontal, two parietal, two temporal, 
one sphenoid, one occipital, and one ethmoid; fourteen are facial: 
two superior maxillary, two malar, two nasal, two lachrymal, two 
palate, two inferior turbinated, one vomer, and one inferior maxil- 
lary ; the ethmoid also enters largely into the formation of the nasal 
cavities. 
The Frontal Bone. 
Of what parts does this bone consist ? 
Of a vertical and horizontal portion. 
Fig. 1. 
Describe the points on the outer surface of the vertical 
portion. 
On each side of the median line are two frontal eminences1, between 
which are the remains of, or the completely obliterated, inter-frontal 
suture, leaving a slight linear depression, which, above the root of 24 
ESSENTIALS OF HUMAN ANATOMY. 
the nose, terminates in a rounded, projecting nasal eminence. Ex- 
tending outward from this on each side are two curved, rounded 
superciliary ridges7, situated beneath which, between the two tables 
of the skull, lie the frontal sinuses14 (Fig. 2). The junction of the 
vertical and horizontal portions forms on each side a curved margin, 
the supra orbital arch3-*, notched or perforated toward its inner part 
by the supra-orbital notch3, or foramen, transmitting the artery, vein, 
and nerve of the same name. Each orbital margin terminates by 
two stout processes, called internal angular3 and external angular4 
processes. Between the inner proj ects the nasal spine3, in the rough, 
uneven space, called the nasal notch; the margin of the external 
angular process extends upward as a temporal ridge8 (Fig. 1). 
Fia. 2. 
Describe the points on the inner surface. 
In the median line a vertical groove10 (Fig. 2) (for the longitudinal 
sinus) exists, whose edges coalesce below to form the frontal crest11, 
which terminates as a notch, or perhaps complete foramen caecum13, 
which when pervious transmits a small vein. 
Describe the horizontal portion. 
This consists of two orbital plated of a triangular outline, 
separated by a quadrilateral ethmoidal notch (for articulation with PARIETAL BONES. 
25 
that bone). A shallow lachrymal12 depression (for gland) exists at 
the outer part of the orbit, also a smaller one or sometimes a small 
tubercle15 at the anterior inner part for the pulley of the superior 
oblique muscle. Several half cells are seen along the margins 
of the ethmoidal notch, which complete the ethmoidal cells 
when the ethmoid is in position, as well as two grooves, which are 
likewise converted into the anterior and posterior ethmoidal canals, 
the former for the nasal nerve and anterior ethmoidal vessels, the 
latter for the posterior ethmoidal vessels. On each side of the 
nasal spine open the frontal sinusesu (absent in children), a part of 
the nasal cavities, into which they open by the infundibulum. The 
inner surfaces of both vertical and horizontal portions present 
numerous depressions for the convolutions of the brain, and 
branching grooves for the anterior meningeal artery. 
What centres of ossification has this bone ? 
Two, near the orbital arches, in membrane, seventh or eighth 
foetal week. 
With what bones does it articulate ? 
With two parietal, the sphenoid, the ethmoid, two nasal, two 
superior maxillary, two lachrymal, and two malar—twelve in all. 
What muscles arise from it ? 
The corrugator supercilii, orbicularis palpebrarum, and temporal, 
on each side. 
Parietal Bones. 
Describe a parietal bone. 
It is of a quadrilateral form, convex externally, the most promi- 
nent point called the parietal eminence. Its upper serrated border 
forms with its fellow the sagittal suture7; the anterior serrated 
margin articulates with the frontal, forming part of the coronal 
suture?-, its anterior inferior angle7, more prolonged than the 
others, articulates interiorly with the sphenoid (spheno-parietal 
suture); the remainder of the inferior border2, bevel-edged; is 
overlapped by the squamous plate of the temporal (squamo-parietal 
suture); the posterior serrated border4 articulates with the occipital 
(occipito-parietal part of lambdoid suture) ; while the posterior 26 
ESSENTIALS OF HUMAN ANATOMY. 
inferior angle8 joins the mastoid process of the temporal (masto- 
parietal suture). Crossing the middle of the bone, from before 
backward, is a curved line, the temporal ridge\ arid near the poste- 
rior superior angle is often a, parietal foramen6 transmitting a small 
vein to the superior longitudinal sinus (sometimes a small branch 
of the occipital artery). 
Fig. 3. 
Describe the internal surface. 
This is concave, marked with numerous smooth digital depres- 
sions for the brain convolutions, with a shallow half groove1 (Fig. 4) 
along the superior border for the superior longitudinal sinus, and 
Fig. 4. OCCIPITAL BONE. 
27 
several Pacchionian depressions. At the anterior inferior angle a 
deep groove, branching in various directions, sometimes converted 
into a foramen, is found7, for the middle meningeal artery, and at 
the posterior inferior angle a broad well-marked groove8 for part of 
the lateral sinus. 
How is it developed? 
In membrane, from one centre at the eminence appearing at the 
fifth to sixth fcetal'week. 
Give muscular attachments, and articulations. 
Temporal muscle: articulates with five bones, parietal, occipital, 
temporal, frontal, and sphenoid. 
Occipital Bone. 
Of what parts does this hone consist? 
Of a curved plate of trapezoidal form, whose anterior blunted 
angle forms the basilar process1 (Fig. 5), and two lateral jugular pro- 
Fig. 5. 
cesses3, arising opposite the two articular processes called condylesn, 
which lie on either side of a large opening, the foramen magnumi11; 
the long axes of the condyles12 converge toward each other from 
behind forward and inward. 28 
ESSENTIALS OF HUMAN ANATOMY. 
What points should be noted on the external convex sur- 
face ? 
Midway between the summit and margin of the foramen 
magnum the prominent external occipital protuberance'1 for attach- 
ment of the ligamentum nuclue; a median crest8 extending from 
this to the margin of the foramen magnum; a pair of superior 
curved lines6 extending from the protuberance toward the lateral 
angles of the bone; a second pair of parallel inferior curved lined*, 
starting about midway along the crest. 
Describe the condyles. 
They are two kidney-shaped convex articular surfaces on each 
side of the foramen magnum, having on their inner sides a rough 
tubercle for the check ligaments. 
What foramina are situated near them ? 
The anterior condyloid2 (constant) for the hypoglossal nerves, and 
posterior condyloid foramina10 (inconstant) for a small vein. 
Fig. 6. 
Describe the basilar process.' 
A strong quadrilateral plate in front of the foramen magnum 
with a median tubercular ridge-like pharyngeal spine. Its cerebral OCCIPITAL BONE. 
29 
surface is smoothly grooved longitudinally for the medulla oblon- 
gata. At its junction with the jugular processes are the deep 
jugular notches forming part of each jugular foramen (foramen 
lacerum posterius). 
Describe the cerebral surface of the bone. 
It is deeply concave, divided into four fossce1311 by a crucial 
grooved ridge13-1*-1'*, crossing at a prominent internal occipital pro- 
tuberance3', the two lateral and superior grooves lodge, respec- 
tively, between the layers of the tentorium cerebelli and the falx 
cerebri, the lateral, and part of the superior longitudinal sinuses; 
the inferior groove, or internal occipital crest1*, has attached the falx 
cerebelli, and lodges in two grooves, the occipital sinuses. The upper 
surfaces of the jugular processes are deeply groovedx for the lateral 
sinuses. 
What do the upper two fossae lodge? 
The posterior lobes of the cerebrum. 
What do the lower fossae accommodate ? 
The hemispheres of the cerebellum. 
With what bones does it articulate ? 
Two parietal, two temporal, sphenoid, and atlas; six in all. 
What centres of ossification has it ? 
One in membrane, at the occipital protuberance (eighth foetal 
week), one for the basilar, and one for each condyloid portion in 
cartilage (seventh or eighth foetal week) : in four pieces at birth; 
in sixth year forms one bone. 
What muscles are attached to the superior curved line ? 
Occipito-frontal, trapezius, and sterno-cleido-mastoid. 
What muscles are attached between the curved lines ? 
Complexus and splenius capitis. 
What muscles are attached below the inferior curved line? 
Rectus capitis posticus major and minor, obliquus superior. 30 
ESSENTIALS OF HUMAN ANATOMY 
What muscles are attached to the basilar process 1 
The superior constrictor of the pharynx, the rectus capitis 
anticus major and minor. 
What muscle is attached to the jugular process ? 
The rectus capitis lateralis. 
The Sphenoid Bone. 
What are its divisions and where is it situated ? 
A body2, two lesser wings', two greater wings, two pterygoid plates, 
two spinous processes10-11, six clinoid processes, and three minor 
prominences; it is situated at the base of the cranium articulating 
with all the cranial bones, and many of the face. Named from a 
Greek word meaning wedge, in the process of development this is 
its function, serving to enlarge the cranial, nasal, orbital, and oral 
cavities at puberty. 
Describe the body of the sphenoid. 
It is large, cuboidal, hollowed out (in adult) into the sphenoidal 
sinuses20 (Fig. 8). Superiorly, in front, is a sharp projecting ethmoidal 
spine6 for the ethmoid; behind this, a smooth surface with a longi- 
tudinal eminence producing two shallow olfactory grooves on either 
side, bounding which behind is a transverse optic groove? (Fig. 7), 
lodging the commissure of the optic nerves,- terminating in two optic 
foramina12 (Fig. 7) for the optic nerves and ophthalmic arteries. 
Behind the groove is the projecting olivary process3 (Fig. 7) forming 
the anterior boundary of a marked depression, the sella turcica? 
(Fig. 7), lodging the pituitary gland and circular sinus. On each 
side, in front, are two small projecting middle clinoidprocesses, while 
behind is a square-shaped projecting plate terminating at either 
angle by the tubercular posterior clinoid processes, and to them are 
attached portions of the tentorium cerebelli. The sides of this 
bony plate are notched for the sixth pair of nerves, and the superior 
surface, or dorsum? (Fig. 7), with a broad shallow depression, slopes 
obliquely downward and backward, becoming continuous Avith the 
basilar portion of the occipital bone; it supports the pons Yarolii. 
A broad cavernous groove* (Fig. 7) for the carotid artery and cavern- THE SPHENOID BONE. 
31 
ous sinus exists on either side of the body. The posterior1 (Fig. 7) 
rough quadrilateral surface articulates with the basilar portion of 
the occipital bone, coossifying from the eighteenth to twenty-fifth 
year. 
Fig. 7. 
A vertical plate, the rostrum?1-2'2 (Fig. 8), projects from the 
inferior surface of the body forming part of the nasal septum, having 
the irregular openings of the sphenoidal sinuses20 on either side 
(absent in child), which open either into the posterior ethmoidal 
cells or directly into the nasal cavities. Two thin-curved sphenoidal 
turbinated20 bones narrow these orifices to a round opening at their 
upper part; these plates articulate with the palate and ethmoid 
bones. 
The inferior surface presents a continuation of the rostrum for the 
vomer, having on either side a thin plate, the vaginal process22, 
under which slips the alse of the vomer, and the pterygo-palatine 
grooves, which by articulation with the sphenoidal processes of the 
palate bones are converted into the ptery go-palatine canals for the 
arteries and nerves of the same name. 
Describe the greater wings. 
Two strong processes arising from the sides of the body, curving 
upward, outward, and backward. The concave cerebral surface14 of 
each wing forms part of the middle fossae of the skull, presenting a 
circular opening at its antero-internal part, the foramen rotundumu 
for the second branch (sup. maxillary) of the fifth pair of nerves; 
a second larger ovoidal foramen, the foramen ovale15 (Figs. 7 and 8). 32 
ESSENTIALS OP HUMAN ANATOMY. 
transmitting the third (inf. maxillary) division of the same nerve 
(sometimes the small petrosal nerve and small meningeal artery), 
•while piercing the sharp, pointed, posterior extremity of the wing, 
or spinous process, is seen a short canal (sometimes double), Wiq fora- 
men spinosum16 (Fig. 7), for the passage of the middle (great) 
meningeal artery. Occasionally, the foramen Vesalii, a small aper- 
ture to the inner side of the oval foramen, opposite to the root of 
the pterygoid process, transmitting a small vein, is detectable. 
The external surface presents the pterygoid ridge dividing the 
temporal from the zygomatic fossa, and at its posterior part the 
spinous process (Fig. 8), giving origin to the laxator and tensor 
tympani muscle, and the internal lateral ligament of the lower jaw. 
Fig. 8. 
The anterior or orbital surface, smooth, quadrilateral, forming 
part of the outer orbital wall, bounded above by a serrated edge 
for articulation with the frontal, below by a rounded border which 
enters into the formation of the spheno-maxillary fissure, internally 
aiding in the formation of the sphenoidal fissure13, presents a serrated 
articular margin for the malar bone, and has a notch at the upper 
part of the inner border for a branch of the ophthalmic artery, a 
small spine at its lower part, for part of the origin of the external 
rectus muscle, and (at times) one or more external orbital foramina. 
The circumference has been described above. 
Describe the lesser wings. 
These5 (processes of Ingrassias) two thin, triangular processes 
each arise from the upper and lateral parts of the body, project THE SPHENOID BONE. 
33 
transversely outward, to terminate internally in the anterior clinoid 
processx (Fig. 7), externally in a sharp point. By their anterior 
borders they articulate with the orbital plates of the frontal bone, 
while by their posterior free margin they divide the anterior from 
the middle cerebral fossae. Between their roots on each side is the 
optic foramen12 (Fig. 7) for the optic nerve and ophthalmic artery. 
Their inferior surface forms on either side the back part of the 
orbital roof, and the upper boundary of the sphenoidal fissure13 
(Fig. 7), or foramen lacerum anterius, which is bounded internally 
by the sphenoid body, and inferiorly by the orbital margin of the 
greater wing, transmitting the third, fourth, ophthalmic branch of 
the fifth and sixth nerves, with the ophthalmic vein, filaments 
from the cavernous sympathetic plexus, also branches of the 
lachrymal and middle meningeal arteries, with a process of the 
dura mater. 
Describe the pterygoid processes. 
These, consisting of an internal11 and external10 plate separated 
behind by a notch—the pterggoid fossa—descend on each side per- 
pendicularly from the junction of the greater wing with the body. 
At the base df the internal plate is the scaphoid fossa, giving origin 
to the tensor palati muscle, above which is the orifice of the Vidian 
canal17; this plate terminates by a curved hamular process11, around 
which plays the tendon of the tensor palati muscle. The external 
pterygoid plate, forming part of the inner wall of the zygomatic 
fossa, has arising from its inner surface the internal pterygoid, and 
from its outer the external pterygoid muscle. The triangular notch 
below has fitting into it the tuberosity of the palate bone. 
Name the bones with which the sphenoid articulates. 
The other seven cranial bones and five facial, viz., the two palate, 
two malar, and vomer. 
By how many centres of ossification is this bone developed ? 
By fourteen centres: two for the internal pterygoid plates in mem- 
brane, two for the greater wings and external pterygoid plates, two 
for the lesser wings, two for the anterior part of the body, two 
for the sphenoidal turbinated bones, two for the posterior part of 
the body, two for the lingula, i. e., posterior part of the outer 34 
ESSENTIALS OF HUMAN ANATOMY. 
margin of the cavernous groove, appearing from the second foetal 
month to the third year in cartilage. From the tenth to the twelfth 
year the parts are all ossified, except a portion of the sphenoidal 
turbinates, which completely unite by the twentieth year. 
What muscles have their origin from the sphenoid bone ? 
The temporal, external and internal pterygoids, superior pharyn- 
geal constrictor, tensor palati, laxator tympani, levator palpebrae, 
obliquus superior, superior, internal, external, and inferior recti. 
The Temporal Bones. 
Where are they situated ? 
At the sides and base of the skull. 
What parts does each bone present for examination ? 
A squamous (scale-like), a mastoid (nipple-like), and a petrous 
(stony hard) portion. 
Describe the squamous portion. 
The main portion is an irregularly semi-circular, smooth plate,1 
grooved posteriorly for the deep temporal arteries, convex exter- 
nally, concave internally, 
and here grooved for the 
middle meningeal artery, 
with digital depressions for 
the cerebral convolutions. 
Posteriorly, a curved ridge 
(part of temporal) is seen. 
Springing from its lower 
part is the long, twisted, 
arched zygomatic process2, 
arising by three roots, viz., 
a posterior, forming part 
of the temporal ridge, one 
running directly imvard 
in front of the glenoid 
fossa, convex, covered with cartilage, forming the eminentia articu- 
larisrand a middle, the outer margin of the glenoid fossa*, the 
Fig. !). THE TEMPORAL BONES. 
35 
obliquely transverse, ovoidal socket for the condyle of the lower 
jaw, divided into two parts by the Glaserian fissure6 (Fig. 11), 
which transmits the laxator tympani muscle, the tympanic artery, 
and lodges the processus gracilis of the malleus: part of the 
parotid gland occupies that portion posterior to the fissure. Parallel 
to this fissure, in the retiring angle between the squamous and 
petrous portions, is the opening of the canal of Huguier for the 
chorda tympani nerve. At the junction of the articular eminence 
with the zygomatic process is the zygomatic tubercle for the ex- 
ternal lateral ligament of the lower jaw. 
Describe the mastoid portion. 
This projects3, rough, and perforated by numerous foramina (one 
large—the mastoid fora- 
men*—transmits a vein to 
the lateral sinus, and a 
small artery), from the 
postero-inferior portion of 
the bone. The interior 
portion of the bone con- 
tains the mastoid cells, 
lined with mucous mem- 
brane continuous with 
that of the tympanum. 
The conical tip is termed 
the mastoidprocess**, upon 
whose inner- side a deep 
grooved digastric fossa26 
(Fig. 11) exists for the digastric muscle, while parallel, but more 
internal, lies the occipital groove27 (Fig. 11), lodging the artery of 
the same name. A deep, curved groove13 (Fig. 10) exists on the 
inner surface of the mastoid portion for part of the lateral sinus, 
in which can be seen the inner orifice of the mastoid foramen. 
Fig. 10. 
Describe the petrous portion. 
This is a dense, pyramidal mass, wedged in between the sphenoid 
and occipital bones, containing the organs of hearing. Its long 
axis is directed from without inward, forward, and a little down- 36 
ESSENTIALS OF HUMAN ANATOMY. 
ward. Its apex, three surfaces, and three borders must be studied. 
The apexu (Fig. 10) lies in the angle formed by the posterior border 
of the greater sphenoidal wing and the basilar process of the occi- 
pital, forms the posterior and external boundary of the foramen 
lacerum medium, and presents the internal orifice of the carotid 
canal. 
The base, its upper half covered by the squamous and mastoid 
portions, presents the oval, expanded orifice of the meatus audi- 
torius externus8, its upper margin smooth, but surrounded for the 
greater part of its circumference by the rough-edged (for the car- 
tilage of the external ear), curved plate of bone called the auditory 
process8. 
The anterior surface forming the posterior part of the middle 
cerebral fossa, presents an eminence19 (Fig. 10) near the centre indi- 
cating the situation of the vertical semi-circular canal of the ear; 
external to this a depression over the tympanum; a shallow groove 
(sometimes double) leading backward and outward to an oblique 
opening, the hiatus Fallopii20, for the petrosal branch of the Vidian 
nerve; a smaller opening (occasionally seen external to the latter) 
for the smaller petrosal nerve; the termination of the carotid canalu 
near the apex; above this canal a shallow depression for the Gas- 
serian ganglion of the fifth nerve. 
The posterior surface forms the anterior part of the posterior cere- 
bral fossa, presents about its centre the large orifice of the short 
(about four lines) meatus auditorius interims15 directed outward 
(closed at its bottom by a vertical perforated plate), wrhich trans- 
mits the facial and auditory nerves (seventh and eighth pairs 
cranial), the auditory artery, and is lined by the dura mater; 
behind the meatus is a small slit leading to the aquoedudus vesti- 
huli16, transmitting a small artery and vein, and lodging a process 
of the dura mater. 
The inferior (basilar) surface, from apex to base, presents a 
rough quadrilateral surface for the origin of the tensor tvmpani 
and levator palati muscles; the circular orifice of the carotid canal'1'1 
(Fig. 11) ascending vertically, then abruptly passing horizont- 
ally forward and inward for the passage of the internal carotid 
artery with its sympathetic nerve plexus; to the inner side of this 
—a small, triangular opening, the aquoedudus cochlea?1, transmit- THE TEMPORAL BONES. 
37 
ting a vein from the cochlea to the internal jugular; behind these 
openings a deep depression, the jugular fossdli (Fig. 11), which 
lodges the lateral sinus, and, with the jugular notch of the occipital 
hone, forms the foramen lacerurnposterius, transmitting the jugular 
vein and eighth pair of cranial nerves; 
a small foramen for Jacobson’s nerve23 in 
front of the bony ridge separating the 
carotid canal from the jugular fossa; 
on the outer wall of the jugular fossa a 
small foramen for Arnold's nerve25; 
posterior to the jugular fossa, a square- 
shaped, smooth facet (covered in the 
fresh state with cartilage), for articu- 
lation with the jugular process of the 
occipital; a broad, sheath-like, bony 
plate extending from the carotid canal 
to the mastoid process, the vaginal 
process7, which splitting into two lam- 
inae, encloses the base of a long, sharp 
spine, the styloid process10 (Figs. 10 and 
11), from which arise the stylo-pharyngeus, stylo-glossus, and stylo- 
hyoideus muscles, and the stylo hyoid and stylo-maxillary liga- 
ments; between this process and the mastoid, a large orifice, the 
stylo-mastoid26 foramen, for the exit of the facial nerve, and the 
entrance of the stylo-mastoid artery ; and, finally, between the 
vaginal and mastoid processes, the auricular fissure for the exit of 
Arnold’s nerve. 
At the angle formed by the junction of the petrous and 
squamous portions, two canals28 exist, separated by a thin, bony 
septum, the processus cochlearifor mis, the upper lodging the tensor 
tympani muscle, the lower being the bony Eustachian tube2*. 
Fig. 11. 
What additional points of interest do the borders present ? 
The superior is grooved for the superior petrosal sinus, and has 
attached to it the tentorum cerebelli; the posterior has a half-groove 
which, with another on the occipital, accommodates the inferior 
petrosal sinus. 38 
ESSENTIALS OF HUMAN ANATOMY. 
From how many centres is this bone developed ? 
From ten: one for the squamous and zygoma (in membrane), 
four for the petrous, two for the mastoid, two for the styloid, and 
one for the auditory process (all latter in cartilage), from eighth 
foetal week to sixth foetal month—bone coossifies during first year, 
except the styloid process. 
With what bones does each temporal articulate ? 
The occipital, one parietal, sphenoid, one malar, and the inferior 
maxillary. 
What muscular attachments has it ? 
Squamous, the temporal; zygoma, the masseter; the mastoid por- 
tion, the occipito-frontal, sterno-mastoid, splenius capitis, trachelo- 
mastoid, digastricus, and retrahens aurem. Styloid, the stylo- 
pharyngeus, stylo-liyoideus, stylo-glossus. Petrous, the levator 
palati, tensor tympani, tensor palati, and stapedius. 
Ethmoid Bone. 
Of what parts does this bone consist ? 
Of a horizontal cribriform plate* (sieve-like, whence name), of two 
lateral masses10 of cells depending from this on either side, between 
which lies the perpendicular plate2 forming part of the septum of 
the nose; the whole bone is of a cuboidal form. 
Describe the cribriform plate. 
Springing from the upper surface is the crusta galli1 (cocks- 
comb), a vertical plate running from before backward, whose 
anterior border is notched to complete the foramen caecum of the 
frontal bone. Two deep, longitudinal olfactory grooves, for the 
olfactory bulbs, lie on either side, their bottoms perforated by three 
rows of small foramina for filaments of the olfactory nerves, and 
on each side in front is a small slit for the nasal branch of the 
ophthalmic nerve; the crest gives attachment to the falx cerebri. 
Describe the perpendicular plate. 
It is thin, usually deflected to one or other side, forms part of 
the nasal septum, and has upon each side numerous grooves and 
canals to accommodate the olfactory nerve filaments. ETHMOID BONE. 
39 
Of what are the lateral masses formed? 
Of thin-walled cavities, the ethmoidal cells, whose outer limits 
are the vertical orbital4 plates, while their inner walls form part of 
the nasal fossae; above they are grooved 
to form with grooves on the frontal the 
two ethmoidal foramina. The upper 
outer margins of each mass present a 
number of half-cells completely closed in 
when articulated with the ethmoid notch 
of the frontal bone; posteriorly are also 
half-cells completed by the sphenoidal 
turbinated and palate bones; again, in 
front and below, the cells are completed 
by the lachrymal and superior maxillary 
bones; interiorly an irregular hook-like 
plate projects, the unciform process?, which 
closes in the upper part of the orifice of 
the antrum. A narrow oblique fissure, 
the superior nasal meatus, subdivides the 
inner surface, bounded above by the thin- 
curved superior turbinated bone6, below by the convex scroll-like 
middle turbinated bone7; the posterior cells open into the upper 
part of this fissure, the anterior into the frontal sinus above, and 
below by the flexuous infundibulum they communicate with the 
middle nasal meatus, which is bounded above by the middle turbi- 
nated bone. 
Fig. 12. 
How many centres of ossification has this bone ? 
Three; one for each lateral mass (fourth to fifth foetal month), 
one for the perpendicular and cribriform plates in cartilage during 
the first year; the ethmoidal cells, completing the bone, form about 
the fourth or fifth year. 
With how many bones does it articulate? 
Fifteen: the sphenoid, two sphenoidal turbinated, frontal, two 
nasal, two superior maxillary, two lachrymal, two palate, two 
inferior turbinated, and the vomer. 40 
ESSENTIALS OF HUMAN ANATOMY. 
Nasal Bones. 
Describe them. 
They are of oblong form, their outer surfaces concave from above 
downward, convex from side to side, marked by many small arte- 
rial furrows and usually presenting at their centres a single or 
double venous foramen. Their inner surfaces are convex from 
above downward and concave from side to side, traversed longi- 
tudinally by a groove, sometimes a canal, for a branch of the nasal 
nerve which escapes by a notch about the middle of the lower thin 
margin. 
With what bones does each nasal articulate ? 
With the frontal, ethmoid, its fellow nasal, and the superior 
maxillary. It has no muscular attachments. 
How is each developed ? 
From one centre in membrane (eighth foetal week). 
The Superior Maxillary Bones. 
Describe them. 
They each consist of a hollow body and four processes ; together 
they form the whole upper jaw. 
Describe the body. 
It is cuboidal in form and hollowed out into a pyramidal cavity, 
the antrum of Highmore11 (Fig. 14). Of its four surfaces, the ex- 
ternal (facial), directed forward and outward, presents, just above 
the incisor teeth, the incisive (myrtiform) fossa1 (Fig. 13), more ex- 
ternally the larger canine fossa8 (Fig. 13), separated from the former 
by the canine eminence formed by the socket of the canine tooth; 
above this the infra-orbital foramen9 (Fig. 13) giving egress to the 
infra-orbital artery and nerve, and, above all, the margin of the 
orbit. 
The posterior surface is convex, forms part of the zygomatic fossa, 
has about its centre several apertures of the posterior dental canals 
for the dental vessels and nerves ; at its lower part (especially after 
the wisdom tooth is formed) is a rounded eminence, the maxillary THE SUPERIOR MAXILLARY BONES. 
4t 
tuberosity2 (Fig. 13), which articulates by its rough inner surface 
with the tuberosity of the palate bone; and just above the rough 
surface is an oblique groove running down on the inner side, which 
by the apposition of the palate bone forms the posterior palatine 
canalVa (Fig. 14). 
The superior (orbital plate) surface5, thin, smooth, and triangular, 
forms part of the floor of the orbit, articulates internally by an 
irregular margin (from behind forward) with the palate bone, os 
planum of the ethmoid and lachrymal; externally, by its smooth, 
rounded edge, it helps to form the spheno-maxillary fissure (some- 
times articulating in front with the orbital plate of the sphenoid), 
and in front, part of the orbital margin. Commencing at the middle 
of the outer border of this surface is the deep infra-orbital groove5 
(Fig. 13), which in front becomes a canal of the same name, opening 
by the infra-orbital foramen ; a small canal branching from this 
passes into the substance of the anterior wall of the antrum—the 
anterior dental canal; at the inner forepart of this orbital surface 
is a minute depression for the origin of the inferior oblique muscle 
of the eye. 
The internal surface, unequally divided horizontally into two parts 
by the palate process12 (Fig. 14), forms above this, part of the outer 
wall of the nasal fossae; below, a portion of the cavity of the mouth. 
The nasal surface presents a large irregular opening into the an- 
trum, above which are irregular cellular cavities closed in, when 
Fig. 13. 
Fig. 14. 
articulated, by the ethmoid and lachrymal bones. Below the 
opening is the smooth surface forming part of the inferior meatus 42 
ESSENTIALS OF HUMAN ANATOMY. 
of the nose; behind a rough surface15 (Fig. 14) for the palate bone 
with a groove passing from above downward and forward, the 
posterior palatine15 (Fig. 14), which, closed in by the palate bone, 
forms the posterior palatine canal; in front, a deeper vertical 
groove10, which by the apposition of the lachrymal and inferior 
turbinated bones forms the lachrymo-nasal duct-, and still more 
anteriorly the well-marked horizontal, rough-ridged inferior turbi- 
nated crest, for the inferior turbinated bone. 
Describe the antrum of Highmore (maxillary sinus). 
It is triangular, with apex outward formed by the malar process, 
its base the outer nasal wall, and opens, in the fresh state, by a 
small orifice of the size of a probe point into the middle nasal 
meatus. In the non articulated bone there is a large, irregular 
opening, which is narrowed when articulated by portions of the 
palate, ethmoid, and inferior turbinated bones. On its posterior 
walls are the posterior dental canals, while its floor presents several 
conical prominences, produced by the fangs of the first and second 
molar teeth; sometimes the floor is actually perforated. The walls 
are very thin. 
Describe the malar process. 
It is a rough, triangular eminence4, concave on its facial and 
zygomatic surfaces, and roughly serrated above for the malar bone. 
Describe the nasal process. 
This is thick, triangular3, rising upward, inward, and backward, 
with an external concave smooth surface, an internal surface 
articulating with the frontal above, and by a rough surface with 
the ethmoid, below this is the transverse ridge-like superior turbi- 
nated crest for the middle turbinated bone. Next comes a smooth, 
concave surface, part of the middle nasal meatus ; then the inferior 
turbinated crest (see ante), and, most inferior of all, the concavity 
forming part of the inferior nasal meatus. The anterior border is 
thin, serrated for articulation with the nasal bone, and the posterior 
border thick, and grooved for the lachrymal duct, which is directed 
backward and a little outward; where the outer margin of the groove 
joins the orbital surface, is the lachrymal tubercle. THE SUPERIOR MAXILLARY BONES. 
43 
Describe the alveolar process. 
This is thick, spongy, with eight cavities of varying depth, that 
for the canine tooth being deepest, those for the molars widest and 
subdivided. 
Describe the palatine process. 
It is a horizontal plate13 (Fig. 14), thickest in front, forms most 
of the roof of the mouth and floor of the nostril; has an upper and 
lower concave surface. In front, upon the upper surface, is the 
upper orifice of the anterior palatine canal, which conducts to a fossa 
formed between the two bones, transmitting the anterior palatine 
vessels through the foramina of Stenson, the naso-palatine nerves 
passing through the intermaxillary suture by the foramina of 
Scarpa-, upon the under surface is a longitudinal groove (some- 
times a canal), leading from the posterior palatine canal, for the 
posterior palatine vessels and nerve, while in front is seen the lower 
orifice of the anterior palatine fossa (foramen) presenting four 
openings; the inner border is thickened into a ridge on the upper 
surface forming the nasal crest, between which and its fellow fits 
the vomer, and which in front forms the anterior nasal spine. 
How is this bone developed? 
Probably by four centres; one for nasal and facial, one for 
orbital and malar, one for palatal in membrane, and one for incisive 
portion in cartilage at sixth to seventh foetal week. Antrum com- 
mences at the fourth foetal month. 
With what bones does it articulate ? 
Frontal, ethmoid, nasal, malar, lachrymal, inferior turbinated, 
palate, vomer, and the other superior maxillary. 
Give the muscular attachments. 
Orbicularis palpebrarum, obliquus inferior of eye, levator labii 
superioris alteque nasi, levator labii superioris, levator anguli oris, 
compressor nasi, depressor alae nasi, dilator naris posterior, mas- 
seter, buccinator, internal pterygoid, and orbicularis oris. 44 
ESSENTIALS OF HUMAN ANATOMY. 
Lachrymal Bones. 
What is their shape and where are they situated ? 
They are two small bones situated at the front part of the 
inner wall of the orbit, resembling in form, thinness, and size 
a finger-nail, hence called os unguis. The external orbital1 sur- 
face presents a vertical ridge giving origin to the 
tensor tarsi muscle, in front of which is a concave 
longitudinal groove2 forming part of the lachrymal 
duct below, lodging the lachrymal sac above. Below 
is a hook-like process7 articulating with the inferior 
turbinated hone, assisting to form the lachrymal 
canal. A depressed furrow is seen on the nasal sur- 
face corresponding to the ridge externally; the sur- 
face in front forming part of the middle nasal 
meatus, the posterior closing in the anterior ethmoidal cells. 
Fir. 15. 
With what bones does it articulate? 
With the frontal4, ethmoid5, superior maxillary 6, and inferior 
turbinated. 
How is it developed'? 
From one centre in membrane, at the eighth foetal week. 
What muscles arise from it ? 
The tensor tarsi of Horner. 
Malar Bones. 
Describe them. 
Two small quadrangular bones placed at the upper outer part of 
face, forming the prominence of the cheelr, parts of the orbit, 
temporal, and zygomatic fossae. The external surface1 is convex, 
smooth, perforated by one or more malar foramina2, for the passage 
of nerves and vessels; it gives origin to the two zygomatic mus- 
cles. The internal6 concave surface has a rough triangular surface 
for the superior maxillary bone. It has superiorly a thick ser- 
rated-edgedfrontal process3 articulating with the external angular 
process of the frontal bone; a thick, strong plate-like orbital THE PALATE BONES. 
45 
process, projecting backward, smooth and concave above, forming 
part of the floor and outer wall of the orbit, convex below, form- 
ing part of the temporal fossa, and bounding the spheno-maxillary 
fissure in front by its free margin, 
having upon its upper surface the 
orifices of one or more temporo-malar 
canals for filaments of the orbital 
branch of the superior maxillary 
nerve. Externally, projecting back- 
ward is the zygomatic process7 articulat- 
ing with the zygomatic process of the 
temporal bone by a serrated margin. 
The upper border4-5, smooth and 
arched, forms the outer and inferior 
margin of the orbit; the lower borders, 
thick and rough, gives origin to the 
masseter muscle ; the anterior border*, roughly bevelled, articulates 
with the superior maxillary; while the posterior border8, like an 
italic /, is continuous above with the temporal ridge, below with 
the upper border of the zygoma. 
Fig. 16. 
How is it developed ? 
From one centre (some say two), at the eighth foetal week in 
membrane. 
With what bones does it articulate? 
With the frontal, sphenoid, temporal, and superior maxillary. 
What muscles arise from it ? 
The levator labii superioris, zygomaticus major and minor, 
masseter, and temporal. 
The Palate Bones. 
Describe them. 
These two bones, situated at the back part of the nasal fossae, 
assist in the formation of the floor and outer wall of the nose, the 
roof of the mouth, the floor of the orbit, the inner wall of the 46 
ESSENTIALS OF HUMAN ANATOMY. 
antrum, and aid in forming the spheno-maxillary and pterygoid 
fossae. 
Of what parts does each bone consist ? 
Of a vertical plate2, a horizontal plate’, and three processes, the 
pterygoid0, sphenoidal9, and orbital*. 
Describe the points on the vertical plate 
This thin oblong plate, directed upward and a little inward, 
presents internally, at its upper part, the superior turbinated crest'1, 
lower a second ridge, the inferior turbinated 
crest6 for the middle and inferior turbinated 
bones, between which lies the groove for the 
middle nasal meatus, and below the inferior 
crest another groove for the inferior meatus. 
Theposterior border articulates with the ptery- 
goid process of the sphenoid; on its external 
surface is a deep groove forming the posterior 
palatine canal by articulation with the supe- 
rior maxilla, transmitting the vessels and,nerve 
of the same name, while the upper and back 
smooth surface helps to form the inner wall 
of the spheno-maxillary fossa, the anterior smooth small lamina 
springing from the anterior border of the bone opposite the 
inferior turbinated crest—the maxillary process—narrows the orifice 
of the antrum, between which is the rough maxillary surface. 
The posterior surface at the lower portion is pyramidal, forming 
the pterygoid processs, is deeply grooved™, forming part of the 
pterygoid fossa, with a Y-shaped, rough margin for articulation 
with the pterygoid plates. 
The superior border, deeply notched by the spheno-palatine fora- 
men’’ (or notch), forms the triangular hollow orbital process9,, in front, 
articulating anteriorly with the maxilla, posteriorly with the sphe- 
noid (its cells here usually opening into the sphenoidal sinus), in- 
ternally, with the ethmoid, and has a free orbital and zygomatic sur- 
face, the latter opening into the zygomatic fossa, with a rounded 
border forming part of the spheno-maxillary fissure; behind, pro- 
jecting upward and inward is the sphenoidal process9, grooved on its 
Fig. 17. THE INFERIOR TURBINATED BONES 
47 
upper surface by apterygo-palatine groove to help to form the same- 
named canal; articulating here with the sphenoid bone, extern- 
ally and posteriorly with the pterygoid process, and having an in- 
ternal concave surface forming part of the outer wall of the nasal 
fossa. 
Describe the horizontal plate. 
This, completing the nasal floor and hard palate, presents on its 
inferior surface a transverse ridge for the tensor palati aponeurosis; 
a deep groove assisting in the formation of the posterior palatine 
canal11; near this the orifices of several accessory posterior palatine 
canals; an anterior border, serrated and bevelled for the palate pro- 
cess of the superior maxillary; a smooth concave posterior border, 
for the attachment of the soft palate, terminating in the median 
line by a projection, which, with its fellow on the other bone, forms 
the posterior nasal spine5, for the azygos uvulae muscle; and an 
internal thickest border, whose upper edge is raised to form, with 
its fellow, a crest* articulating with the vomer. 
How is this bone developed ? 
By one centre in membrane at the angle of junction of the two 
plates (seventh to eighth foetal week). 
With what bones does it articulate ? 
The sphenoid, ethmoid, superior maxillary, inferior turbinated, 
vomer, and opposite palate. 
Give the muscular attachments. 
Tensor palati, azygos uvulae, internal and external pterygoids, 
and superior constrictor of the pharynx. 
The Inferior Turbinated Bones. 
Describe them. 
They are two thin, scroll-shaped bones, extended horizontally 
along the outer walls of the nasal fossae, just below the orifice of 
the antrum, and are attached to the inferior turbinated crests of 
the superior maxillary1 and palate2 bones, and present three pro- 48 
ESSENTIALS OF HUMAN ANATOMY. 
cesses for study, a lachrymal6, in front of the upper border, forming 
part of the nasal duct by its junction with the lachrymal and 
Fig 18. 
superior maxillary bones; further back, the ethmoidal process6, 
joining the unciform process of the ethmoid ; and from the lower 
border of this process the maxillary process3 projects, curving down- 
ward, and hooking over and narrowing the orifice of the antrum. 
The outer surface (from the median plane of the head) is concave; 
its inner convex, roughened, and grooved for arteries and veins. 
Name the bones with which it articulates, and its method 
of development. 
It articulates with the ethmoid, lachrymal, palate, and superior 
maxillary bones; it is developed by one centre in cartilage (fifth 
foetal month). 
Vomer. 
Describe it. 
It is single, plowshare-shaped, vertically placed posteriorly in 
the nasal fossae (usually deviated to one side), and forms part of 
Fig. 19. 
the nasal septum. Its superior border1 is deeply grooved for the 
rostrum of the sphenoid, with lateral wings (alae), which slip under THE INFERIOR MAXILLARY BONE. 
49 
the vaginal processes of the same bone. The anterior border4 is 
grooved for the vertical plate of the ethmoid and the nasal septal 
cartilage. The inferior boi'der2 is received in the groove formed by 
the nasal crest of the superior maxillary and palate bones. The 
posterior border * is free, concave, thick above and thin below, and 
separates the nasal fossae behind. On each lateral surface is the 
naso-palatine groove6 (sometimes a canal) for the nerve of the same 
name, and also small furrows for the lodgement of bloodvessels. 
Name the bones with which it articulates, and its centres 
of ossification. 
The sphenoid, ethmoid, both superior maxillary, and both palate 
hones. It has but one centre (eighth foetal week in membrane), 
which includes between its two layers the septal cartilage; ossifi- 
cation is not completed until after puberty. 
The Inferior Maxillary Bone. 
Enumerate its general characteristics. 
It consists of a body1, with two rami2, which are surmounted on 
either side by a curved beak-like coronoid process8 in front, and 
an articular condyloid process7 posteriorly, the constricted portion 
beneath which is termed the neck of the condyle ; the depression 
separating these two processes is called the sigmoid notch9, crossed 
by the masseteric vessels and nerve. 
Describe the body of the bone. 
It is horseshoe shaped, and presents the following points for 
examination: the prominent triangular eminence in front, the 
mental process*, extending upward from which is a median vertical 
ridge the symphysis*, marking the junction of the two halves of 
the bone; on either side, just below the roots of the incisor teeth, 
is the incisive fossae, giving origin to the levator menti; and more 
externally, below the root of the second bicuspid tooth, the mental 
foramen6, for the exit of the mental artery and nerve. Extending 
outward from the base of the mental process is a distinct ridge1, the 
external oblique line, continuous posteriorly with the anterior border 
of the ramus; to it are attached anteriorly the depressor labii infe- 
rioris and depressor anguli oris. The lower border4, just in front 50 
ESSENTIALS OF HUMAN ANATOMY. 
of the attachment of the masseter, is grooved for the facial artery. 
The internal surface presents an indistinct linear depression, indi- 
cating the point of j unction of the two halves of the bone, on either 
side of the centre of which are four prominent genial tubercles, dis- 
posed in pairs, sometimes blended into two, or even one irregular 
mass, the upper giving origin 
to the genio-hyo-glossus, the 
lower pair to the genio-hyoid 
muscles. Upon each side of 
these tubercles is the oval 
sublingual fossa for the glands 
similarly named, and beneath 
each a rough depression for the 
origin of the digastric muscle. 
Extending obliquely upward 
and backward from the sub- 
lingual fossa is the internal 
oblique line (mylo-hyoid ridge) for the same named muscle; beneath 
its edge is the oblong submaxillary fossa, for the submaxillary 
gland; above it the alveolar portion pitted with alveoli (sockets) 
for sixteen teeth in adult, ten in child. 
Fig. 20. 
Describe the rami. 
These ascending, flattened, quadrilateral plates present in front 
the curved coronoid process8, giving attachment to the temporal 
muscle; the deep sigmoid notchfl, forming whose posterior boundary 
is the condyloid process' surmounting its narrow neck, in front of 
which is a depression for the tendon of the external pterygoid 
muscle, and externally a small tubercle for the external lateral liga- 
ment. The articular surface is oblong, with its long axis trans- 
versely oblique from behind forward and outward, and is convex 
from behind forward, and from side to side. Upon the inner surface 
of the coronoid process commences a longitudinal ridge, with a 
groove, for the temporal above, the buccinator muscle below. The 
outer surface of the ramus has various ridges for the attachment of 
the masseter muscles; its inner surface presents a central oblique 
aperture, that of the inferior dental canal (communicating with each 
alveolus and terminating at the mental foramen) for the vessels THE SUTURES AND FONTANELLES. 
51 
and nerve ; in front of this opening a prominent ridge, terminating 
behind in a sharp spine for the long internal lateral ligament; 
below the spine the myo-hyloid groove for the same named vessels 
and nerves, and behind the groove a rough surface, for the internal 
pterygoid muscle. 
At the junction of the posterior and inferior margins of the 
ramus is the angle5 marked with rough oblique ridges externally for 
the masseter, internally for the internal pterygoid muscle. 
With what bones does the inferior maxillary articulate ? 
With the two temporals. 
What ossific centres has it ? 
It is the second bone of the skeleton to ossify (clavicle first), and 
is probably developed by only two centres, chiefly in membrane, 
partly in cartilage, one for each lateral half, which coossify about 
the first year. 
Compare the forms of the old and adult jaw. 
In old age the alveolar portion being absorbed, the angle formed 
by the ramus with the body is very obtuse, and the dental canal is 
near the upper surface (important surgically in operating for neu- 
ralgia) ; in adult age the ramus is almost vertical, and the dental 
canal lies about the middle of the bone. 
Give the muscular attachments. 
Fifteen pairs; to the ramus the masseters, temporals, internal 
and external pterygoids ; to the inner surface of the body, the genio- 
hyoglossus, genio-hyoid, mylo-hyoid, digastric, superior pharyngeal 
constrictor; to the outer surface of the body the depressor labii 
inferioris, depressor anguli oris, levator menti, orbicularis oris, 
platysma myoides, and buccinator. 
The Sutures and Fontanelles. 
What is a suture ? 
Rows of interlocking, tooth-like processes, projecting from the 
external table of either bone (the inner tables are merely apposed). 
How many sutures are there ? 
Eighteen. 52 
ESSENTIALS OF HUMAN ANATOMY. 
Name those at the vertex. 
The interparietal (sagittal), the fronto-parietal (coronal), and the 
occipito-parietal (lambdoid). 
Name those at the sides. 
Spheno-parietal, squamo-parietal, and masto-parietal 
Name those at the base. 
One baso-sphenoidal, two petro-occipital, two masto-occipital, 
two petro-sphenoidal, and two squamo-sphenoidal. The points ol 
junction of the sphenoid with the frontal and ethmoid, and the 
frontal with the ethmoid, are not usually described as sutures. 
Which only of the facial sutures has received a name ? 
The transverse, that extending from one external angular process 
of the frontal to the other, joining that bone with the malar, sphe- 
noid, ethmoid, lachrymal, superior maxillary, and nasal bones. 
Why does the skull consist of so many pieces ? 
To admit of continuous growth of the bones at their edges, pari 
passu with the growth of the brain, hence premature coossification 
of all the sutures results in idiocy. Obliteration of the sutures 
occurs at variable periods after maturity. 
What are the fontanelles ? 
They are membranous intervals in the infant’s skull, correspond- 
ing to the junction of the four angles of the parietal with the con- 
tiguous bones. They number six, viz., the anterior, of lozenge- 
shape, at the junction of the sagittal and coronal sutures, usually 
closed not later than the second year ; the posterior, triangular, at 
the junction of the sagittal and lambdoid sutures, closed a few 
months after birth; and the lateral, one at the antero-inferior angle, 
another at the postero-inferior angle of each parietal bone, which 
are closed soon after birth. 
How are these spaces closed ? 
By a gradual extension of the ossifying process, or by the develop- 
ment of additional centres, forming so-called Wormian bones. THE CEREBRAL FOSSAE. 
53 
The Cerebral Fossae. 
Describe the general characteristics of the anterior fossae 
with their foramina a. 
Formed by the orbital plates of the frontal1, the cribriform 
plate of the ethmoid with its spine9, and the lesser wings2 of the 
sphenoid, they are convex on either side and concave in the 
median line. The foramina are one median, the foramen caecum, 
which, if pervious, transmits a vein from the nose to the superior 
longitudinal sinus; two slits 9 on each side of the crista galli for the 
nasal nerves; three rows of olfactory foramina on each side for 
the olfactory filaments; on the outer side of each- olfactory groove, 
the anterior and posterior ethmoidal foramina, the former transmit- 
ting the anterior ethmoidal artery and the nasal nerve, the latter 
the posterior ethmoidal artery and vein. 
Give the boundaries and the foramina of the middle fossaeb. 
In front, they are bounded by the posterior margin of the 
lesser wings of the sphenoid2, the anterior clinoid processes11, and 
anterior margin of the optic groove; behind, 
by the upper borders of the petrous portion5 
of the temporal bones, and basilar suture; 
externally by the squamous plates of the 
temporal4 and anterior inferior angles of 
the parietals7. The foramina are on each 
side, the opticu for tire optic nerve and 
ophthalmic artery. The sphenoidal fissure 
(foramen lacerum anterius), transmitting the 
third, fourth, ophthalmic branch of the 
fifth and the sixth cranial nerves, and fila- 
ments of the sympathetic, the ophthalmic 
vein, branches of the lachrymal and middle 
meningeal arteries with a process of the dura 
mater; immediately behind this, the foramen 
rotundum15, for the superior maxillary divi- 
sion of the fifth cranial nerve; more poste- 
riorly, the foramen ovale16, for the inferior 
maxillary division of the fifth nerve, the 
Fig. 21. 54 
ESSENTIALS OF HUMAN ANATOMY. 
small meningeal artery and the small petrosal nerve; between the 
two, internally, the foramen vesalii (often absent), for a small vein; 
piercing the posterior inferior angle of the greater sphenoidal 
wing, the foramen spinosum11, for the middle meningeal artery, 
meningeal veins, and sympathetic nerve branches from the 
cavernous plexus; on the inner side of the oval foramen the 
foramen lacerum medium18 (filled in below by a plate of cartilage 
in the fresh state), for the internal carotid artery, carotid sympa- 
thetic plexus, large petrosal nerve (Vidian), and a small meningeal 
branch from the ascending pharyngeal artery; on the anterior 
surface of the petrous portion of the temporal, the hiatus Fallopii23, 
and beneath it, a small foramen for the small petrosal nerve. 
What are the posterior fossae6'? 
They are deeply concave, and each is formed by the occipital8, 
petrous5 and mastoid6 portions of the temporal, and the posterior 
inferior angle of the parietal7. 
What foramina and other openings does each present ? 
The meatus auditorius interims19 for the facial and auditory nerves, 
and the auditory artery ; the aqucedudus vestibuli for a small artery 
and vein; the foramen lacerum posterius20 transmitting the glosso- 
pharyngeal, pneumogastrie, and spinal accessory nerves, the 
internal jugular vein, and meningeal branches of the ascending 
pharyngeal and occipital arteries ; the mastoid foramen (often 
absent) for a vein; the posterior condyloid foramen (often absent) 
for a vein of the same name; the anterior condyloid foramen21 for 
the hypoglossal nerve, and a meningeal branch from the ascending 
pharyngeal artery: and separating the two fossa3 in the median 
line, the foramen magnum13, accommodating the medulla oblongata 
and membranes, the spinal accessory nerves and vertebral arteries. 
What additional foramina or openings are found at either 
side of the base ? 
The orifice of the Eustachian tube33 admitting air to the middle 
ear. 
The canal for the tensor tympani muscle33 above the former. THE ORBITAL CAVITIES. 
55 
The posterior orifice of the Vidian canal for Vidian nerve and 
vessels. 
Glaserian fissure15 for processus gracilis of the malleus, the 
laxator tympani muscle, the tympanic artery; 
and close by 
The orifice of the canal of Huguier, trans- 
mitting the chorda tympani nerve. 
The canal for Jacobson’s nerve, the tympanic 
branch of the glosso-pharyngeal. 
The aguceductus cochleae, for a small artery 
and vein running to the cochlea. 
The canal for Arnold’s nerve, the auricular 
branch of the pneumogastric. 
The auricular fissure, for the exit of Arnold’s 
nerve. 
The stylo-mastoid foramen™, for the exit of 
the facial nerve, and the entrance of the stylo- 
mastoid artery. 
The anterior26 and posterior27 foramina of the 
palatal region have already been sufficiently 
described, and this region does not properly 
belong to the base of the skull, while those 
opening externally at the base and upon the 
face have been described sufficiently under the temporal bone, and 
the superior and inferior maxillary bones. 
Fig. 22. 
The Orbital Cavities. 
Describe them. 
They are two quadrilateral pyramidal cavities, with bases out- 
ward, their long axes directed from in front inward and backward, 
in such directions that if prolonged they would meet about the 
sella turcica of the sphenoid. Seven bones contribute to the for- 
mation of each, viz., the frontal12, ethmoid27, sphenoid23, lach- 
rymal24, superior maxillary6, palate25, and malar22; they com- 
municate with the cranial cavity, behind, by the optic foramina18 
and sphenoidal fissures23, with the nasalfossce through the lachrymo- 56 
ESSENTIALS OF HUMAN ANATOMY. 
nasal duct, and below, externally, by the spheno-maxillary fissure26 
with the temporal, zygomatic, and spheno-maxillary fossae. 
Fig. 23 
What bones compose the roof, and what is its form ? 
The orbital plate of the frontal, anteriorly, the lesser sphenoidal 
wing behind; it is concave, and directed downward and forward, 
presenting internally a depression28 for the fibro-cartilaginous 
pulley of the superior oblique muscle of the eye, externally the 
lachrymal fossa12 for the gland. 
Describe the floor, and of what bones formed. 
Nearly flat, formed chiefly by the orbital plate of the superior 
maxillary6, and, to a less extent, by the orbital processes of the 
malar19 and palate bones; it presents, just external to the lachrymal 
canal, a depression for the inferior ocular oblique muscle; exter- 
nally, the malo-maxillary suture; near the middle the infra-orbital 
groove; and posteriorly, the potato maxilla,rg suture. THE ORBITAL CAVITIES. 
57 
Give the bones forming, and the points of interest upon 
the inner wall. 
It is flattened, formed by the nasal process of the superior max- 
illary, the lachrymaln, os planum of the ethmoid27 and sphenoidal 
body. It presents in front the lachrymal groove20, bounded behind 
by the lachrymal crest; further back, respectively, the lachrymo- 
ethmoidal and ethmo-sphenoidal sutures. 
What forms the outer wall ? 
The orbital plate of the malar and the greater wing of the sphe- 
noid, and on it are seen the openings of one or two malar canals19 
and the spheno-malar suture. 
Describe the chief points connected with the superior 
external angle of the orbit. 
Posteriorly, the sphenoidal fissure (foramen lacerum anterius)23 for 
the entrance of the third, fourth, ophthalmic branch of the fifth 
and sixth nerves, and branches of the lachrymal and middle men- 
ingeal arteries, a process of the dura mater, sympathetic nerve 
filaments, and the exit of the ophthalmic vein; also the fronto- 
malar and fronto-sphenouial sutures. 
What points does the superior internal angle present ? 
The suture between the lachrymal, ethmoid, and frontal bones; 
between the junction of the two latter bones, the anterior ethmoidal 
foramen '1 for the anterior ethmoidal artery and nasal nerve, and the 
posterior ethmoidal foramen17 for the posterior ethmoidal artery and 
vein. 
What points does the inferior external angle present ? 
The spheno-maxillary fissure26 transmitting the infra-orbital 
vessels and superior maxillary nerve, the ascending branches from 
the spheno-palatine ganglion, and the orbital branch of the supe- 
rior maxillary nerve. 
How is the inferior internal angle formed ? 
By a suture, the union of the lachrymal and os planum of the 
ethmoid with the superior maxillary and palate bones. 
What foramen does the orbital margin present ? 
The supra-orbital3 at the junction of the inner and middle thirds, 
transmitting the supra-orbital artery, veins, and nerve. 58 
ESSENTIALS OF HUMAN ANATOMY. 
What foramen opens at the apex of the orbit ? 
The optic16, between the two roots of the lesser wing of the 
sphenoid, transmitting the optic nerve and the ophthalmic artery. 
Recapitulate the openings communicating with the orbit. 
The optic18, sphenoidal fissure23 (foramen lacerum anterius), 
spheno-maxillary fissure26, infra - orbital canal4, anterior2 and 
posterior17 ethmoidal foramina, malar foramina19, supraorbital 
foramen, and lachrymal canal20 (occasionally, in addition, one 
or more external orbital foramina). 
The Nasal Fossae. 
Describe them. 
They are two irregular cavities, extending from the base of the 
cranium above to the roof of the mouth below 17, separated in the 
median line by a thin osteo-cartilaginous septum, opening upon 
their facial aspect by two large apertures, the anterior nares*-10, 
and into the pharynx by the posterior nares15. Each fossa com- 
municates with four sinuses and four cavities. 
Of what parts is the nasal septum composed ? 
In front, the crest of the nasal bones, and the frontal nasal spine; 
its middle portion, the vertical plate of the ethmoid; behind, the 
rostrum of the sphenoid and the vomer; below, the crests of the 
superior maxillary and palate bones. 
What points does the roof of each fossa present 1 
In front, the slit for the nasal nerve; numerous foramince for 
the olfactory filaments; most posteriorly the opening of the sphe- 
noidal sinus'24. 
The floor ? 
In front, the anterior nasal spine10; behind this the upper open- 
ing of the anterior palatine canalu; internally the nasal crest1'2-17 
of the superior maxillary and palate bones. 
Describe the chief points of interest in the outer wall of 
each fossa. 
This presents three irregular longitudinal passages, formed by THE NASAL FOSSAE. 
59 
three projecting bony plates, called the superior19, middle20, and 
inferior meatuses21. 
Describe each meatus. 
The superior19 occupies the posterior third of the wall, lies be- 
tween the superior6 and middle7 turbinated hones (processes of the 
ethmoid), and has opening into it two foramina, the spheno-pala- 
tiner° posteriorly, the posterior ethmoidal cells in front part of the 
upper wall. 
Fig. 24. 
The middle20 occupies the posterior two-thirds of this wall, lies 
between the middle and inferior turbinated bones, and has opening 
into it, in front, the infundibulum; in its centre, the antrum™. 
The inferior21 lies between the inferior turbinated bone and the 
nasal floor, extends along the whole length of the outer wall, and 
has opening into it, in front, the lower orifice of the lachrymo- 
nasal duct (and the anterior palatine canal in the macerated bone, 
not in the natural state). 
Describe the position and boundaries of the temporal fossa. 
Situated at the lateral region of the skull, each fossa is marked 
out upon the skull-cap by the temporal ridge, which extends in a 
curved line first upward and backward from the external angular 
process of the frontal bone, then downward behind to form the 60 
ESSENTIALS OF HUMAN ANATOMY. 
posterior root of the zygomatic process. Its anterior boundaries 
are the frontal, malar, and greater wing of the sphenoid, above and 
behind the temporal ridge, below the pterygoid ridge on the greater 
wing of the sphenoid, externally the zygomatic arch; it opens 
below into the zygomatic fossa, and is filled by the temporal 
muscle, and is traversed by grooves, for branches of the deep 
temporal artery. 
Describe the zygomatic fossa, its boundaries, and commu- 
nicating fissures. 
It is bounded, anteriorly, by the tuberosity of the superior max- 
illa, and the ridge descending from its malar process ; superiorly, 
by the pterygoid ridge of the greater sphenoidal wing and squamous 
plate of the temporal; behind, by the posterior border of the ptery- 
goid process ; below, by the alveolar border of the superior maxilla; 
internally, by the external pterygoid plate ; and externally, by the 
ramus of the lower jaw and the zygoma. The spheno-maxillary and 
pterygo-maxillary fissures open into its inner upper part. 
What does it lodge ? 
The internal and external pterygoid and part of the temporal 
muscle, the internal maxillary artery and inferior maxillary nerve 
and their branches. 
Describe the spheno-maxillary fissure. 
It runs horizontally, opens into the outer back part of the orbit, 
lying between the lower orbital border of the greater wing of the 
sphenoid and the outer border of the orbital plate of the superior 
maxillary and a small part of the palate bone; externally is a small 
part of the malar, while, internally, it joins the pterygo-maxillary 
fissure at a right angle; it transmits the infra-orbital artery, the 
superior maxillary nerve, with its orbital branch, ascending 
branches from Meckel’s ganglion, and serves to connect the orbit 
with the spheno-maxillary, temporal, and zygomatic fossae. 
What are the boundaries of the pterygo-maxillary fissure, 
and what passes through it ? 
It is bounded, in front, by the maxillary tuberosity; behind, by 
the pterygoid plate of the sphenoid; descends at right angles from THE VERTEBRAL COLUMN. 
61 
the inner extremity of the spheno-maxillary fissure, transmits 
branches of the internal maxillary artery, and connects the zygo- 
matic and spheno-maxillary fossae. 
Describe the spheno-maxillary fossa. 
Situated at the junction of the spheno-maxillary and pterygo- 
maxillary fissures, it is bounded, above, by the under surface of 
the body of the sphenoid, and by the orbital process of the palate; 
in front, by the superior maxillary bone; behind, by the pterygoid 
process of the sphenoid ; internally, by the vertical plate of the 
palate. In this fossa terminate the sphenoidal, spheno-maxillary, 
and pterygo-maxillary fissures. The orbital, nasal, and zygomatic 
fossae communicate with it, and also the cranial cavity. 
How many foramina open into it? 
Five (sometimes seven or eight); three in the back wall, viz., 
above, the foramen rotundum; more internal and inferior, the 
Vidian; and lowest and most internal, the pterygo-palatine \ on 
the inner wall is seen the spheno-palatine foramen ; below, the upper 
orifice of the posterior palatine canal, and sometimes two or three 
accessory posterior palatine canals. 
BONES OF THE TRUNK. 
The Vertebral Column. 
How are the vertebrae divided ? 
By regions, viz., into cervical (7); dorsal (12); lumbar (5); sacral 
(5); and coccygeal (4); 33 in all. 
What are the sacral and coccygeal vertebrae called to dis- 
tinguish them from the remaining bones ? 
False, the others being called true (false described with pelvic 
bones). 
What parts are common to all vertebrae ? 
A body1-, posteriorly on each side a pedicle2, supporting two 
lamina;3, which, joining behind enclose the ■spinal foramen*; from 62 
ESSENTIALS OF HUMAN ANATOMY. 
the junction projects a spinous process5: from other parts six 
additional processes arise, viz., two transverse6, and four articular7 7/. 
Describe a vertebral body.. 
Composed of cancellous bone, with a thin, compact layer exter- 
nally, its sides are concave from above downward, while its upper 
surface is, in the cervical region, concave laterally, forming a lip at 
either side, while the lower surface is convex from side to side, and 
concave from before backward, forming an anterior lip; in the 
dorsal region it is flat above and below; and in the lumbar region, 
flattened, or slightly concave above and below. Articular facets 
and demi-facets for the heads of the ribs, mark the dorsal bodies, 
neither the lumbar nor the cervical bodies having these. 
Describe the pedicles. 
They project backward in all but the cervical vertebrae, where 
they are directed obliquely outward. They present intervertebral 
notches above and below (deepest above in the cervical vertebrae; 
below in the dorsal and lumbar spine), forming, when articulated, 
intervertebral foramince for the exit of the spinal nerves, and the 
entrance of vessels. 
Fig. 25. 
What are the laminae ? 
Two broad plates closing in the spinal foramen, roughened at 
their upper margins and their inferior internal surfaces for the 
ligamenta subflava. THE VERTEBRAL COLUMN. 
63 
Describe the transverse processes 
They are bifid in the cervical and perforated by the vertebral 
foramen for the vertebral vessels; thick, strong, and long, with 
anterior articular facets, in the dorsal; long and slender in the 
lumbar: they spring from the junction of the pedicle and lamina, 
and also from the side of the body in the cervical region. 
Describe the articular processes. 
Two are superior and two inferior, projecting from the junction 
of the laminse and pedicles. The upper pair look upward and 
backward in the cervical region; backward and outward in the 
dorsal, inward and slightly backward in the lumbar; the lower 
pair are exactly the reverse of the upper in each region. 
Describe the spinous processes. 
Bifid, short, and horizontal in the cervical; long, triangular, 
directed obliquely downward in the dorsal; and thick, broad, 
quadrilateral in the lumbar. 
Describe the spinal foramen. 
It is largest and triangular in the cervical, smallest and round in 
the dorsal, medium and triangular in the lumbar. 
Name the peculiar vertebrae of each region, and describe 
them. 
The first cervical, or atlas; the second cervical, or axis; the 
seventh cervical, or vertebra prominens; the first, ninth, tenth, 
eleventh, and twelfth dorsal, and the fifth lumbar. 
The atlas supports the head, and is formed of two lateral masses 
joined by an anterior and posterior arch; the former presents a 
facet, posteriorly for the odontoid process. Upon the upper surface 
of each lateral mass is an articular facet, looking upward, inward, 
and backward for the occipital condyles, while the inferior facet 
looks downward and directly inward; a small tubercle represents 
the spinous process. Development is by one centre for anterior 
arch (first year); one for each lateral mass (sixth fcetal week). 
The axis has surmounting the body the odontoid process, with a 
facet in front for articulation with atlas, another behind for the 
transverse ligament, with a roughened apex, to which are attached  ESSENTIALS OF HUMAN ANATOMY. 
the check ligaments; on each side of the odontoid, facing upward 
and-outward, are the superior articulating processes. Development 
is like other vertebrae, except three additional centres for odontoid, 
two appearing at the sixth foetal month. 
The vertebra prominent is so called because of its long, spinous 
process, to which is attached the ligamentum nuclne. Develop- 
ment, like other vertebrae, except one additional centre for anterior 
part of transverse process. 
The dorsal vertebrae. 
The first has an entire facet and a demi-facet on body; the 
ninth has a demi-facet on body above, and a facet on the trans- 
verse process; the tenth has one facet on the body and one on 
the transverse process; the eleventh and twelfth, one facet on the 
body, none on the transverse processes, the latter also closely 
resembling those of a lumbar vertebra. 
The fifth lumbar has a markedly wedge-shaped body, with the 
base forward. 
How are the ordinary vertebrae developed ? 
By one centre for the body, one for each lamina (sixth to eighth 
foetal week); at sixteen years, one centre for the tip of each trans- 
verse, and two for the spinous process ; and at twenty-one years, a 
plate upon the upper and lower surface of the body; the lumbar 
vertebrae have two additional centres tipping the superior articular 
processes; coossification at thirty years. 
The Thorax. 
Give its structure, form, and boundaries. 
It is conical in form, and its osseo-cartilaginous framework is 
formed by the dorsal vertebral bodies behind, the ribs laterally, 
and the costal cartilages and sternum in front; its base is formed 
by the diaphragm. Through its apex, the great cervical vessels, 
the pneumogastric, phrenic, and sympathetic nerves, the trachea, 
oesophagus, and thoracic duct pass (it is also said, the apices of 
the lungs during inspiration). HYOID BONE—THE STERNUM 
65 
What are the most important structures this cavity con- 
tains ? 
The trachea, primitive bronchi and lungs, the heart, aorta and 
its primary branches, the internal mammary arteries, the venae 
cavse, bronchial and azygos veins, the pneumogastric, phrenic, and 
splanchnic nerves, the oesophagus, thoracic duct, lymphatic vessels 
and glands. 
Hyoid Bone 
Describe this bone and its development. 
It consists of a body and two greater and two lesser cornua; the 
greater cornua project backward from the lateral surfaces of the 
body, and have attached to their tubercular ends the thyro-hyoid 
ligaments; the lesser cornua, attached to the junction between the 
body and greater cornua, give attachment, by their apices, to the 
stylo-hyoid ligaments; it is developed by five centres: one for 
body, and one for each greater horn toward the end of foetal life; 
one for each lesser horn some months after birth. 
Give the muscular attachments. 
The sterno-hyoid, thyro-hyoid, omo-hyoid, digastric, stylo-hyoid, 
inylo-hyoid, genio-hyoid, genio-hyo-glossus, hyo-glossus, middle 
pharyngeal constrictor, and sometimes the lingualis. 
The Sternum. 
Describe it. 
The breast-bone consists of three segments, viz., the manubrium 
(handle), the gladiolus (sword), and the ensiform (xiphoid) car- 
tilage. Upon the upper border of the manubrium8 is the inter- 
clavicular notch11; upon either side of which is the facet12 for the 
clavicle; lower, another for the first rib; below, a demi-facet'1 for 
the second rib. 
The gladiolus9 has a demi-facet7 above for the second rib, another 
below for the seventh7, and, between, facets 3,4,5, 6, for the third 
fourth, fifth, and sixth ribs. 
The ensiform cartilage10 has a demi-facet7 above for the cartilage 
of the seventh rib. 66 
ESSENTIALS OF HUMAN ANATOMY. 
How is this bone developed ? 
By six centres; one for manubrium, tour for gladiolus, one for 
ensiform cartilage (fifth foetal month to eighteen years); the three 
pieces rarely coossify. 
26. 
What muscles are attached to this bone ? 
Above, the sterno-cleido-mastoid, the sterno-hyoid, and sterno- 
thyroid ; below, the rectus abdominis, external and internal 
oblique, transversalis, and diaphragm; in front, the pectoralis 
major; behind, the triangularis sterni. 
Ribs. 
What is their number, and how are they divided ? 
Twelve on each side, seven of which are true, or those articu- 
lating with the sternum by a separate cartilage; five false, three 
of which indirectly articulate through the medium of the seventh 
cartilage; while the two lowest, having their anterior extremities 
free, are called floating ribs. RIBS. 
67 
Of what parts does a rib consist ? 
A head, neck, shaft, angle, and tuberosity, except the eleventh 
and twelfth ribs. 
Describe these parts. 
The head1 (except first, tenth, eleventh, and twelfth ribs having 
only one facet) is divided into two facets by a ridge for the inter- 
articular ligament. The neck2 is flattened, roughened upon its upper 
border for the anterior, and upon its posterior surface for middle 
costo-transverse ligaments; in front it is smooth. The tuberosity3 
(absent in eleventh and twelfth), placed at the base of the neck, 
presents a facet for the transverse process of the next lower ver- 
tebra, and a rough surface for the posterior costo-transverse liga- 
ment. The shaft5 is twisted on its long axis (except first and 
second), externally convex, its upper border rounded, its lower 
grooved4 for the intercostal vessels and nerve, and presents at its 
anterior extremity an oval depression6 for the costal cartilage. The 
angle*, at a variable distance in front of the tuberosity, is indicated 
by a rough line. 
How are the ribs developed ? 
By three centres (except eleventh and twelfth, two centres), one 
each for head, shaft, and tuberosity (for shaft sixth foetal week) ; 
for head and tuberosity (sixteen to twenty years); coossifies at 
twenty-fifth year. 68 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the peculiar ribs. 
They are the first, second, tenth, eleventh, and twelfth ribs. 
First rib c, broad, short, fiat, one facet on head, angle absent; on 
upper surface two parallel grooves, the anterior for the subclavian 
vein, the posterior for the artery, and between them a tubercle7 for 
the anterior scalene muscle a sure guide to the subclavian artery. 
Second rib, also flattened, the tuberosity and angle nearly coin- 
cide, and presents near its middle a rough eminence, for the attach- 
ment of part of the first, and all of the second digitation of the 
serratus magnus. 
Tenth rib d, one facet on head. 
Eleventh rib, one facet on head, no tuberosity, no neck, slight 
angle. 
Twelfth rib, one facet on head, neither neck, angle, nor tuberosity. 
The Pelvic Bones. 
What are they ? 
The ossa innominata, the sacrum, and the coccyx. 
Describe the innominate bones. 
They are formed by the union, about puberty, of three bones, 
the ilium1, ischium2, and pubes.3 At their point of junction is the 
acetabulum19 (cotyloid cavity) for the head of the femur—the 
pubes forming one-fifth, the ilium and ischium each about two- 
fifths. A rough central depression at the bottom of the acetabulum 
lodges a vascular mass of fat covered with synovial membrane, 
while the anterior lower margin is interrupted by the cotyloid notch, 
bridged across by the transverse ligament, beneath which passes 
the nutrient vessels and ligamentum teres, which latter arises 
from either side of the notch externally; the whole margin has 
attached to it the cotyloid ligament. Between the pubes and 
ischium, on the anterior surface, is the obturator foramen20 (thy- 
roid), closed by the membrane of the same name, except above 
externally where the obturator vessels and nerve escape; the fora- 
men is a large ovoidal opening in the male, a smaller and triangular 
one in the female. THE PELVIC BONES. 
69 
Describe the ilium. 
This is the upper expanded portion of the bone, presenting 
along its upper border the crest4 with its outer and inner lips, 
terminating in front by the anterior superior spinous process8, giv. 
ing origin to Poupart’s ligament, the sartorius and tensor vaginse 
femoris muscles, and behind by thq posterior superior spinous pro- 
cess10, to which are attached part of the erector spinae muscle and 
the oblique band of the sacro-iliac ligament. Below both the 
anterior8 and posterior spines10 is a process called, respectively, 
the anterior9 (for straight tendon of the rectus femoris muscle) 
and posterior inferior spinous11 (for great sacro-sciatic ligament); by 
these projections a notch is formed in front and behind, the former 
giving partial origin to the sartorius muscle and transmitting the 
Fig. 28. 
Fig. 29. 
external cutaneous nerve. Between the posterior inferior spine 
and the spinous process of the ischium is situated the greater 
sacro-sciatic notch13, giving egress to the pyriformis muscle, the 
greater and lesser sciatic, superior gluteal and pudic nerves, 
also one to the obturator externus muscle, and the sciatic, gluteal 
and pudic vessels. About two inches from the posterior superior 70 
ESSENTIALS OF HUMAN ANATOMY. 
spine, passing downward and outward from the crest, is the supe- 
rior curved line1, from the surface back of which arise the gluteus 
maximus muscles and a few fibres of the pyriformis; about an 
inch behind the anterior superior spine, passing from the crest 
downward and backward to the upper part of the great sacro- 
sciatic notch, is the middle curved line3, the gluteus medius arising 
from the space between these two lines ; passing downward and 
backward, from the upper part of the anterior inferior spine to the 
front of the sacro-sciatic notch, is the inferior curved line3, between 
which and the middle arises the gluteus minimus. Above the ace- 
tabulum is a groove for the reflected tendon of the rectus femoris 
muscle. The inner surface presents the large, smooth concave 
Venter (internal iliac fossa)1 (Fig. 29), limited below by the promi- 
nent ilio-pectineal line, and behind the iliac fossa is the rough auricu- 
lar surface9, the lower part for articulation with the sacrum, the 
upper for the posterior sacro-iliac ligaments. 
Describe the ischium. 
It consists of a body, tuberosity, and ramus, and forms the lowest 
part of the innominate bone. The external surface of the body2 forms 
two-fifths of the acetabulum; below this is a groove for the obturator 
exter’nus tendon; its inner surface forms the lateral boundary of the 
true pelvis; from the posterior border, below the centre, projects the 
spine of the ischium19 (Fig. 29), above and below which are the 
greater22 and lesser sacro-sciatic notches13, the latter giving egress to 
the obturator externus muscle and its nerve, and ingress to the 
pudic vessels and nerve. The lowest portion presents a tuberosity18, 
with an outer and inner lip—to the latter being attached the 
greater sacro-sciatic ligament; above is a groove for lodgement of 
the internal pudic vessels and nerve. Passing upward and inward 
from the tuberosity to join the ramus of the pubes, and bounding 
the obturator foramen in front, is the thin, flattened ascending 
ramus17. 
Describe the pubes. 
This bone (also called pectineal) consists of a body2 or hori- 
zontal12 and a descending (perpendicular) ramus13. The outer end 
forms one-fifth of the acetabulum; above, a rough ilio-pectineal THE PELVIC BONES. 
71 
eminence indicates the point of junction with the ilium; the inner 
end is the oval symphysis11 with eight or nine ridges for attachment 
of the fibro-cartilage; the upper triangular surface presents pos- 
teriorly the pectineal portion of the ilio-pectineal line16; the ante- 
rior surface presents the crest}1, ending externally in the pubic 
spine15 giving attachment to Poupart’s ligament, internally in the 
angle; below is a groove for the obturator vessels and nerve ; the 
descending ramus1'1, thin and flat, joins that of the ischium, com- 
pleting the anterior boundary of the obturator foramen. 
How are these bones developed ? 
By three primary centres, one for each bone (from the eighth 
foetal week to fifth foetal month); and one for the crest, one for 
the tuberosity, one for the anterior inferior spine, one for sym- 
physis, and one Y-shaped, joining the three pieces forming the 
acetabulum, appearing about puberty; bone coossifies completely 
about twenty-fifth year. (For order of junction, see Gray.) 
What muscular attachments has the innominate bone ? 
Those of the abdomen, some of the thigh, those of the peri- 
neum, pelvic floor and rotators of the thigh. 
Describe the sacrum. 
It id composed of five consolidated vertebrae, is of triangular 
form with broad base and blunted apex and lateral expanded 
masses or alee; its anterior surface is concave, its posterior convex, 
and with the coccyx it forms the posterior wall of the true pelvis. 
Its anterior surface is marked by four transverse ridges1, indicating 
the lines of junction of the segments; eight anterior sacral fora- 
mina1 with broad shallow grooves for the anterior sacral nerves 
open on this surface; the point of junction with the last lumbar 
vertebra forms the promontory (sacro-vertebral angle); and upon 
each side are the alee1—the expanded portions of the bone. Pos- 
teriorly are three or four median tubercles (rudimentary spinous 
processes); externally are the laminae, those of the fifth and 
sometimes the fourth being deficient; outside these is a row of 
rudimentary articular processes. On each side of the spine is a 
broad sacral groove, lodging the origin of the erector spinse 
muscle; externally are the four posterior sacral foramina on each 72 
ESSENTIALS OF HUMAN ANATOMY. 
side; at the posterior inferior portion of the bone are the two 
cornua—articulating surfaces for the coccyx; each lateral surface 
Fig. 30. 
Fig. 31. 
has on its anterior upper part an auricular surface4 for articulation 
with the ilium; on each side of the apex below is a deep notch™ n, 
for the fifth sacral nerve; the base6 resembles the upper surface 
of a lumbar vertebra, with the last of which it articulates; the 
apex9, directed downward and forward, has an oval concave 
articular surface for the coccyx; the sacral canal runs the whole 
length of the bone, triangular above, small and flattened below, 
and deficient in its posterior wall at the lower part; it lodges the 
sacral nerves, and into it open the anterior and posterior sacral 
foramina. 
What centres of ossification has the sacrum ? 
Thirty-five, appearing from the eighth foetal week to the twen- 
tieth year, coossification being complete from the twenty-fifth to 
thirtieth year. The bodies have each three centres; each lamina 
one centre; the lateral masses three centres each; the lateral 
surfaces two each. 
Give the muscular attachments 
The pyriformis, coccygeus and iliacus in front, the gluteus 
maximus, latissimus dorsi, multifidus spinae, erector spinae, and 
sometimes the extensor coccygis behind. 
Describe the coccyx. 
Usually composed of four rudimentary vertebrae, more or less 
coossified, it forms a triangular bone whose base1 articulates with THE PELVIS. 
73 
the sacral apex. The first piece presents two cornua1, projecting 
upward from either side of the base for articulation with the 
sacral cornua, their junction completing the fifth sacral foramina 
for the posterior branches of the fifth nerves. The apex6 is rounded 
and occasionally bifid or turned to one side; two rudimentary 
transverse processes3 are seen on the first piece.^ 
Describe its development. 
From four centres: one for each segment, the first piece com- 
mencing at birth; second, five to ten years; third, ten to fifteen 
years; fourth, fifteen to twenty years; coossification varies as 
to time and manner. 
Give the muscular attachments. 
Laterally the coccygei; behind the gluteus maximus and ex- 
tensor coccygeus (when present); apex, sphincter ani; in front 
levator ani. 
The Pelvis. 
Describe the pelvis. 
Formed by the two innominate bones, the sacrum and the 
coccyx, all above the ilio-pectineal line is called the false pelvis, 
consisting of the two iliac fossae; all below, the true pelvis. 
Describe the true pelvis. 
Its brim, or inlet, somewhat heart-shaped, is formed oy the linea 
ilio-pectinea at the sides, completed in front by the spine and 74 
ESSENTIALS OF HUMAN ANATOMY. 
crest of the pubes, behind by the anterior margin of the base of 
the sacrum and promontory of the sacrum. Its average diameters 
in the female are, four and one-half inches; trans- 
five and a quarter inches; the oblique"6, five inches; its long 
axis, if extended, would pass from the middle of the coccyx to the 
umbilicus; in the male these measurements are diminished by at 
least one-half inch. 
Describe the cavity. 
This is bounded in front by the symphysis pubis, behind by the 
concavity of the sacrum and coccyx, on either side by the broad, 
smooth, quadrangular inner surface of the body of the ischium, 
forming a curved canal wider in the middle than at its outlets, 
measuring in depth at the symphysis one and one-half inches, three 
and one-half inches in the middle axial line, and four and one- 
half inches posteriorly, perhaps as much as five and one-half 
inches in males. 
Describe the lower circumference of the pelvis. 
This is called the outlet, is bounded on each side by the tuberosi- 
ties of the ischium, the pubic arch in front and tip of the coccyx 
behind. Its diameters are four and one-quarter to four and three- 
quarters inches transverse, antero-posterior and oblique four and 
one-half increased to five by pressure on the coccyx; in the male, 
the diameters average three and one-half inches. 
What are the chief differences between the male and 
female pelves ? 
The strength of the bones, distinctness of the muscular impres- 
sions, the depth and narrowness of the cavity, and large obturator 
foramina mark the male pelvis-, the lighter bones, broader iliac 
fossae, the less-curved sacrum, the wider pubic arch, and the uni- 
versally greater diameters, distinguish the female pelvis. 
Bones of the Upper Extremity. 
Name the bones. 
The clavicle, scapula, humerus, radius, ulna, scaphoid, semi- 
lunar, cuneiform, pisiform, trapezium, trapezoid, os magnum, unci- 
form, five metacarpal, and fourteen phalangeal bones. BONES OF THE UPPER EXTREMITY. 
75 
Describe the clavicle. 
It is a long bone, curved like the italic letter /, its outer third 
flattened from above downward, and concave anteriorly; the inner 
two-thirds are cylindrical and convex anteriorly, and it extends 
Fig 33. 
almost horizontally between the sternum and scapula, the two ex- 
tremities being respectively termed the sternal1 and acromial'1. 
Describe the chief points presented by the clavicle, com- 
mencing at the outer extremity. 
The upper surface has impressions, that in front for the deltoid,7 
that behind for the trapezius; at the outer end is a facet"1 articu- 
lating with the acromium process of the scapula; at the posterior 
border, beneath, is the conoid tubercle,4 just above the coracoid 
process of scapula, for the conoid ligament; extending from the 
tubercle, forward and outward, nearly to the outer end of the 
anterior border is the oblique line for the trapezoid ligament; occa- 
sionally at the centre of the anterior* border of the outer third is 
the deltoid tubercle. The under surface of the middle portion pre- 
sents the subclavian groove3 for the same named muscle—here 
appears the nutrient foramen directed outward; the inner third of 
the superior border bears an impression for the sterno-mastoid 
muscle5 (A, Fig. 33), while the inner half of the anterior margin 
has another impression for the pectoral is major muscle. Beneath 
the posterior border of the sternal end is the rhomboid impression,5 
for the rhomboid or costo-clavicular ligament. The sternal end1 
is triangular in form, its inner surface for articulation with the 
sternum, this surface being continuous with a facet beneath, for 
articulation with the first costal cartilage. 76 
ESSENTIALS OF HUMAN ANATOMY. 
Give its development. 
By two centres; one for the shaft earliest in the body (thirtieth 
day); one for sternal end (eighteenth to twentieth year); uniting 
about the twenty-fifth year. 
Give the muscular attachments 
Sterno-cleido-mastoid, trapezius, pectoralis major, deltoid, sub- 
clavius, sterno-hyoid, and platysma. 
Describe the scapula. 
The shoulder-blade, a large, flat, triangular bone, extends from 
the first to the eighth ribs on the back and side of the thorax, its 
posterior margin lying nearly parallel to, and one inch from the 
spinous processes of the vertebrae. 
The venter (anterior surface) or subscapular fossa1 is concave, 
presents some transversely oblique ridges *, *,!, for the tendinous 
intersections of the subscapular muscle, and a marginal surface10 
Fig. 34. 
Fig. 35. 
along the inner border—triangular above and below, linear between 
—for the serratus magnus muscle. The angle is the transverse 
depression at its upper part where the fossa is deepest. 
The dorsum2 (posterior surface) (Fig. 35) is divided by a promi- 
nent bony ridge, the spine10, affording attachment to the deltoid BONES OF THE UPPER EXTREMITY. 
77 
and trapezius muscles and ending in the acromion process u, into the 
supra-1 and infraspinatus2 fossa, for the origin of similarly named 
muscles; in the latter is the nutrient foramen13. The external 
border presents a marginal surface?, divided by the oblique line at 
the junction of the lower and middle thirds, into two surfaces, the 
lower for the teres major, the upper for the teres minor muscle; 
about the junction of the middle and upper thirds of this border 
is a groove for the dorsalis scapulae vessels. The spine posteriorly 
presents a triangular surface11, over which plays the trapezius 
muscle. 
The acromion process13 (summit of the shoulder) is a triangular 
flattened process, curving outward, forward, and upward, to over- 
hang the glenoid fossa; giving attachment along its outer margin 
to the deltoid; its inner margin, the trapezius; by its apex to the 
coraco-acromial ligament; and having on its inner margin, behind 
the apex, an articular facet9 (Fig. 34) for the clavicle. 
Describe the coracoid process of the scapula. 
The coracoid process* (Fig. 34)14; (Fig. 35) (like a crow’s beak) 
rises by a- broad base from the upper part of the neck of the 
scapula, curving over the inner upper part of the glenoid cavity. 
To the anterior margin, near the tip, is attached the pectoralis 
minor muscle, and from its apex arise the short head of the biceps 
and the coraco-brachial muscle. To the inner side of the root is a 
rough impression for the conoid ligam.ent, whence runs obliquely 
forward and outward on its upper surface a ridge for the trapezoid 
ligament. 
Describe the scapular borders. 
The superior border 3—the shortest—presents, at the base of the 
coracoid, the suprascapular notch4 (Fig. 35), becoming a foramen 
when the transverse ligament is in situ, through which passes the 
suprascapular nerve, above which passes the suprascapular artery; 
from the border, just internal to the notch, arises the omo-hyoid 
muscle. The axillary border5—the thickest—presents just below 
the glenoid fossa a rough surface8 for the long head of the triceps 
muscle, succeeding which is a longitudinal groove for part of the 
subscapular muscle. The vertebral border *■—the longest—presents 78 
ESSENTIALS OF HUMAN ANATOMY. 
an anterior lip for the serratus magnus muscle, a posterior lip for the 
supra- and infra-spinatus muscles, and an intermediate space for the 
levator anguli scapulae above, for the rhomboideus minor from the 
edge of the triangular base of the spine, and for the fibrous arch of 
the rhomboideus major muscles below. 
Give the points of interest connected with the angles. 
The superior angle4 (Fig. 34) affords partial attachment to the 
serratus magnus, to the levator anguli scapulae, and supra-spinatus 
muscles. The inferior angle7 (Fig. 35) affords attachment to the 
teres major muscle, part of the serratus magnus, and (at times) a few 
fibres of the latissimus dorsi. The external angle or head6 presents 
a shallow pyriform glenoid fossa10 (Fig. 34) for the head of the 
humerus, deepened, in the fresh state, by the glenoid ligament 
attached around its circumference, from the upper part of which 
the long head of the biceps flexor cubiti arises. The neck8 (Fig. 
35) is the slightly depressed surface surrounding the head; the 
surgical neck is well posterior to the head, passing through the 
suprascapular notch4-8 (Fig. 35). 
How is this bone developed ? 
By seven centres; one for body (second foetal month); two for 
coracoid (one at first year, one at fifteenth to seventeenth year); 
two for acromion; one for vertebral border; one for inferior angle 
(all these last, fifteen to seventeen years); coossification (twenty- 
two to twenty-five years). 
Give the muscular attachments. 
Subscapular, supra- and infra-spinatus, deltoid, trapezius, omo- 
hyoid, serratus magnus, levator anguli scapulae, rhomboideus minor 
and major, triceps, teres minor and major, biceps, coraco-brachial, 
pectoralis minor, platysma, occasionally latissimus dorsi. 
The Arm. 
Describe the chief processes and the general character- 
istics of the humerus. 
This, the only arm bone, articulates above with the scapula, THE A EM 
79 
below with the ulna and radius. The upper extremity, the head2, 
nearly hemispherical, facing upward, inward, and slightly back- 
ward, forms, with the glenoid fossa of the scapula, 
the shoulder or scapulo-humeral joint. Best marked 
superiorly is the constriction called the anatomical 
neck:i, indicating the capsular attachment above; 
external to the head is the greater tuberosity1 with 
three facets for the supra- and infra-spinatus and 
teres minor muscles; in front, directed inward and 
forward, is the lesser tuberosity5 for the subscapular 
muscle; commencing between these two projections, 
and extending for the upper third of the bone, is 
the bicipital groove, passing obliquely downward and 
inward, lodging the long head of the biceps muscle; 
into the anterior lip 7 of this groove is inserted the 
pectoralis major muscle, into the posterior lip8 the 
latissimus dorsi and teres major; while about the 
centre of the inner border of the bone is a rough 
impression for the coraco-brachial muscle, just below 
which is the nutrient canal™, directed downward. 
The constriction beneath the tuberosities is called 
the surgical neck. The shaft, cyliudrical above, pris- 
moid and flattened below, presents upon the mid- 
dle of its outer surface a roughness9 for the deltoid 
muscle, and below it, winding from behind forward 
and downward, on the back of the bone, is the mus- 
culo-spiralgroove, for themusculo-spiral nerve and superior profunda 
artery, internal and external to which arise the inner and outer 
heads of the triceps muscle. The lower extremity presents an inner14 
(very prominent) and an outer condyle™, extending from each of 
which, upward on the shaft, are the internal16 and external condyloid15 
ridges15; from the external ridge arise the external lateral ligament 
and extensor and supinator muscles; from the inner condyle and 
ridge arise the internal lateral ligament and the flexor and round 
pronator muscles. Projecting from the lower front portion of the 
outer condyle is the radial head11 (capitellum), for the head of the 
radius; while internal to this, extending from the anterior to the 
posterior surface of the bone, is the pulley-like trochlear surface12 
Fig. 3fi. 80 
ESSENTIALS OF HUMAN ANATOMY. 
for the greater sigmoid cavity of the ulna. The eoronoid fossa17 in 
front of the trochlea receives the eoronoid process of the ulna 
during flexion of the forearm, while the olecranon fossa, similarly 
placed behind, accommodates the tip of the olecranon during 
extension. 
How is the humerus developed ? 
. By seven centres: one for shaft (fifth foetal week); one for head 
(first to second year); one (sometimes two) for tuberosities (second 
to third year; by fifth year the centres for head and tuberosities 
have coossified); one for radial head (second year); one for internal 
condyle (fifth year); one for trochlea (twelfth year); one for 
external condyle (thirteenth to fourteenth year). The lower 
centres are all coossified with the shaft by the sixteenth or seven- 
teenth year except that for the internal condyle, which unites at 
eighteen years, while the head unites at the twentieth year. 
Give the muscular attachments. 
The supra- and infra-spinatus, teres minor, subscapular, pecto- 
ralis major, latissimus dorsi, teres major, deltoid, coraco-brachial, 
brachialis anticus, triceps, subanconeus, pronator radii teres, flexor 
carpi ulnaris, palmaris longus, flexor digitorum sublimis, flexor 
carpi radialis, supinator longus, extensor carpi radialis longior and 
brevior, extensor communis digitorum, extensor minimi digiti, 
extensor carpi ulnaris, anconeus, and supinator brevis. 
The Forearm. 
Describe the ulna. 
This, the inner forearm bone1, longer than the radius, forms the 
greater part of the articulation with the humerus, while it is 
excluded from the wrist-joint by the interarticular fibro-cartilage. 
Its upper extremity forms the point of the elbow. The olecranon 
process4 presents upon its anterior part a saddle-shaped articular 
surface which, with its continuation on the eoronoid process, is 
the greater sigmoid cavity2 for the trochlea of the humerus; continu- 
ous with this upon the outer side is the lesser sigmoid cavity3 for the 
head of the radius; to the posterior surface is attached the triceps THE FOREARM. 
81 
tendon, and the apex is accommodated by the olecranon fossa of 
the humerus during extension. Projecting forward below the ole- 
cranon is the coronoidprocess*, fitting into the same 
named fossa of the humerus during flexion, its upper 
surface forming part of the greater sigmoid cavity ; 
it presents, where it joins the shaft, a tubercle for 
the oblique ligament, and a rough impression for the 
brachialis anticus muscle above and internally. At 
the front is a small eminence for the flexor sublimis 
digitorum, whence descends a ridge for the pronator 
radii teres. The shafti1, large and prismatic above, 
smaller and rounded below, has on its anterior sur- 
face the nutrient foramen, directed upward, and by 
its external sharp border7 affords attachment to the 
interosseus ligament. The lower carpal extremity, 
or head*, articulating, by its outer surface, with the 
sigmoid cavity of the radius, and, by its lower, with 
the triangular fibro-cartilage, has projecting inter- 
nally and behind, the styloid process9, to whose apex 
is attached the internal lateral ligament, to a de- 
pression at its base the fibro-cartilage; upon the 
posterior surface is a groove for the tendon of the 
ul no-carpal extensor. 
Fig. 37 
How is this bone developed ? 
By three centres; one for shaft (eighth foetal week); one for 
head (fourth year) ; one for olecranon (tenth year, joining shaft 
at sixteenth year); head coossified with shaft by twentieth year. 
Give the muscular attachments. 
Triceps, anconeus, flexor carpi ulnaris, brachialis anticus, pro- 
nator radii teres, flexor sublimis and profundus digitorum, flexor 
longus pollicis (occasionally), pronator quadratus, flexor and 
extensor carpi ulnaris, anconeus, supinator brevis, extensor ossis 
metacarpi and secundi internodii pollicis, and extensor indicis. 
Describe the radius. 
Shorter than the ulna, situated upon the outer side of the fore- 
arm, with a small upper extremity, forming only a small part of 82 
ESSENTIALS OF HUMAN ANATOMY. 
the elbow-joint, its lower end is large, forming the chief part of 
the wrist-joint. It is slightly curved, and of a prismatic form. 
The head11 (upper extremity) is cylindrical, with slightly cupped 
upper surface, articulating with the radial head of the humerus, 
by its sides, with the lesser sigmoid cavity of the ulna and the 
orbicular ligament by which it is embraced; the constriction 
beneath the head is the neck12; below, and to the inner side, is the 
tuberosity13, rough toward its posterior margin for the biceps tendon, 
smooth in front for a bursa; the shaft10 is prismoid, curved out- 
ward, smaller above than below, having a sharp internal interosseous 
border7 for the interosseous ligament, with the nutrient foramen 
directed upward at the junction of the middle and upper thirds of 
the anterior surface. 
The lower carpal extremity15 has on its lower face an articular 
surface divided by a slight ridge into two facets for the semilunar 
and scaphoid bones; upon its inner side the shallow sigmoid cavity 
for the ulnar head; externally the styloid process™ giving attach- 
ment by its apex to the external lateral ligament, by its base to the 
supinator longus muscle; and on its posterior and external convex 
surfaces are five grooves for the extensor tendons. 
How is this bone developed ? 
By three centres; one for shaft (eighth foetal week); one for 
carpal extremity (second year); and one for head (fifth year, 
joins shaft at puberty); bone coossified by about twentieth year. 
Give the muscular attachments. 
The biceps, the supinator brevis, flexor digitorum sublimus and 
longus pollicis, pronator quadratus, the extensor ossis metacarpi 
and primi internodii pollicis, pronator radii teres, and supinator 
longus. 
The Hand. 
Into what segments is the hand divided ? 
Into the carpus (eight bones); metacarpus (five bones); and 
phalanges (fourteen hones); total, twenty-seven bones. THE HAND 
83 
Describe the arrangement of the carpal bones. 
They are placed in two rows of four each; thus, enumerating 
from the radial to the ulnar side, with palm upward; First, or 
proximal row: scaphoid®, semilunari, cuneiform0, pisiformp. 
Second, or distal row : trapezium*, trapezoid1 ,*, os magnum7, unci- 
form«. 
Fig. 38. 
With how many bones does each articulate? 
Scaphoid, five; semilunar, five; cuneiform, three; pisiform, 
one; trapezium, four; trapezoid, four; os magnum, seven; unci- 
form, five; total, thirty-four. 
Describe the chief peculiarities of each bone. 
The scaphoid8 (boat-shaped) has on the thumb side a tuberosity, 
a transverse groove on the dorsum parallel to the convex articular 
surface for radius; facets for os magnum and semilunar bones on 
its inner lower face; 'on its lower for the trapezium and trape- 
zoid. 
The semilunar1 (half-moon) presents a convex facet above for 
radius; on its outer face a semilunar facet for scaphoid; on its 
lower, a concave one for os magnum; a quadrilateral one on the 
inner face for cuneiform. 
The cuneiform0 (wedge-shaped) has an oval facet in front for 
pisiform ; one external for semilunar; an inferior concave facet for ESSENTIALS OF HUMAN ANATOMY. 
unciform ; a superior convex facet for interarticular fibro-carti- 
lage. 
Thepisiformv is rounded, with one ovoidal facet for cuneiform. 
The trapezium} is obliquely grooved on its palmar surface for the 
tendon of the flexor carpi radialis; superiorly is a concave facet 
for scaphoid ; below, a saddle-shaped one for thumb-metacarpal; 
internally, one large concave facet for trapezoid, and a smaller for 
second metacarpal. 
The trapezoid11 is wedge-shaped, apex palmar, has four articular 
surfaces touching, separated by sharp edges, the external for 
trapezium; inferior (like a ridge-roof), for second metacarpal; 
internal, for os magnum; superior, for scaphoid. 
The os magnum7 has superiorly a convex head for scaphoid and 
semilunar, a neck and body; below, facets for three metacarpal 
bones; externally, one for trapezoid; internally, one for unciform. 
The unciformu is triangular, has a sigmoid internal articular 
facet for cuneiform; two facets below for fourth and fifth meta- 
carpals; one, external, for os magnum; from the palmar surface 
projects the curved unciform process. 
When do these bones ossify ? 
Os magnum and unciform, during first year; cuneiform, third 
year; trapezium and semilunar, fifth year; scaphoid, sixth year; 
trapezoid, during eighth year; pisiform, about twelfth year. 
(The muscular attachments to the carpal and tarsal bones will 
be given under the Muscular System.) 
Describe the metacarpal bones. 
They are five long bones, with shaft, head, and base. The first 
metacarpal (sometimes considered a phalanx) is shorter, has only 
one facet on base, and has one ossific centre for shaft (eighth foetal 
week), and one for base (third year). The second metacarpal has 
four facets on base for trapezium, trapezoid, os magnum, and third 
metacarpal; it, in common with the rest, has one ossific centre for 
shaft (eighth foetal week), and one for head (third year; they 
coossify by twentieth year). The third metacarpal articulates only 
with the os magnum, on the ulnar side has two small facets for 
fourth metacarpal, a single facet on the radial side for second THE THIGH. 
85 
metacarpal, and the outer angle of its base is much prolonged. 
The fourth metacarpal has two facets for unciform and os magnum, 
a single facet on ulnar side for fifth metacarpal, and two small 
ones on radial side for third metacarpal. The fifth metacarpal 
articulates with unciform by a concavo-convex facet, has only a 
lateral facet on the radial side for fourth metacarpal, and on the 
ulnar side a prominent tubercle for the extensor carpi ulnaris 
tendon. 
Describe the phalanges. 
Fourteen in number—three for each finger, two for thumb—they 
are long bones, having a shaft, base, and condyles, except those of 
the distal row. The bases of first row, cup-shaped, articulate with 
heads of the metacarpals; those of second and third have a double 
concavity, separated by a median ridge, and articulate with the 
condyles of the row above ; the distal extremities of the ungual 
phalanges have rough, horse-shoe shaped tubercles on their palmar 
surfaces for attachment of the pulp of the finger; they ossify by 
one centre for the shaft (eighth foetal week), and one for base (third 
to fifth year); uniting, from eighteen to twenty years. 
LOWER EXTREMITY. 
The Thigh. 
Describe the femur. 
It is the longest bone of the skeleton, and inclines toward its 
fellow to bring the knee-joint near the centre of gravity during 
walking, this obliquity being greater in the female, from the breadth 
of the pelvis, and in a short than a tall person of either sex. 
The head2, forming rather more than a hemisphere, directed 
upward, inward, and forward, has behind and below its centre an 
ovoid depression for the ligamentum teres. The necW, joining the 
head with the shaft, is flattened and pyramidal; in the adult male 
it forms an obtuse angle with the shaft; in the female it approaches 
a right angle; in very old and debilitated subjects its direction 
becomes horizontal, The great trochanter4 is a large, irregular, 86 
ESSENTIALS OF HUMAN ANATOMY. 
quadrilateral eminence, directed upward, outward, and backward, 
marked on its external surface by a diagonal line for the gluteus 
medius; below and behind this is a smooth surface for a bursa 
beneath the gluteus maximus; in front, from above downward, are 
inserted the internal obturator and gemelli muscles, 
the pyriformis, and the gluteus minimus; upon its 
inner surface is the digital fossa for the tendon of 
the obturator interims muscle. 
The lesser trochanter6, small and conical, projects 
from the lower back part of the base of the neck, 
receiving the insertion of the psoas muscle above, 
and the iliacus below. 
The anterior*’ and posterior intertrochanteric lines 
connect these processes, the latter being the more 
prominent, while to the former is attached the an- 
terior portion of the capsular ligament. Extending 
from the middle of the posterior intertrochanteric 
line, for about two inches down the shaft, is the 
linea quadrati for the quadratus femoris muscle. 
The shaft1, broad and cylindroid at either ex- 
tremity, narrow and triangular in the centre, slightly 
curved forward, has its nutrient foramen at the junc- 
tion of the middle and lower thirds of its posterior 
surface, directed upward; and from its anterior 
surface arise the crureus and subcrureus muscles. 
The linea aspera, a prominent longitudinal ridge 
occupying the middle third of the posterior sur- 
face, has an external and an internal lip, and an 
intermediate space; above, it divides into three 
lines, one directed upward to base of greater, one to base of lesser 
trochanter, a third, the most internal continuous with the anterior 
intertrochanteric line, forming, with it, the spiral line6, while below 
the linea aspera bifurcates to inclose the smooth popliteal space, the 
inner division grooved for the femoral vessels. In general terms, 
this line and its subdivisions have attached the following muscles: 
the vastus interims and externus, the pectineus, the three adduc- 
tors, the biceps and gluteus maximus. 
Of the two condyles, the internal8 is the longer by about half an 
Fig. 39. THE PATELLA. 
87 
inch, to bring both condyles on the same horizontal plane in the 
normally oblique position of the femur; above each condyle, 
behind, is a depression for the gastrocnemius (above the external the 
plantar muscle also originates); separating them is the intercon- 
dyloid notch, to whose sides are attached the crucial ligaments; in 
front, the condyles form a continuous cartilaginous-covered articu- 
lar surface ; the outer, as well as the inner condyle, presents a tube- 
rosity9-u upon its free surface for the lateral ligaments, beneath 
which, on the outer condyle, is a groove10 for the tendon of origin 
of the popliteus muscle; above the internal tuberosity11 is a small 
tubercle for the tendon of the adductor magnus. 
Give the development of the femur. 
By five centres; one for shaft (fifth foetal week); one for condyles 
(ninth foetal month); one for head (end of first year); one for greater 
trochanter (fourth year); one for lesser trochanter (thirteenth to 
fourteenth year); all coossified by twentieth year in the reverse 
order of their appearance. 
Give the muscular attachments 
The three glutei, pyriformis, two obturators, gemelli, quadratus, 
psoas, iliacus, two vasti, biceps, pectineus, three adductors, crureus, 
subcrureus, gastrocnemius, plantaris, and popliteus. 
The Patella. 
Describe the patella. 
It is flat, triangular, placed at front of the knee-joint, and, being 
developed in the quadriceps tendon, is considered a sesamoid bone 
by some; the convex anterior surface is roughened; the posterior 
surface is divided by a vertical ridge into two smooth facets for either 
femoral condyle, the outer being the broader and deeper; the apex 
gives attachment to the ligamentum patella; and the superior and 
lateral borders to the rectus femoris, crureus, and vasti muscles. It 
is developed by one centre (about three years); the muscular attach- 
ments have been already given. 88 
ESSENTIALS OF HUMAN ANATOMY 
The Leg. 
Describe the tibia. 
The shin-bone, situated at the inner front part of the leg, is only 
second in length to the femur; the head2-3, or upper extremity, is 
large and expanded on each side into two lateral tuberosities2-3, 
bearing upon their upper surfaces smooth concave ovoidalfacets for 
the femoral condyles, between which is the vertical, 
bifid spine* for the extremities of the semilunar 
fibro-cartilages, the depressions in front and behind 
its base giving origin to the crucial ligaments. Be- 
low, medianally, in front of the head, is the tuber- 
cle5 for the ligamentum patellae; separating the 
tuberosities behind is the popliteal notch, giving 
attachment to the posterior crucial ligament; on 
the posterior surface of the inner tuberosity is a 
transverse groove for the insertion of the semi- 
membranosus tendon; upon the back of the outer 
tuberosity, facing downward, is a facet for the head 
of the fibula; running obliquely from this facet, 
downward and inward, on the posterior surface, is 
the oblique line for the popliteal fascia, parts of the 
soleus, flexor longus digitorum, and tibialis posticus 
muscles; just below the line, directed downward, 
is the nutrient canal, the largest in the skeleton. 
The prismoid shaft1 has three borders, of which 
the anterior, called crest or shin6, and the external 
or interosseous ridge, for the interosseous membrane, 
only are of importance. The lower extremity1, 
smaller than the upper, has an inferior concave 
surface for the astragalus, an external rough trian- 
gular surface for articulation with the fibula; it 
is grooved posteriorly for the flexor longus pollicis tendon; has 
projecting downward, internally, the internal malleolus8, which 
articulates by its outer surface with the side of the astragalus, is 
grooved behind for the tibialis posticus and flexor longus digitorum 
tendons, and has attached to its tip the internal lateral ligament. 
Fig. 40. THE LEG. 
89 
How is this bone developed ? 
By three centres: One for shaft (seventh foetal week); one for 
head (at birth); one for lower end (second year); bone coossified 
by twentieth year (some authors say twenty-fifth year). 
Give the muscular attachments. 
Semimembranosus, tibialis anticus and posticus, biceps, extensor 
and flexor longus digitorum, sartorius, gracilis, semitendinosus, 
popliteus, soleus, and quadriceps femoris. 
Describe the fibula (peroneal bone). 
It is long, slender, and is placed externally nearly parallel to 
the tibia. 
The head10 or upper end articulates by a flattened facet with 
the external tibial tuberosity3, and is prolonged upward behind 
into the styloid process for the biceps tendon and the external 
lateral ligament; below and behind is attached the long external 
lateral ligament. 
The shaft?, triangular and twisted, has three ridges, the internal 
or interosseous ridge being for same-named ligament; about the 
middle of the anterior internal surface is the nutrient foramen 
directed downward. The external malleolus11 forming the lower ex- 
tremity, longer than the internal, articulates by its inner surface 
with the outer side of the astragalus; is grooved behind for the 
peroneus longus and brevis tendons; to its summit is attached the 
middle, and to rough depressions in front and behind the anterior 
and posterior fasciculi of the external lateral ankle-ligament. 
Describe its development. 
By three centres.- One for shaft (eighth foetal week); one for 
malleolus (second year); one for head (fourth year); bone coossi- 
fied by twenty-fifth year, but, contrary to rule, the lower epiphysis 
unites first. 
Give the muscular attachments. 
Biceps, soleus, three peroneals, the extensor and flexor of the 
great toe, and extensor longus digitorum, and tibialis posticus. 90 
ESSENTIALS OF HUMAN ANATOMY. 
The Foot. 
Into what segments are the bones of the foot divided ? 
Into the tarsus (7); metatarsus (5); and phalanges (14); total, 26 
bones. 
Name the tarsal bones. 
Calcaneum3 (os calcis), astragalus1, cuboid8, scaphoid4, internal5, 
middle6, and external7 cuneiform. 
Give the chief peculiarities of each tarsal bone. 
The astragalus1 has a large rounded head2, a neck, a body', supe- 
riorly a trochlear surface broader in front than behind, for the tibia, 
and continuous with it on either side facets for the internal and 
external malleolus; the under surface presents two articular facets 
—that behind for the calcis, that in front partly for calcis but 
chiefly for the calcaneo-scaphoid ligament—separated by a groove 
for the calcaneo-astragaloid ligament, running obliquely forward 
and outward; it articulates with the tibia, fibula, os calcis, and 
scaphoid, and is developed by one centre (seventh foetal month). 
The os calcic, the largest tarsal bone, forms by its tuberosity3 be- 
hind the heel, has a groove on its upper surface to correspond to 
that of the astragalus; behind and in front of which are two artic- 
ular facets for the same bone: on the inner side projects the susten- 
taculum tali supporting the internal articulating surface; beneath 
this process the inner surface of the bone is deeply concave for the 
flexor tendons, plantar vessels, and nerves; its anterior concavo- 
convex surface articulates with the cuboid; on the under surface 
are an inner and outer tuberosity, it articulates with the astragalus 
and cuboid, and is developed from two centres, one for main mass 
(sixth foetal month); one for tuberosity (tenth year); union after 
puberty. 
The cuboid has one articular surface each for os calcis, external 
cuneiform, the fourth and fifth metatarsals, and sometimes the 
scaphoid; upon the under surface is a deep groove for the peroneus 
longus tendon, and behind this a ridge terminating externally in a 
tuberosity, it is developed from one centre (ninth foetal month). THE FOOT. 
91 
The scaphoid, situated internally, is concave behind for the head 
of the astragalus; is convex in front with three facets for the three 
cuneiform bones; externally is a facet for the cuboid; and intern- 
ally, below, is the tuberosity for part of the pos- 
terior tibial tendon; it is developed from one 
centre (fourth year). 
The internal cuneiform, the largest, is placed 
at the inner side of the foot, has its base down- 
ward, upon which is the tuberosity for part of 
the tendon of the posterior tibial muscle; in 
front is a kidney-shaped facet for first meta- 
tarsal; externally are two facets for the second 
metatarsal in front, the middle cuneiform be- 
hind; posteriorly a facet for the scaphoid; it 
is developed by one centre (third year). 
The middle cuneiform, the smallest, has its base 
upward, a triangular facet in front for second 
metatarsal, another behind for the scaphoid; 
along the posterior and superior borders of the 
inner face a facet for the internal cuneiform; 
and externally a smooth facet for the external 
cuneiform; it is developed by one centre (fourth 
year). 
The external cuneiform is intermediate in size 
with base upward, has an anterior triangular facet for third meta- 
tarsal; another posterior for the scaphoid; two upon internal sur- 
face for second metatarsal and middle cuneiform; and two upon 
outer surface for fourth metatarsal and for cuboid: it is developed 
by one centre (first year). 
Fig. 41. 
Describe the metatarsal bones. 
These five long bones have prismoid shafts9, anteriorly a head 
for articulation with the phalanges, posteriorly a base articulating 
with the tarsus and one another. 
The first metatarsal is shorter, much stouter, and articulates only 
with the internal cuneiform: developed by one centre for shaft 
(seventh foetal week); one for base (fifth year), united by the 
twentieth year. 92 
ESSENTIALS OF HUMAN ANATOMY. 
The second metatarsal, the longest, articulates posteriorly with 
the middle cuneiform, and laterally with the other cuneiforms, 
presenting, therefore, three facets on base; developed by one centre 
(seventh foetal week) for shaft, one for head (third year), united at 
twenty years. 
The third metatarsal has a facet on base for external cuneiform, 
two on its inner side and one on its outer for the contiguous meta- 
tarsal ; developed like second. 
The fourth metatarsal articulates behind with cuboid, has a facet 
on inner side divided into anterior portion for third metatarsal, a 
posterior for external cuneiform, and externally one facet for fifth 
metatarsal: developed like second. 
The fifth metatarsal has a triangular oblique surface for the 
cuboid, continuous internally with one for fourth metatarsal; ex- 
ternally a tubercular eminence; developed like second. 
Describe the phalanges. 
They resemble closely those of the hand, except that they are 
strongly compressed from side to side, instead of from before back- 
ward : ossification also, similar but later. Thus, the shaft centres 
appear from two to four months, except distal at seventh foetal 
week. 
THE ARTICULATIONS. 
How are the articulations classed ? 
In three divisions; 1. Synarthroses, immovable, as most of cranial 
articulations; 2. Amphiarthroses, including synchondroses, or sym- 
physes, yielding (limited motion), as those between the vertebral 
bodies, the pubic and sacro-iliac symphyses ; 3. Diarthroses, freely 
movable. 
Into what classes are the synarthroses divided ? 
1. Sutura vera, consisting of interlocking serrations, including 
three sub-classes of 8. dentata, when the bony projections are 
tooth-like, as the inter-parietal suture; 8. serrata, when like a fine 
saw, as the inter-frontal; S. limbosa, when the edges are bevelled in 
addition to dentation, as the fronto-parietal. The Sutura notha (false THE ARTICULATIONS. 
93 
sutures) include S. squamosaformed by two overlapping bevelled 
edges, as the squamo-parietal suture; and the S. harmonia, mere 
apposition of roughened surfaces, as the two superior maxillary 
bones. 
2. Schindelysis, where a thin edge is received into a cleft or fissure, 
as the vomer between the superior maxillary bones. 
3. Gomphosis, the insertion of a conical process into a socket, as 
teeth in their alveoli (not really a bony articulation, as teeth are 
not bones). 
How are diarthroses classed ? 
As arthrodia, gliding joints—the articular processes of the verte- 
brae; enarthroses, ball-and-socket joint—hip- or shoulder-joints: 
ginglymus, hinge-joint—elbow-joint; diarthrosis rotatoria, or lateral 
ginglymus, a pivot turning within a ring, or a ring on a pivot, as 
the superior radio-ulnar and atlo-odontoid. 
What varieties of motion do joints enjoy? 
Flexion, extension, adduction, abduction, circumduction (a com- 
bination in succession of the four preceding), rotation, and gliding. 
What structures are essential to the formation of each of 
the three classes of articulations ? 
For synarthroses, two or more bones, an interposed layer of 
fibrous tissue (sutural ligament) or, perhaps, cartilage (base of 
the skull); symphyses, an interposed bond of fibro-cartilage, with 
strong bands of white fibrous tissue, i. e., ligaments (ligaments 
are sometimes composed of yellow elastic tissue, as the liga- 
menta subflava or ligamentum nuchse); diarthroses, two or more 
cartilaginous-coated surfaces (reducing friction), sometimes inter- 
articular fibro-cartilages to deepen joint surfaces, as those of the 
knee- and temporo-maxillary joints, a complete fibrous capsule, 
and often additional ligamentous bands, some inter-articular, i. e., 
within the joint cavity, and a synovial (serous) membrane lining 
the interior of the capsule, but not extending upon the cartilages; 
a similar membrane also forms sacs (bursae) outside the joints, with 
which they often communicate, serving to reduce friction of the 
tendons, ligaments, etc.; the layer of bone beneath the articular 94 
ESSENTIALS OF HUMAN ANATOMY. 
cartilage is denser, contains neither Jlaversian canals nor canali- 
culi, and has larger lacunae. 
What is the rule as regards the nerve supply of joints ? 
The interior of the joint, the muscles moving it, and the skin 
over their insertions, are supplied by the same trunk or trunks of 
nerves (this explains the reflex contractions of diseased joints). 
Describe the vertebral articulations. 
Formed by the contiguous surfaces of the vertebral bodies and 
articular processes, their ligaments are as follows : 
An intervertebral connecting fibro-cartilage, between the bodies of 
all true vertebrae, except the atlas and axis. 
An anterior common ligament passing medianally over the fronts 
of the vertebral bodies, most firmly attached to their margins. 
A posterior common ligament, similarly disposed behind. 
Short intervertebral ligaments, fibres running at most over three 
vertebrae, firmly uniting the bodies where the anterior and pos- 
terior common ligaments are deficient. 
Ligamenta subflava, of yellow elastic tissue, connecting the 
laminae. 
Supra- and inter-spinous, the former connecting the tips, the latter 
the remainder of the spinous processes. 
Capsular6, enclosing the articular processes, and lined with syno- 
vial membrane. 
Inter-transverse, connecting transverse processes; nerves, spinal 
in each region; arteries, vertebral and ascending cervical arteries 
in neck, intercostals in dorsal region, lumbars in loin. 
Describe the occipito-atloid articulation. 
It is a ginglymo arthrodial joint formed by the condyles of the 
occipital bone and the superior articulating processes of the atlas. 
Its ligaments are, 
An anterior occipito atlantal2 (Fig. 42), extending from the an- 
terior margin of the foramen magnum to the anterior arch of the 
atlas, about one inch broad, blending on either side with the 
capsular ligaments. 
A posterior occipito-atlantal, much broader, from the posterior 
margin of the foramen magnum between the condyles, to the pos- THE ARTICULATIONS. 
95 
tero-superior border of the posterior arch of the atlas, and is incom- 
plete on each side for the ingress of the vertebral artery, and egress 
of the suboecipital nerve. 
Two capsular ligaments'1, lined with synovial membrane, surround- 
ing the articular surfaces. 
Two lateral {ox anterior oblique), passing upward and inward from 
the transverse process beyond the vertebral foramen to the inner 
edge of the jugular foramen; 
nerve, suboecipital; arteries, from 
vertebral. 
Describe the atlo-axoidean 
points. 
The lateral joints are arthrodia, 
that 1 etween the atlas and odon- 
toid process a double diarthrosis 
rotatoria. The ligaments of the 
lateral joints and arches are, 
The anterior atlanto-axoidean4,, 
membranous, passing between lower front border of atlas to front 
of the axis. 
The posterior atlanto-axoidean, stretching between the postero- 
inferior edge of the ring of the atlas to the superior edge of the 
arch of the axis behind ; it is pierced on each side by the second 
spinal nerve. 
The anterior1-3 and posterior common ligaments are continued over 
the median portions of the above to the occiput. 
Two capsulars60, synovial-lined, surrounding the articulating 
processes. 
The ligaments of the central atlanto-axoidean joints are: 
The transverse2 (Fig. 43), extending between the tubercles on the 
inner surface of each lateral mass of the atlas; it holds the odon- 
toid process in place, and between the two is a synovial membrane 
surrounded by a capsule, the odonto-transverse joint; between the 
odontoid process and the posterior surface of the anterior arch of 
the atlas, is the atlo-odontoid articulation, surrounded by a capsule 
lined with synovial membrane; passing upward and downward, 
are two strong vertical bands, attached above to the cranial surface 
Fig. 42. 96 
ESSENTIALS OF HUMAN ANATOMY. 
of the basilar margin of the foramen magnum, below, to the upper 
half of the body of the axis, forming the occipito-axiodean liga- 
ment3 or vertical portion of the crucial ligament; nerves, all these 
joints are supplied by the second cervical or loop between it and 
the suboccipital; arteries, are branches of vertebral. 
What other ligaments connect the axis and occiput ? 
The posterior common ligament1 extends upward, to be attached 
far up the basilar process; beneath this is, 
The occipito-cervical or cervico-basifar ligament, attached above to 
the basilar groove of the occiput, below, to the third cervical 
Fig. 43. 
Fig. 44. 
body and that of the axis; (next comes the vertical part of the 
crucial already described); deepest of all are the, 
Occipito-odontoid, or checlc\ extending from the sides of the apex of 
the odontoid to inner edge of the anterior portion of the occipital 
condyles, while stretching between the odontoid tip and the under 
surface of the basilar process close to the foramen magnum, is the 
Central occipito-odontoid, or ligamentum suspensorium. 
Describe the temporo-maxillary articulation. 
The upper compartment is arthrodial, formed by the glenoid 
fossa and eminentia articularis of the temporal bone and the upper 
surface of the fibro-cartilage; the lower is ginglymoid, between 
the under surface of the fibro-cartilage and the condyle of the 
lower jaw. The ligaments are capsular, passing between maxillary 
and temporal bones near their margins, consisting of ligamentous 
fibres, which are thicker at certain parts, and are described as The articulations. 
97 
The external lateral ligament5, attached above to nearly the whole 
length of the lower edge of the zygoma and its tubercle, below to 
the outer side of the neck of the condyle of the jaw. 
The short internal lateral ligament, extending between the spine 
of the sphenoid and inner edge of the glenoid fossa, and a ridge 
on the inner side of the neck of the condyle. 
The long internal lateral ligament, stretching between the spine 
of the sphenoid and the forepart of the tip of the inferior dental 
foramen. 
The inter-articular ftbro-cartilage, concavo-convex on the upper 
surface, concave obliquely transversely below, dividing the joint 
into two separate synovial cavities. 
The stylo-maxillary ligament6, extending from the styloid process 
to the angle of the jaw, is really a process of the deep fascia; 
nerves, the masseteric and auriculo-temporal branches of the infe- 
rior maxillary nerve; arteries, temporal, middle meningeal, ascend- 
ing pharyngeal, posterior auricular, tympanic branch of the 
internal maxillary and ascending palatine. 
Describe the costo-vertebral articulations. 
These are each formed (1) between the head of a rib and the 
bodies of two adjoining vertebrae (except first, tenth, eleventh, 
and twelfth, which articulate with but one vertebra each), being 
ginglymoid; and (2) between the tubercle of each rib (except 
eleventh and twelfth) and the transverse process of a vertebra, 
and is arthrodial. 
Describe the costo-central articulations. 
Ginglymoid, the ligaments are-(l): 
A capsular ligament4, attached all 
around each articular surface, the syno- 
vial liuing being subdivided into two 
cavities by the 
Inter-articular, or costo-vertebral liga- 
menft, passing between the ridge on the 
head of the rib to the intervertebral 
hbro-cartilage. 
The stellate ligament?, arising from the 
Fig. 45. ESSENTIALS OF HUMAN ANATOMY. 
anterior surface of the neck of the rib, whence the fibres radiate 
to the vertebra next above and below to the one the rib belongs 
to, and to the intervertebral disk; nerves, anterior branches of 
spinal nerves; arteries, the intercostals. 
Describe the costo-transverse articulations. 
Arthrodial, ten in number, their ligaments are: 
Capsular, attached beyond the margins of the articular facets. 
Superior costo-transverse* (except first rib), passing between upper 
border of neck of rib to lower margin of transverse process of the 
vertebra above. 
Middle costo-transverse, connecting the back of neck of rib with 
the contiguous portion of transverse process of vertebra to which 
rib belongs. 
Posterior costo-transverse, stretching from the tip of transverse 
process to rough projection beyond facet on the tubercle of rib; 
nerves, posterior branches of dorsal nerves; arteries, intercostals 
and posterior spinal. 
Describe the (1) costo-sternal articulations, (2) the connec- 
tion between the ribs and costal cartilages, and (3) the 
interchondral joints. 
(1) The first is synarthrodial, the other six joints are ginglymoid. 
The costal (2) cartilages are firmly attached to the cup-like depres- 
sion at the end of each rib, and by the periosteum continued over to 
form the perichondrium; in like manner, the cartilage of the first 
rib unites with the sternum. The cartilages of the remaining six 
ribs are bound to the sternum by a, 
Complete capsular ligament, the anterior and posterior thicker 
segments sometimes described as, 
Anterior and posterior costo-sternal ligaments. Occasionally there 
is an interarticular ligament, notably in the second costal joint, 
dividing the synovial cavity into two. 
The (3) interchondral articulations, arthrodial, are usually, but not 
always, found between the edges of the fifth to tenth ribs, inclusive, 
having each an interchondral ligament and a capsular, lined with 
synovial membrane ; they are commonly found only from the sixth 
to the ninth cartilages; in addition, the costo-xiphoid ligament THE ARTICULATIONS. 
99 
binds the xiphoid cartilage and sixth and seventh cartilages 
together; nerves, intercostals; arteries, internal mammary or its 
branches. 
Describe the ligaments of the sternum. 
All three segments are bound together by the so-called, 
Anterior and posterior ligaments, with a layer of cartilage between 
the manubrium and gladiolus (an amphiarthrodial joint, that be- 
tween ensiform cartilage and gladiolus being synarthrodial). 
Describe the sacro-vertebral articulation. 
Similar to other vertebral articulations, but has, in addition, 
The sacro-lumbar ligament, extending from the transverse 
processes, pedicles, and body of the fifth lumbar vertebra to the 
non-articular portions of the base of the sacrum and periosteum 
of the contiguous portions of ilium. 
The ilio-lumbar ligament1 (Fig. 46), extending from the front 
surface and back of the tip of the transverse processes of the fifth, 
and lower edge and front surface, the transverse processes and 
pedicles of the fourth lumbar vertebra, to the back part of the 
iliac crest; nerves, fourth and fifth lumbar, sympathetic; arteries, 
ilio-lumbar, last lumbar, lateral sacral. 
Describe the sacro-iliac articulations. 
They are amphiarthrodial, formed between the auricular surfaces 
of the ilium and sacrum, and have the following ligaments upon 
each side, in addition to the symphyseal cartilage: 
The anterior sacro-iliac3 (Fig. 47), from the first three pieces of 
the sacrum to the ilium above the great sacro-iliac foramen. 
The posterior sacro-iliac2 (Fig. 46), very strong, extending be- 
tween back of the sacrum and posterior two inches of the iliac 
crest, including the posterior superior spine. 
The oblique, stretching between the third transverse tubercle of 
the sacrum to the posterior superior iliac spine. 
Superior and inferior, bands of fibrous tissue closing in the joint 
above and below. 
The interarticular (interosseous), strongest of all, consists of 
numerous ligamentous hands passing between the contiguous 100 
ESSENTIALS OF HUMAN ANATOMY. 
rough surfaces of the sacrum and ilium; nerves, from posterior 
sacral and lumbo-sacral cords; arteries, gluteal, ilio-lumbar, and 
sacral spinal. 
Describe the ligaments connecting the sacrum and ischiatic 
bones on each side. 
They are the, 
Greater sacro-sciatic8, thin, triangular, passing from posterior 
inferior iliac spine, fourth and fifth transverse sacral tubercles and 
Fig. 46. 
lower lateral margins of sacrum and coccyx, to the inner margin 
of the ischiatic tuberosity. 
The lesser sacro-sciatic4, posterior to former, of same shape, 
stretching between lateral margins of sacrum and coccyx, and the 
spine of the ischium. 
These ligaments convert the two sacro-sciatic notches into the 
greater (by lesser ligament) and lesser (by greater ligament) sacro- 
sciatic foramina, described under iliac and ischiatic bones. 
Describe the sacro-coccygeal articulation. 
Amphiarthrodial, its ligaments are, 
An inter articular fibro-cartilage, like that of a vertebra. 
An anterior sacro-coccygeal, a continuation of the anterior common 
vertebral. THE ARTICULATIONS. 
101 
A posterior sacro-coccygeal, a continuation of the posterior com- 
mon vertebral. 
Inter-cornual and inter-transverse bands, connecting parts of same 
name; nerves, anterior and posterior branches of the fifth sacral 
and coccygeal, posterior division of fourth, and probably second 
and third sacral; arteries, lateral and median sacral. 
Describe the pubic articulation. 
Amphiarthrodial, between the two pubic bones; its ligaments are 
An interosseus fibro-cartilage. 
A supra-pubic, extending along crest of pubes on each side, 
blending with fibro-cartilage. 
A posterior, little more than periosteum. 
An anterior, thick, strong, decussating, attached to contiguous 
portions of body and rami. 
An inferior, or sub-pubic, arched, filling up angle between pubic 
rami; nerves and arteries of no special moment. 
The obturator ligament3 is a fibrous membrane filling the same 
named foramen, except at upper outer part. 
Describe the sterno-clavicular articulation. 
An arthrodial joint formed between the sternal end of the clavicle, 
and the sternum and cartilage of the first rib, having an inter- 
articular fibro-cartilage usually dividing the joint into two distinct 
synovial sacs; its ligaments are, 
A capsular (usually described as anterior, posterior, etc.) passing 
between the articular margins, and firmly connected with the fibro- 
cartilage. 
The inter-clavicular, passing from the posterior superior angle of 
the inner extremity of each clavicle, and attached to the sternum 
between. 
The rhomboid, or costo-clavicular, stretching from the upper 
border of the first costal cartilage to the rhomboid impression of 
the clavicle; nerves, from descendens noni; arteries, contiguous 
muscular branches. 
Describe the acromio-clavicular articulation. 
An arthrodial joint formed by the outer extremity of the clavicle 
and the acromion process of the scapula; it frequently has an inter- 102 
ESSENTIALS OF HUMAN ANATOMY. 
articular fibro-cartilage and two synovial sacs, otherwise there is 
only one sac ; its ligaments are, 
The capsular1, attached to anterior and posterior borders, upper 
and lower surfaces of the acromion and clavicle. 
The coraco-clavicular2, composed of the conoid2, conical, attached 
by apex to base of coracoid process, by base to conoid tubercle of 
clavicle and a line internal to it. 
Trapezoid2, broad and thin, quadrilateral, stretching between 
ridge on upper surface of coracoid to oblique line on under surface 
of clavicle; nerves, supra-scapular, anterior circumflex- arteries, 
supra-scapular, anterior circumflex, acromial thoracic. 
What ligaments bind together the scapular processes ? 
The coraco-acromial3, a triangular flat band, attached by apex to 
summit of acromion, by base all along outer border of coracoid 
process. 
What other ligament of the scapula has not yet been 
described ? 
The transverse4, bridging across the supra-scapular notch. 
Describe the shoulder-jbint. 
An enarthrodial joint formed by head of the humerus and glenoid 
fossa of the scapula. Its synovial membrane is reflected upon the 
tendons of the biceps, subscapular, and infra-spinatus muscles, and 
the joint has numerous bursae in its vicinity, with some of which 
it communicates, notably the subacromial and subscapular; the 
ligaments are, 
CapsulaiA, from the margin of the glenoid fossa above, below, 
and behind, in front extending up on the venter half an inch or 
more, to be attached by its upper half to the anatomical neck of the 
humerus, its lower some distance from the articular margin. 
Coraco-humeral6, a Superadded band stretching from coracoid 
process of scapula to greater humeral tuberosity. 
The glenoid, a dense fibro-cartilage, triangular in cross-section, 
attached to circumference of fossa, deepening the socket, and con- 
tinuous above with the long head of biceps muscle7, which really 
serves as one of the chief ligaments ; nerves, supra-scapular, cir- THE ARTICULATIONS. 
103 
cumflex, subscapulars ; arteries, supra-scapular, subscapular, dor- 
salis scapulae, anterior and posterior circumflex. 
Describe the elbow-joint. 
Ginglymoid, formed by lower end of the humerus, greater sig- 
moid cavity of ulna and head of radius, its ligaments are, 
Fig. 47. 
Fig. 48. 
A capsule1, large, capacious, and usually described as anterior, 
posterior, internal, and external ligaments. 
The anterior segment1 extends from humerus, above articular 
surface and coronoid fossa, to front of coronoid process of ulna 
and neck of radius. 
The posterior segment extends from the back of the humerus, 
from condyle to condyle, and above the olecranon fossa, to be 
attached all around the olecranon process, close to its articular 
margin, and to back of neck of the radius and coronary ligament 
of the same. 104 
ESSENTIALS OF HUMAN ANATOMY. 
The external lateral radiates from lower part of condyle to outer 
side of neck of radius and coronary ligament. 
The internal lateraln, triangular, rises from antero-infcrior aspect 
of inner condyle, aud is attached to inner side of shaft of ulna 
and olecranon process; nerves, musculo-cutaneous, ulnar, median, 
musculo-spiral; arteries, the two profunda arteries, anastomotica 
magna, anterior and posterior ulnar recurrents, posterior interos- 
seous recurrent, and radial recurrent. 
Describe the superior radio-ulnar articulation. 
It is a diarthrosis rotatoria, or trochoides, formed by head of 
radius and lesser sigmoid cavity of ulna, its synovial membrane 
being continuous with that of elbow-joint; its only ligament is the 
Orbicular, surrounding the head of the radius, forming only 
three-fourths of a circle of its fibres, but some, continued 
below the sigmoid cavity, form a complete circle : nerves and arte- 
ries, those of elbow. 
Describe the inferior radio-ulnar articulation. 
A lateral ginglymus, formed by ulnar head and sigmoid cavity of 
radius; its synovial membrane is so loose as to be called the mem- 
brana sacciformis; the ligaments are, 
The triangular fibro-cartilage, attached by apex to fossa at base 
of styloid process of ulna, by its base to margin of radius below 
sigmoid cavity. 
The anterior radio-ulnar stretches between anterior edge of sig- 
moid cavity of radius to rough surface above articular surface of 
ulna. 
The posterior radio-ulnar is similarly attached behind; nerves, 
median and posterior interosseous; arteries, anterior and posterior 
interosseous and carpal arch. 
What other ligaments bind the radius and ulna together ? 
The interosseous membrane*, passing obliquely downward from the 
interosseous ridge of the ulna to that of the radius. 
The oblique4, attached to the tubercle at base of coronoid process 
of ulna above, and below to the lower posterior edge of the 
tubercle of radius; nerves and arteries are from anterior interos- 
seous nerve and artery. THE ARTICULATIONS. 
105 
Describe the wrist-joint. 
Is ginglymoid, with a hinge-movement, not only of flexion and 
extension, but adduction and abduction, a combination of these 
producing circumduction, thus providing a joint with nearly 
every movement of a ball-and-socket joint, without its insecurity. 
It is formed between the radius and triangular fibro-cartilage 
above, and the first row of carpal bones below; its ligaments are, 
An anterior radio-carpal, passing between the radius above the 
articular face and the fibro-cartilage, and the first and second 
rows of carpal bones. 
A posterior radio-carpal, similarly disposed, except that, above, 
it is in addition attached to styloid process of ulna. 
An internal lateral, fan-shaped, passing from styloid process of 
ulna to pisiform, and side and back of cuneiform bones. 
An external lateral, radiating from tip and front of styloid process 
of radius to scaphoid, os magnum, and trapezium; the posterior 
annular ligament also assists the wrist ligaments proper; nerves, 
ulnar, median, and posterior interosseous; arteries, anterior and 
posterior carpal arches, radial and ulnar. 
Describe the carpal articulations. 
Arthrodial, they consist of (1) the joints between the first row ; 
(2) those between the second; and (3) those between the two rows, 
the medio-carpal. 
(1) The pisiform has a separate capsular ligament, with two 
bands connecting it with the unciform and base of fifth metacarpal, 
and a separate synovial membrane; the other three bones of this 
rows are connected by two 
Interosseous ligaments, between scaphoid and lunar, and lunar 
and cuneiform; and 
Two dorsal and two palmar ligaments, binding together the same 
bones. 
(2) The bones (4) of second row have 
Three interosseous ligaments, connecting the os magnum with the 
trapezoid externally, the unciform internally; a third between the 
trapezium and trapezoid ; and 
Three dorsal and three palmar ligaments, passing between the con- 
tiguous bony surfaces. 106 
ESSENTIALS OF HUMAN ANATOMY. 
(3) The two rows are united by 
A dorsal and palmar ligament and two laterals, continuous with 
those of the wrist-joint; the anterior annular ligament, passing from 
the hook of the unciform and from pisiform to the trapezium and 
scaphoid bones, is an important carpal ligament. The synovial 
membrane is common to all the carpal joints, except pisiform-, 
nerves, posterior interosseous, median and ulnar; arteries, anterior 
and posterior carpals of radial and ulnar, carpal of anterior inter- 
osseous, interosseous recurrent, carpal of deep palmar arch, and 
terminal twigs of anterior and posterior'interosseous. 
Describe the carpo-metacarpal articulations. 
That of thumb is arthrodial, and enjoys all movements but rota- 
tion of the metacarpal on its own axis; it possesses a distinct 
synovial sac, and its only ligament is the 
Capsule attached around the articular surfaces of trapezium and 
first metacarpal. 
The other four metacarpals form arthrodial joints with the adja- 
cent carpal bones, with three dorsal ligaments, passing from trape- 
zium, trapezoid, and os magnum to second bone; two ligaments 
from os magnum to third ; two ligaments—one from magnum, the 
other from cuneiform—to fourth ; one ligament connecting the fifth 
metacarpal and unciform. 
One palmar ligament passes from trapezium to second metacarpal; 
one ligament each from trapezium, magnum, and unciform to third; 
one ligament connects unciform and fourth bone; one ligament 
passes from unciform to fifth metacarpal. 
An interosseous ligament connects the contiguous inferior angles 
of os magnum and unciform with adjacent surfaces of third and 
fourth metacarpal hones ; the synovial membrane is that common 
to intercarpal joints, sometimes the joint formed between fourth 
and fifth metacarpals and unciform forms a separate synovial sac; 
nerves and arteries are same as medio-carpal joint. 
Describe the union of the metacarpal bones with one 
another. 
That of the thumb is isolated; the bases of the others are in 
contact, forming arthrodial joints, lined by prolongations of syno- THE ARTICULATIONS. 
107 
vial sac of carpus, and are bound together by palmar, dorsal, and 
interosseous ligaments', a transverse ligament binds together their 
heads. 
Describe the metacarpo-phalangeal and interphalangeal 
articulations. 
Giriglymoid, they are connected by two lateral ligaments, and an 
anterior fibro cartilage, or glenoid ligament, except for thumb, where 
this is replaced by two sesamoid, bones, while behind an expan- 
sion of the extensor tendon and some loose areolar tissue completes 
each little synovial lined capsule; nerves and arteries from digitals; 
the inter-phalangeal joints resemble the metacarpo-phalangeal in 
every respect. 
Describe the hip-joint. 
An enarthrodial, but not so freely moving joint as that of the 
shoulder, it is formed by the head of the femur and the acetabulum 
on the os innominatum ; the ligaments are 
The capsular9, arising near to acetabular margin, and from outer 
surface of the transverse ligament, it is attached at the femur, in 
front to the trochanter major, the spiral line (chiefly formed by 
anterior intertrochanteric linej, and behind, to the neck from one- 
half to two-thirds of an inch from the posterior intertrochanteric 
line; the capsule has a thicker anterior segment, or superadded 
band, called 
The ilio-femoraP, or Y-ligament, arising from the anterior inferior 
iliac spine to be attached to the anterior intertrochanteric line, 
the outer and inner margins so well marked as to seem like distinct 
ligamentous bands. 
The ligamentum teres10, arising by separate heads from each side 
of the cotyloid notch externally, passes beneath the transverse 
ligament covered by the synovial membrane to be attached to a 
depression on the head of the femur. 
Cotyloid, a marginal fibro-cartilage attached all around the 
acetabular margin and upper surface of the transverse ligament, 
deepening the socket. 
Transverse, a band of unyielding ligamentous fibres bridging the 
cotyloid notch, converting it into a foramen; nerves, from anterior 108 
ESSENTIALS OF HUMAN ANATOMY. 
crural, obturator, accessory obturator, nerve to quadratus femoris 
muscle, great sciatic or lower part of sacral plexus; arteries, inter- 
Fig. 49. 
nal and external circumflex, obturator, gluteal, and sciatic. The 
synovial membrane commonly communicates with the bursa beneath 
the ilio-psoas muscle. 
Describe the knee-joint. 
Ginglymoid, formed by condyles of femur, upper surface of tibial 
head, and patella, it has the largest synovial sac of any joint, send- 
ing a prolongation beneath the popliteus muscle and either another 
two or three inches up the front of the femur, or communicating 
with a bursa there placed beneath the quadriceps tendon; the 
bursa between the semi-membranosus and internal head of gas- 
trocnemius, and inner condyle, usually communicates with the 
joint, and often one or more of the remaining bursse near the 
articulation ; its ligaments consist of, 
An anterior or ligamentum patella* (Fig. 51), a continuation of the 
quadriceps tendon attached to the tubercle of the tibia below, 
which, with the fibrous hood formed by the two vasti tendons 
attached to the patellar margins and the oblique lines on the head THE ARTICULATIONS 
109 
of tibia extending upward from the tubercle, cover in the joint in 
front blending with the lateral ligaments. 
The posterior or ligamentum Winslowri8 (Fig. 50), formed of dense, 
interlacing fibres, having incorporated with it part of the semi- 
membranosus tendon7 (Fig. 50), arises close above the femoral 
condyles and intercondyloid notch from one lateral ligament to 
the other, and is fixed to the border of the outer tibial tuberosity, 
the bone below the popliteal notch and the shaft below the inner 
tuberosity. 
The internal lateral6, a strong flat band passing from the depres- 
sion on inner femoral condyle to the inner border and surface of 
Fig. 50. 
Fig. 51. 
shaft of tibia for an inch and a half below the head: it is attached 
to the internal semilunar fibro-cartilage. 
7 he external laterals, two in number: 
The long*, a rounded cord attached above to external tuberosity 
of femur, below to outer part of head of fibula embraced by tendon 
of biceps; 
The short, behind and parallel to above, attached above to lower 
part of outer femoral tuberosity, below to summit of styloid process 
of fibula; it is intimately connected with capsule; all the preced- 
ing ligaments together form a complete 110 
ESSENTIALS OF HUMAN ANATOMY 
Capsular ligament, within which are, 
The internal ligaments; 
The anterior crucial2, from ipner side of depression in front of 
spine of tibia to inner back part of outer condyle of femur; 
The posterior crucial3, from back part of depression behind tibial 
spine and popliteal notch to outer fore part of inner condyle—both 
crucial ligaments are attached to respective extremities of external 
semilunar fibro-cartilage. 
Two semilunar fibro-cartilages6-7 (Fig. 51), attached by extrem- 
ities to the depressions in front and behind the spine of tibia; 
they serve to deepen the sockets for femoral condyles, and are at- 
tached to head of tibia by the coronary ligaments, short bands pass- 
ing between their outer margins and the tibial bead, they are also 
connected to one another, in front, by the small band-like trans- 
verse ligament*-, stretching from front of joint, below patella, to front 
of intercondyloid notch, is the triangular fold of synovial mem- 
brane called the 
Ligamentum mucosum, from whose sides extend upward and out- 
ward to the sides of the patella, the fringe-like folds termed liga- 
menta alaria; nerves, internal and external popliteal, anterior 
crural, obturator; arteries, five articular from popliteal, anastomo- 
tica magna from femoral, recurrent anterior tibial; in addition to 
bursa, already mentioned there is one over patella and its liga- 
ment, one beneath ligamentum patella}, one between inner ham- 
strings and tibial head, and one or more, not always present, 
beneath contiguous tendons. 
Describe the inferior tibio-fibular articulation. 
Arthrodial, formed between facets on fibular head and outer 
tuberosity of tibia, its ligaments are really a capsule, described as, 
Anterior superior tibio-Jibular10 (Fig. 51), directed obliquely up- 
ward and inward from fibula to tibia; 
Posterior superior tibio-fibulce10 (Fig. 50), similarly disposed be- 
hind; the synovial membrane communicates with that of knee in 
twenty-five per cent, of specimens; nerves, from external popliteal; 
arteries, some of those of knee. 
Describe the so-called middle tibio-fibular articulation. 
The contiguous borders of the bones are connected by the inter- THE ARTICULATIONS 
osseous membrane11 (Fig. 51), deficient above for passage of anterior 
tibial artery, below it is perforated by anterior peroneal vessels; its 
fibres pass from fibula upward to tibia. 
Describe the inferior tibio-fibular joint. 
Arthrodial, formed superiorly by the rough surfaces of the con- 
tiguous bones, below by small cartilage-coated surfaces; its syno- 
vial membrane is part of that of the ankle. 
The ligaments are: 
Inferior interosseous, really thicker part of interosseous membrane 
passing between the rough surfaces of the two bones. 
Anterior and posterior inferior tibio fibular, oblique fibrous bands 
binding together the contiguous bony surfaces in front and be- 
hind. 
Transverse, a narrow band passing from external malleolus to 
tibia behind the joint; nerves, those of ankle; arteries, some of 
those of ankle. 
Describe the ankle-joint. 
Ginglymoid, formed by lower end of tibia with its malleolus and 
the external malleolus, and the upper surface and sides of the 
astragalus; its ligaments are the, 
Anterior9 (Fig. 53), connecting the articular margins of the tibia 
and fibula with the rough upper surface of the astragalus. 
Posterior2 (Fig. 52), thin and imperfect, extends between the ex- 
ternal malleolus, back of lower end of tibia and posterior tibio- ESSENTIALS OF HUMAN ANATOMY. 
fibular ligament above, and the posterior surface of astragalus 
from one lateral ligament to the other below. 
Internal lateral6 (Fig. 52), (deltoid) radiates from lower border 
of inner malleolus to astragalus behind and below, in front to 
scaphoid, and passes almost perpendicularly to the os calcis. 
External lateral6,7,8 (Fig. 53), composed of three fasciculi from 
anterior margin, apex, and back of external malleolus, it is 
attached to the astragalus and os calcis: nerves, internal saphen- 
ous and anterior tibial; arteries, anterior and posterior tibials, 
anterior and posterior peroneals. 
Describe the tarsal joints. 
Those of the first row are arthrodial: the astragalus and calcis 
have three ligaments; 
External calcaneo astxagaloid, from outer surface of astragalus to 
same of calcis; 
The posterior calcaneo-astragaloid connects the posterior end of 
astragalus with upper surface of calcis; 
The interosseous, the chief bond, filling up the grooves on the 
under surface of astragalus and upper of os calcis; there are two 
synovial sacs, one posterior, the other anterior continued between 
astragalus and scaphoid: nerves, posterior tibial or plantar; arteries, 
posterior tibial, tarsal, external malleolar (from ant. tibial), and 
terminal twigs of peroneal. 
Those of second row, scaphoid, cuboid, and cuneiforms have, 
Dorsal ligaments, small bands connecting the contiguous bones, 
and, 
Plantar ligaments, similarly disposed ; also four 
Interosseous ligaments, connecting the sides of the scaphoid and 
cuboid, the internal and middle cuneiforms, the middle and ex- 
ternal cuneiforms, the external cuneiform and cuboid; nerves, 
anterior tibial, internal and external plantars; arteries, metatarsal 
and plantars. 
Those between the two rows, or medio-tarsal. (1) The calcaneo- 
scaphoid, arthrodial, has 
The superior\ calcaneo cuboid ligament, connecting the dorsal 
surfaces of calcis and cuboid. 
The internal (interosseous) calcaneo-cuboid, connecting inner THE ARTICULATIONS 
113 
under part of front of calcis with inner postero-inferior angle and 
contiguous part of cuboid. 
The long calcaneo-cuboid (plantar) arises from under surface of 
calcis between posterior tubercles and anterior tubercle, to be 
attached to oblique ridge of cuboid and bases of second, third, 
fourth, and fifth metatarsal bones, completing canal for the long 
peroneal tendon. 
The short plantar arises from the anterior calcaneal tubercle and 
the bone in front, to be attached to the under surface of cuboid 
behind the ridge, except the outer angle; the synovial sac is dis- 
tinct from that of other tarsal joints. 
The (2) astragalo-scaphoid articulation is the only enarthrodial 
(ball-and-socket) joint of tarsus, and communicates with the ante- 
rior calcaneo-astragaloid; its ligaments are, 
The superior calcaneo-scaphoid, dense and thick, extending from 
anterior internal extremity of calcis to under surface of scaphoid. 
The inferior calcaneo-scaphoid, passing obliquely forward from 
neck of astragalus to upper surface of scaphoid ; nerves of medio- 
tarsal joint are, external branch of anterior tibial, sometimes 
musculo-cutaneus or external plantar; arteries, anterior tibial, 
tarsal, metatarsal, or external plantar. 
Describe the tarso-metatarsal articulations. 
Arthrodial, between the three cuneiforms and the cuboid, and 
the bases of the five metatarsals; their ligaments are, 
Dorsal, one for first metatarsal and internal cuneiform; one 
from each cuneiform to second; one from external cuneiform to 
third ; one each from cuboid to fourth and fifth metatarsals. 
Plantar, more irregularly disposed ligamentous fibres. 
Interosseous, one connecting outer extremity of inner cuneiform 
to adjacent angle of second metatarsal; one between outer cunei- 
form and angle of second metatarsal; one connecting outer angle 
of external cuneiform with side of third metatarsal; nerves, ante- 
rior tibial and plantars; arteries, from dorsalis pedis, metatarsal, 
and deep plantar arch. 
Describe the articulations of the metatarsal bones with 
one another. 
Except the first, their bases are bound together by dorsal,plantar, 114 
ESSENTIALS OF HUMAN ANATOMY. 
and interosseous ligaments; the distal extremities are united by the 
transverse metatarsal ligament. 
Describe the metatarso-phalangeal and inter-phalangeal 
articulations. 
They resemble in all respects those of hand, which see. 
How many distinct synovial sacs have the tarsus and 
metatarsus ? 
Six, viz.: (1) Between calcis and astragalus, posterior to inter- 
osseus ligament; (2) in front of same ligament, between calcis and 
astragalus, also between astragalus and scaphoid; (3) between calcis 
and scaphoid ; (4) between scaphoid, cuboid, and cuneiforms, com- 
municating between the middle and external cuneiforms with the 
joints formed between those hones and the bases of the second 
and third metatarsals; (5) between the sides and bases of the fourth 
and fifth metatarsals and the cuboid; (6) between the base of 
first metatarsal and internal cuneiform. 
Muscles and Fasciae. 
Describe a muscle. 
It is a structure connected with bones, cartilages, ligaments, or 
skin, directly or through the medium of a tendon or aponeurosis, 
whose structure is capable of shortening when irritated mechanic- 
ally or by nerve stimulus, this property being called muscular 
contractility or irritability. 
How are muscles divided ? 
According to their form into narrow, broad, penniform (when 
their fibres converge like the plumes of a pen to one side of the 
tendon); bipenniform when so arranged on both sides of a tendon, 
radiated, etc. 
Is there only one variety of muscular tissue ? 
No, there are two, one variety consisting of prismatic fasciculi 
about °f an inch in diameter, marked by transverse striae, 
each bundle surrounded by a sheath or perimysium; each fasciculus 
is formed of a number of fibrillce, yyiznrth of an inch in diameter, MUSCLES AND FASCIA. 
115 
surrounded by a tubular, transparent elastic membranous sarco- 
lemma; every fibril is striated, and consists of a row of minute 
particles, Bowman’s “ sarcous elements-, ” this variety of tissue forms 
the voluntary, striped muscles, or those of animal life, being under 
the control of the will; the involuntary, unstriped, or the muscles of 
organic life, are not under the control of the will, and consist of 
elongated, spindle shaped, flattened, nucleated cells, 5th 
of an inch long, T to broad, and are held together in 
bundles by a cement substance containing a few connective-tissue 
corpuscles, the bundles being further collected into larger fasciculi, 
or flattened bands, bound together by ordinary areolar tissue; this 
kind of muscle is that found forming the contractile coats of the 
stomach, intestines, bladder, arteries, veins, lymphatics, ureters, 
urethra, iris, ciliary body, etc.; when irritated a part, contracts, 
slowly relaxes, while another contiguous portion is contracting, 
which action being continued produces the vermicular (worm-like), 
peristaltic movements of the intestines. The spontaneously coagu- 
lable albuminous substance composing muscle is called myosin-, 
so-called syntonin is a modification produced by chemical agents. 
What are tendons and aponeuroses ? 
Tendons are glistening white cords or bands, of white inelastic 
fibrous tissue, almost without blood- or nerve-supply, and connect 
the muscular tissue with the part to be moved; aponeuroses are 
membranous expansions of the same tissue serving similar pur- 
poses. 
What are the fasciae ? 
They are laminse of fibrous or fibro-areolar tissue investing 
the soft tissues; the superficial fasciae are usually fibro-areolar, 
lie beneath the skin, and are loaded with fat; the deep fasciae 
resemble aponeuroses, are dense and inelastic, ensheathing mus- 
cles, or serving for their attachment, and tend to preserve the 
form of the part, since partitions descend between various muscles 
to become attached to the periosteum of the osseous framework. 
To what are the tendons attached ? 
To the periosteum and perichondrium with which they become 
blended, to the subcutaneous tissue, and to ligaments 116 
ESSENTIALS OF HUMAN ANATOMY. 
What is meant by the origin and insertion of a muscle? 
The origin is the most fixed and central point from which the 
muscle acts; the insertion the movable point to which the muscular 
force is directed; but, in many muscular acts the part usually 
described as the insertion becomes the fixed point and the origin, 
the movable one. 
Do not some muscles have double origins, although single 
insertions ? 
Yes; as the occipito-frontal, digastric, and omo-hyoid. 
Muscles of the Head. 
Describe the origin, insertion, action, and nerve supply of 
the following muscles. 
Occipito-frontalis1: origin, occipital portion, outer two-thirds of 
superior curved line of the occipital bone and mastoid process of 
the temporal; frontal portion, from pyramidalis nasi, corrugator 
supercilii, and orbicularis palpebrarum; insertion, into an aponeu- 
rosis covering the vertex of the skull; action, raises eyebrows and 
transversely wrinkles forehead; nerves, facial, posterior auricular 
branch of same, sometimes the small occipital. 
Attolens aurem*: origin, occipito-frontalis aponeurosis; insertion, 
superior portion of pinna of ear; action, raises pinna; nerve, occip- 
italis minor. 
Atrahens aurem: origin, lateral margin of occipito-frontalis ten- 
don; insertion, a projection on front of helix; action, draws the 
pinna forward and upward; nerve, facial. 
Retrahens aurem5: origin, mastoid portion of temporal; insertion, 
lower part of concha; action, draws ear hack; nerve, posterior 
auricular branch of facial. 
Orbicularis palpebrarum*: origin, internal angular process of the 
frontal, nasal process of superior maxillary bone, and the anterior 
surface and margins of the tendo oculi; insertion, skin of eyelids 
and contiguous portions of forehead, temple, and cheek, blending 
with the occipito-frontal and corrugator supercilii muscles ; action, 
closes eyelids; nerve, facial. MUSCLES OF THE HEAD. 
117 
Corrugator supercilii: origin, inner end of superciliary ridge; 
insertion, under surface of orbicularis palpebrarum; action, draws 
eyebrow downward and inward ; nerve, facial. 
Tensor tarsi (Horner’s muscle): origin, crest of lachrymal bone; 
insertion, by two slips into tarsal cartilages near puncta; action, 
compresses lachrymal sac, and keeps puncta in contact with globe; 
nerve, facial. 
Levator paipebrce superioris8: origin, lesser wing of sphenoid; 
insertion, upper border of superior tarsal cartilage; action, elevates 
upper lid; nerve, third cranial (motor oculi). 
Fig. 54. 
Pyramidalis nasi*: origin, occipito-frontalis; insertion, into com- 
pressor naris; action, depresses inner angle of the eyebrow ; nerve, 
facial. 
Levator labii superioris alceque nasi'': origin, upper part of nasal 
process of superior maxillary bone; insertion, the cartilage of ala 118 
ESSENTIALS OF HUMAN ANATOMY. 
of nose, and into upper lip blending with orbicularis and levator 
labii; action, draws upward the upper lip, and dilates nostril; nerve, 
facial. 
Dilator naris anterior: origin, cartilage of ala; insertion, integu- 
ment near its margin; action, dilates nostril; nerve, facial. 
Dilator naris posterior: origin, margin of nasal notch of superior 
maxilla and the sesamoid cartilages; insertion, skin near margin of 
nostril; action, dilates nostril; nerve, facial. 
Compressor nasi9: origin, above and external to incisive fossa of 
superior maxilla; insertion, fibro-cartilage of nose, and is continu- 
ous with its fellow and the aponeurosis of pyiamidalis nasi; action, 
dilates nostril, by increasing breadth of nose; nerve, facial. 
Compressor narium minor: origin, alar cartilage; insertion, skin 
of tip of nose; action, dilates nostril; nerve, facial. 
Depressor ales nasi: origin, incisive fossa of superior maxilla; 
insertion, septum and back of ala; action, narrows nostril; nerve, 
facial. 
Levator labii superioris9: origin, lower margin of orbit above 
inf'ra-orbital foramen ; insertion, muscular substance of upper lip; 
action, elevates lip ; nerve facial. 
Levator anguli orisw: origin, canine fossa of superior maxilla; 
insertion, angle of mouth; action, elevates angle of mouth; nerve, 
facial. 
Zygomaticus major11: origin, malar bone; insertion, angle of mouth; 
action, elevates angle of lip; nerve, facial. 
Zygomaticus minor10: origin, malar bone anteriorly; insertion, 
angle of mouth ; action, same as zygomaticus major ; nerve, facial. 
Levator labii inferioris {levator menti): origin, incisive fossa of 
lower jaw; insertion, skin of lower lip; action, elevates lower lip; 
nerve, facial. 
Depressor labii inferioris11-19 (quadratus menti): origin, external 
oblique line of lower jaw; insertion, skin of lower lip; action, de- 
presses lower lip ; nerve, facial. 
Depressor anguli orisu: origin, external oblique line of lowTer 
jaw; insertion, angle of mouth; action, depresses angle of mouth; 
nerve, facial. 
Orbicularis oris15: origin, nasal septum and superior and inferior MUSCLES OF THE HEAD. 
119 
maxillary borders by accessory fibres called accessorii orbicularis 
superioris and inferioris, and naso-labialis; insertion, the bucci- 
nator, and other muscles converging to the mouth; action, closes 
mouth; nerve, facial. 
Buccinator13: origin, behind, from the pterygo-maxillary liga- 
ment, above and below, the external surfaces of alveolar processes 
of the three molar teeth; insertion, orbicularis oris; action, com- 
presses cheek; nerve, facial and buccal branch of inferior max- 
illary. 
Risorius (Santorini): origin, fascia over masseter muscle; inser- 
tion, angle of mouth; action, laughing muscle; nerve, facial. 
Masseter12: origin, the superficial portion, from the malar process 
of the superior maxilla and the anterior two-thirds of the lower 
border of the zygomatic arch, the deep portion, from the posterior 
third of the lower border and the inner surface of the zygomatic 
arch ; insertion, upper half of ramus and outer surface of coronoid 
process of lower jaw; action, raises, protracts, and retracts lower 
jaw, a masticatory muscle; nerve, inferior maxillary. 
Temporal: origin, temporal fossa and fascia; insertion, coronoid 
process of lower jaw ; action, raises and retracts lower jaw, a muscle 
of mastication; nerve, inferior maxillary. 
Internal pterygoid: origin, inner surface of external pterygoid 
plate and grooved surface of palate bone, the tuberosity of the 
palate and superior maxillary bones; insertion, lower back part 
of inner side of ramus as high as dental foramen, and angle of 
jaw; action, draws lower jaw forward, a muscle of mastication; 
nerve, inferior maxillary. 
External pterygoid: origin, pterygoid ridge on greater wing of 
sphenoid, the bone included between it and base of pterygoid 
process, the outer surface of external pterygoid plate; insertion, 
depression in front of neck of condyle of lower jaw and inter- 
articular fibro-cartilage ; action, draws jaw forward, a triturating 
masticatory muscle; nerve, inferior maxillary. Sometimes the in- 
ternal maxillary artery passes between the two heads of this muscle; 
sometimes pierces it; often lies below it. 120 
ESSENTIALS OF HUMAN ANATOMY. 
Muscles of the Neck. 
Platysma myoides: origin, clavicle, acromion, and fascia of pec- 
toral, deltoid, and trapezius muscles; insertion, lower jaw beneath 
oblique line, angle of mouth, cellular tissue of face; action, wrinkles 
skin of neck, depresses jaw and angle of lip; nerves, facial, super- 
ficial branches cervical plexus. 
Sterno-cleido-mastoid11 (Fig. 55): origin, upper front part of ster- 
Fig. 55. 
num, inner third upper border of clavicle; insertion, mastoid process 
of temporal and outer two-thirds superior curved line of occipital 
bone; action, acting singly, flexes head sideways, and rotates chin to 
opposite side, both acting flex head on neck, and then on chest; 
nerves, spinal accessory, deep branches of cervical plexus. 
Sterno-hyoidli: origin, riband like, from posterior surface of 
sternum and inner end of clavicle ; insertion, body of hyoid hone; 
action, depresses hyoid bone; nerve, filaments from loop between 
descendens and communicans noni. 
Sterno-ihyroid15: origin, posterior surface of sternum and cartilage 
of first rib; insertion, oblique line on ala of thyroid cartilage ; ac- 
tion, depresses larynx ; nerve same as sterno-hyoid. MUSCLES OF THE NECK. 
121 
Thyro-hyoid16: origin, oblique line of thyroid cartilage; insertion, 
lower border of body and greater cornu of hyoid bone; action, may 
elevate larynx when hyoid is fixed ; nerve, hypoglossal. 
Omo-hyoid18: origin, from upper border of scapula near supra- 
scapular notch, perhaps, also, from transverse ligament; insertion, 
body of hyoid bone, its central tendinous portion being held down 
by a process of deep cervical fascia prolonged down to be attached 
to cartilage of first rib; action, depresses hyoid bone, larynx, and 
draws them backward to one or other side; nerve, from loop between 
descendens and communicans rami. 
Digastric12: origin, has two fleshy bellies with an intermediate 
rounded tendon, the posterior1 is attached to digastric groove of 
mastoid process of temporal, the anterior2 to depression on inner 
side of lower border of jaw near symphysis; insertion, tendon per- 
forates stylo-hyoid, and is held to side of body of hyoid bone by 
aponeurotic loop lined with synovial membrane; action, raises the 
hyoid bone; if this be fixed by its muscles, depresses lower jaw; 
nerves, posterior belly by facial, anterior by mylo-hyoid branch of 
inferior dental. 
Stylo-hyoid4: origin, middle of outer surface of styloid process of 
temporal; insertion, body of hyoid at junction with greater cornu, 
it is perforated by digastric tendon; action, same as digastric; nerve, 
facial. 
Mylo-hyoidb: origin, mylo-hyoid ridge of lower jaw; insertion, body 
of hyoid bone and median raphe; action, same as digastric and 
stylo-hyoid ; nerve, mylo-hyoid branch of inferior dental; it forms 
the muscular floor of the mouth. 
Genio-hyoid6: origin, inferior genial tubercle of lower jaw; in- 
sertion, body of hyoid bone; action, same as mylo-hyoid; nerve, 
hypoglossal. 
Genio-hyo-g/ossus’’: origin, superior genial tubercle of lower jaw; 
insertion, body of hyoid bone, side of pharynx and tongue from base 
to apex ; action, protrudes tongue by posterior and inferior fibres, 
retracts it by anterior fibres, both muscles acting render tongue 
concave from side to side, as in sucking; nerve, hypoglossal. 
Hyo-glossus8: origin, body, lesser, and whole length of greater 
cornu of hyoid bone; insertion, side of tongue; action, draws down 
sides of tongue, making it convex; nerve, hypoglossal, 122 
ESSENTIALS OF HUMAN ANATOMY. 
Stylo-glossus9: origin, near centre of antero-external surface of 
styloid process and stylo-maxillary ligament; insertion, side of 
tongue and hyo-glossus muscle; action, draws tongue upward and 
backward; nerve, hypoglossal. 
Lingualis: origin, forms bulk of tongue lying between hyo-glossus 
and genio-hyo-glossus on each side, running from base to apex, 
some fibres being attached to hyoid bone; action, renders tongue 
convex from before backward; nerve, chorda tympani. 
Palatal Region. 
Levator palati: origin, under surface of apex of petrous portion 
of temporal bone and contiguous portion of cartilaginous Eus- 
tachian tube; insertion, into posterior surface of soft palate; 
action, elevates soft palate; nerve facial through petrosal nerve of 
Vidian. 
Tensor palati: origin, scaphoid fossa, outer side of Eustachian 
tube, spine of sphenoid, edge of tympanic plate; insertion, after 
reflection around hamular process, into forepart of aponeurosis of 
soft palate and under surface of palate bone; action, renders soft 
palate tense; nerve, branch from otic ganglion. 
Azygos uvulae: origin, posterior nasal spine and palatal aponeu- 
rosis ; insertion, uvula; action, raises uvula ; nerve, facial through 
petrosal of Vidian; it is not a single muscle as the name implies. 
Palato-glossus (anterior pillar of fauces): origin, anterior surface 
of palate external to uvula; insertion, side and dorsum of tongue ; 
action, as one of its names implies, constrictor isthmii faucium; 
nerve, palatine branches Meckel’s ganglion. 
Palato-pharyngeus (posterior pillar of fauces): origin, soft palate; 
insertion, posterior border of thyroid cartilage and side of pharynx ; 
action, closes posterior fauces; nerve, same as for palato-glossus. 
Vertebral Region. 
Rectus capitis anticus major: origin, by four tendinous slips from 
anterior tubercles of transverse processes of third, fourth, fifth, 
and sixth cervical vertebrae; insertion, basilar process of occipital 
bone; action, flexes head; nerves, suboccipital, deep branches of 
gervical plexus. MUSCLES OF THE BACK. 
123 
Rectus capitis anticus minor: origin, front of lateral mass of 
atlas and root of its transverse process; insertion, basilar process 
of occipital bone behind preceding muscle; action, flexes head; 
nerves, suboccipital, deep branches of cervical plexus. 
Rectus lateralis: origin, upper surface transverse process of atlas; 
insertion, jugular process of occipital bone; action, draws bead 
laterally when one acts, flexes when both act; nerves, suboccipital, 
deep branches of cervical plexus. 
Long us colli: origin, superior oblique portion from anterior trans- 
verse tubercles of third, fourth, and fifth cervical vertebrae; inser- 
tion, tubercle on anterior arch of atlas; the inferior oblique portion 
arises from bodies of first two or three dorsal vertebrae; insertion, 
transverse processes of fifth and sixth cervical vertebrae; vertical 
portion extends between bodies of upper three dorsal and lower 
three cervical, and those of second, third, and fourth cervical 
vertebrae ; action, flexes and slightly rotates cervical spine; nerves, 
anterior branches from lower cervical nerves. 
Scalenus anticus20 (Fig. 55): origin, tubercle on upper surface of 
first rib; insertion, anterior tubercles of transverse processes of 
third, fourth, fifth, and sixth cervical vertebrae ; action, lateral 
flexion of cervical spine or elevation of ribs ; nerves, anterior 
branches lower cervical nerves. 
Scalenus medius21: origin, upper surface of first rib behind sub- 
clavian groove; insertion, posterior tubercles of transverse pro- 
cesses of lower six cervical vertebrae; action, similar to preceding; 
nerves, anterior branches from lower cervical. 
Scalenus posticus: origin, outer surface of second rib; insertion, 
posterior tubercles of lower two or three cervical vertebrae ; action, 
flexes neck laterally, or elevates second rib; nerves, anterior 
branches from lower cervical. 
Muscles of the Back. 
First layer: 
Trapezius1: origin, inner third of superior curved line of occipital 
bone, ligamentum nuehae, spinous processes of seventh cervical 
and all dorsal vertebrae, and corresponding portion of supra-spinous 
ligament; insertion, outer third posterior border of clavicle, inner 124 
ESSENTIALS OF HUMAN ANATOMY. 
margin of acromion process, the superior lip of crest of spine of 
scapula, and tubercle at its inner extremity; action, one acting 
draws head to its own side, both acting, draw head backward, 
and with head fixed, elevate point of shoulder; middle and lower 
fibres partially rotate scapula on chest; nerves, spinal accessory, 
deep branches of cervical plexus. 
Ligamentum nuchce (a thin band of condensed cellulo-fibrous 
membrane): origin, external occipital protuberance; insertion, 
spinous processes of all cervical vertebrae except atlas; a rudiment 
of strong elastic ligament sustaining head in herbivora, etc. 
Latissimus dorsi*: origin, by an aponeurosis from spinous pro- 
cesses of lower six dorsal vertebrae, those of lumbar and sacral 
vertebrae and supra-spinous ligament, also external lip of iliac 
crest behind external oblique, and from three or four lower ribs; 
insertion, inner lip and bottom of bicipital groove of humerus; 
action, acting on humerus, draws it downward and backward 
while rotating it inward, with fixed arms, raises lower ribs in 
forcible inspiration, assists greater pectorals and abdominal mus- 
cles in drawing trunk forward as when climbing, using crutches, 
etc.; nerve, long subscapular nerve. 
Second layer: 
Levator anguli scapulae10: origin, by three or four tendinous 
slips from posterior tubercles of transverse processes of three or 
four upper cervical vertebrae; insertion, posterior border of scapula 
between superior angle and triangular surface at root of spine; 
action, raises scapular angle; nerves, filaments from fifth cervical 
and from deep branches cervical plexus. 
Rhomboideus minor}1: origin, ligamentum nuchse, and spinous 
processes of seventh cervical and first dorsal vertebrae; insertion, 
margin of triangular surface at root of spine of scapula; action, 
draws inferior angle backward and upward; nerve, fifth cervical. 
Rhomboideus major12: origin, spinous processes of upper four or 
five dorsal vertebrae and supra-spinous ligament; insertion, tendi- 
nous arch stretched from triangular surface at root of spine of 
scapula to inferior angle, the arch being connected with scapular 
border by thin membrane; action, draws inferior angle upward 
and backward; nerve, fifth cervical, muscles of the back. 
125 
Third layer: 
Serratus posticus superior: origin, by thin aponeurosis from 
ligamentum nuehae and spinous processes of seventh cervical and 
Fig. 56. 
two or three upper dorsal vertebrae; insertion, by fleshy digitations 
into upper borders of second, third, fourth, and fifth ribs a little 
beyond their angles; action, elevates ribs during inspiration; 
nerves, external posterior branches of cervical nerves. 
Serratus posticus inferior16: origin, by thin aponeurosis from spi- 
nous processes of last two dorsal and upper two or three lumbar 126 
ESSENTIALS OF HITMAN ANATOMY. 
vertebrae and interspinous ligaments; insertion, by four digitations 
into lower borders of four lower ribs, beyond their angles; action, 
depresses ribs in expiration; nerves, external branches of dorsal 
nerves. 
Splenius capitis et colli1314: origin, tendinous from lower half of 
ligamentum nuchae, the spinous processes of last cervical and of 
upper six dorsal vertebrae, and supraspinous ligament; insertion, 
(S. capitis13) mastoid process and rough surface beneath superior 
curved line of occipital bone (S. colli14), posterior tubercles of trans- 
verse processes of upper three or four cervical vertebrae; action, 
together, draw head directly backward, singly, Ilex head laterally 
and slightly rotate to same side; nerves, external posterior branches 
of cervical nerves. 
Fourth layer: 
Erector spince',2,3, 4,5,6 (Fig. 57): origin, sacro-iliac groove, the 
anterior surface of lumbo-sacral tendon, which is attached intern- 
ally to spines of sacrum, the spinous processes of lumbar and three 
lower dorsal vertebrae and supraspinous ligament externally, the 
back part of inner lip of iliac crest, with the rudimentary trans- 
verse processes of the sacrum and great sacro-sciatic ligament; this 
muscle opposite last rib divides into sacro-lumbalis and longissi- 
mus dorsi muscles; action, maintains spine erect and bends body 
backward; nerves, external posterior branches of lumbar and 
dorsal nerves. 
Sacro-lumbalis1,2: origin, is part of erector spinse; insertion,by 
six or seven tendons into angles of six lower ribs ; action, same as 
erector spinse; nerves, same as erector spinse. 
Musculus accessorius ad sacro-lumbalem : origin, by flattened ten- 
dons from angles of six lower ribs ; insertion, angles of six upper 
ribs; action, same as erector spinse; nerves, those of erector spinse. 
Cervicalis ascendens: origin, angles of four or five upper ribs; 
insertion, posterior tubercles of transverse processes of fourth, fifth, 
and sixth cervical vertebrae; action, keeps neck erect; nerves, ex- 
ternal posterior branches of cervical nerves. 
Longissimus dorsi3: origin, is part of erector spinse; insertion, 
posterior surface of lumbar transverse processes, tubercles at back 
of articular processes, tips of transverse processes of all the dorsal MUSCLES OF THE BACK. 
127 
vertebrae, and from six to eleven ribs between their tubercles and 
angles; action and nerves same as erector spinae. 
Transversalis colli6,9: origin, tendinous from summits of six upper 
dorsal transverse processes; insertion, posterior tubercles of trans- 
verse processes from second to sixth cervical vertebrae; action, keeps 
neck erect; nerves, external pos- 
terior branches of cervical nerves. 
Tracheto-mastoid'1: origin, by ten- 
dons from transverse processes of 
third, fourth, fifth, and sixth dorsal 
vertebrae and articular processes of 
the three or four lower cervical; 
insertion, posterior margin of mas- 
toid process; action, flexes head 
laterally; nerves, external posterior 
branches of cervical nerves. 
Spinalis dorsi: origin, by tendons 
from spinous processes of last two 
dorsal and first two lumbar verte- 
brae ; insertion, by separate tendons 
into spinous processes of from four 
to eight dorsal vertebrae; action, 
erects spine; nerves, external pos- 
terior branches of dorsal nerves. 
Spinalis colli: origin, fifth and 
sixth cervical spinous processes, 
also sometimes those of first and 
second dorsal (this muscle is some- 
times absent); insertion, spinous 
process of axis, occasionally those 
of the two vertebrae below ; action, 
extends cervical spine; nerves, ex- 
ternal posterior branches of cervi- 
cal nerves. 
Complex us8: origin, by seven ten- 
dons from tips of transverse processes of upper three dorsal and 
seventh cervical vertebrae, and articular processes of the three cer- 
vical vertebrae above this; insertion, internally between curved 
lines of occipital bone; action, both draw head backward, singly, 
Fig. 57. 128 
ESSENTIALS OF HUMAN ANATOMY. 
lateral flexion with rotation turning face to opposite side ; nerves, 
internal posterior branches of cervicals, sub-occipital and great 
occipital: (the biventer cervicis being usually blended with this 
muscle will receive no separate description). 
Fifth layer : 
Semispinalis dorsi10: origin, by small tendons from transverse 
processes of from tenth or eleventh to fifth or sixth dorsal verte- 
bra; insertion, by five or six tendons, into spinous processes of 
upper four dorsal and lower two cervical vertebra; action, erects 
spinal column ; nerves, internal posterior branches of dorsal nerves. 
Semispinalis colli11: origin, tendinous and fleshy from upper four 
dorsal transverse processes and articular processes of lower four 
cervicals; insertion, second, third, fourth, and fifth cervical spinous 
processes; action, erects cervical spine; nerves, internal posterior 
branches of cervical nerves. 
Multi fid us spince16: origin, back of sacrum, aponeurosis of erector 
spinae (sacral region); posterior superior iliac spine, posterior sacro- 
iliac ligaments (iliac regions); articulating processes (lumbar and 
cervical regions); transverse processes (dorsal region); insertion, 
lamina and spinous process of third or fourth vertebra above 
(most superficial), second or third above (middle layer); two con- 
tiguous vertebra (deepest layer); keeps spine erect and rotates it; 
nerves, internal posterior branches of cervical, dorsal, lumbar, and 
sacral nerves. 
Rotatores spince (eleven pairs in dorsal region only): origin, each 
from upper back part of transverse process; insertion, lower outer 
part of lamina of vertebra above; action, as name implies; nerves, 
internal posterior dorsal branches. 
Supra-spinales: origin and insertion, cervical spinous processes; 
action, extend cervical spine; nerves, branches of cervical. 
Inter-spinales: origin, variable in number, there are usually six 
cervical pairs commencing between apices of second and third ver- 
tebral spines; two, occasionally three dorsal pairs, between first 
and second, eleventh and twelfth, sometimes second and third ver- 
tebra; four lumbar pairs; sometimes a pair between last dorsal 
and first lumbar, and fifth lumbar and sacrum; action, extend 
spine; nerves, internal posterior nerves of regions. MUSCLES OF THE ABDOMEN. 
129 
Extensor coccygis: origin, last bone of sacrum, or first of coccyx; 
insertion, lower part of coccyx, behind; action, as named ; nerve, 
posterior sacral. 
Intertransversales18: origin and insertion, between anterior and 
posterior tubercles of transverse processes in cervical7, occupy 
intertransverse spaces in other regions (twelve dorsal and four 
lumbar); action, lateral flexion, singly, steady spine when both 
sides act; nerves, posterior spinal branches of each region. 
Rectus capitis posticus major13: origin, spinous process of axis; 
insertion, inferior curved line of occipital bone and surface below; 
rotates head; nerves, suboccipital and great occipital. 
Rectus capitis posticus minor12: origin, tubercle on posterior arch 
of atlas; insertion, rough surface beneath inferior curved line, 
nearly as far as foramen magnum; action, extends head; nerves, 
suboccipital and great occipital. 
Obliquus capitis inferior15: origin, apex of spinous process of 
axis; insertion, apex of transverse process of atlas; action, rotates 
atlas and head; nerves, suboccipital and great occipital. 
Obliquus capitis superior14: origin, tendinous from upper part of 
transverse process of atlas; insertion, between curved lines of occi- 
pital bone external to complexus; action, extends head; nerves, 
suboccipital and great occipital. 
Muscles of the Abdomen. 
External oblique12: origin, by eight fleshy digitations from ex- 
ternal surface and lower borders of the eight inferior ribs; inser- 
tion, anterior half of outer lip of iliac crest, by an aponeurosis 
joining its fellow of opposite side it forms the linea alba, a median 
tendinosis raphe, is connected with ensiform cartilage, symphysis, 
spine, and pectineal line of pubes; it is continuous above with 
aponeurosis of pectoralis major, below it forms a broad infolded 
band, continuous with fascia lata, stretching from anterior iliac 
spine to pubic spine, i. e., Poupart’s ligament, reflected from which 
into the pectineal line, is a portion called Gimbernat’s ligament; 
just above crest of pubis is the triangular external abdominal ring, 
its external border being Poupart’s ligament, its inner, aponeurotic 
fibres, both called pillars of the ring; action, compresses viscera, 130 
ESSENTIALS OF HUMAN ANATOMY. 
flexes thorax on pelvis, or flexes pelvis on thorax, according to 
which is the fixed point, also assists expiration; nerves, lower inter- 
costal. ilio-hypogastric, ilio-inguinal. 
Internal oblique18: origin, fleshy from outer half of Poupart’s 
ligament, anterior two-thirds of middle lip of iliac crest, and pos- 
Fig. 58. 
terior lamella of lumbar fascia; insertion, crest and pectineal line 
of pubis with transversalis muscle —forming conjoined tendon 
part of inner boundary of internal abdominal ring—cartilages of 
lower four ribs, and by an.aponeurosis, which splits for its upper MUSCLES OP THE ABDOMEN. 
131 
three-fourths to enclose the rectus muscle, into linea alba, the ante- 
rior layer blending with aponeurosis of external oblique, the pos- 
terior with that of transversalis muscle, the undivided lower fourth 
passing in front of rectus; action and nerves, same as external 
oblique. 
Transversalis : origin, fleshy from outer third of Poupart’s liga- 
ment, anterior three-fourths of inner lip of iliac crest, inner surface 
of six lower costal cartilages, and by a broad aponeurosis from 
lumbar spinous and transverse processes; insertion, with internal 
oblique as the conjoined tendon into pubic crest and pectineal line, 
by its aponeurosis into linea alba, the upper three-fourths passing 
behind rectus abdominis, the remainder in front of that muscle; 
action and nerves similar to external oblique. 
Lumbar fascia: the vertebral aponeurosis of the transversalis 
divides into an anterior thin layer attached to front of lumbar 
transverse processes and to lower margin of last rib, thus forming 
the ligamentum arcuatum externum; -a middle, stronger layer, 
attached to apices of transverse processes; and a posterior layer 
attached to apices of spinous processes; the quadratus lumborum 
lies between anterior and middle layers, the erector spinae between 
the middle and posterior; the last receives the attachment of the 
internal oblique, and blended with the aponeuroses of the serratus 
posticus inferior and latissimus dorsi, forms the lumbar fascia. 
Rectus abdominis16: origin, by two tendons from pubic crest and 
ligaments over symphysis pubis; insertion, cartilages of fifth, sixth, 
and seventh ribs; this muscle is enclosed in a sheath, the upper 
three-fourths in front formed by the aponeurosis of the external 
oblique and half of that of the internal oblique, behind for the 
same extent of the transversalis aponeurosis with the posterior 
division of that of the internal oblique; at the lower fourth the 
aponeuroses of all these muscles pass in front of the rectus; from 
two to five tendinous intersections traverse the muscle called lineoe 
transversce, while the lineoe semilunares, two curved tendinous lines 
corresponding to the outer border of the recti muscles, extend on 
either side from the eighth costal cartilage to the pubes; action, 
flexes thorax on pelvis, and vice versa, also compresses abdominal 
viscera; nerves, same as external oblique. 
Pyramidalis: origin, tendinous from pubic bone and anterior 132 
ESSENTIALS OF HUMAN ANATOMY. 
pubic ligament, lying in front of, but in same sheath with rectus; 
insertion, linea alba midway between pubes and umbilicus ; action, 
a tensor of linea alba; nerves, same as those of external oblique. 
Quadratus lumborum19 (Fig. 57): origin, ilio-lumbar ligament, 
adjacent two inches of iliac crest, and upper borders of transverse 
processes of third, fourth, and fifth lumbar vertebrae; insertion, 
one-half of lower border of last rib, apices of transverse processes 
of upper four lumbar vertebrae; action, flexes trunk—both acting; 
flexes laterally—one acting; depresses ribs with fixed pelvis and is 
then an expiratory muscle; nerves, anterior branches of lumbar 
nerves. 
Muscles of Thorax. 
External intercostalsn (Fig. 58) (eleven pairs): origin, each from 
outer lip of groove on lower border of each rib from tubercle 
to costal cartilage; insertion, pass obliquely downward and for- 
ward to upper border of rib below for same distance ; action, raise 
and evert ribs in inspiration ; nerves, intercostals. 
Internal intercostals (eleven pairs): origin, each from inner lip 
of groove on lower border of rib reaching from angle to sternum; 
insertion, passing downward and backward to upper border of rib 
below; action, depress and invert the ribs in expiration; nerves, 
intercostals. 
Infracostales: vary in number, most common between lower 
ribs; origin, from inner surface of one rib ; insertion, inner surface 
of first, second, or third rib below, passing obliquely downward 
and backward; action, inspiratory muscles; nerves, intercostals. 
Triangularis sterni: origin, lower part of side of sternum, inner 
surface of ensiform cartilage, and sternal ends of costal cartilages 
of three or four lower true ribs; insertion, by fleshy digitations 
into lower border and inner surfaces of costal cartilages of second, 
third, fourth, and fifth ribs; action, draws down costal cartilages 
in expiration ; nerves, intercostals. 
Levatores costarum: origin (twelve pairs), extremities of dorsal 
transverse processes; insertion, rough surface between tubercle and 
angle of rib below; action, assist external intercostals in raising 
ribs; nerves, intercostals. MUSCLES OF THORAX. 
133 
Diaphragm: origin, arched and convex toward chest, from ensi- 
form cartilage in front, on either side, inner surfaces of cartilages 
and bony portions of lower six or seven ribs, behind, from the 
ligamentum arcuatum externum7 and internum6, and by its crura4,5, 
the left from bodies of second and third, the right, from those of 
second, third, and fourth lumbar vertebrae; insertion, into central 
cordiform tendon1,2,3; action, chief respiratory muscle, increasing 
capacity of chest by becoming flattened when contracted; also aids 
all efforts of expulsion as of feces, etc.; nerves, phrenic and 
phrenic plexus of sympathetic. 
Fig. 59. 
Openings of the Diaphragm : the aorticmedian, in front of verte- 
bral bodies—really behind diaphragm—for aorta, vena azygos 
major, thoracic duct, sometimes left sympathetic nerve ; the oeso- 
phageal9, elliptical, muscular, formed by crura, for oesophagus and 
pneumogastric nerves ; the opening for vena cava}9, highest, quadri- 
lateral bounded by four tendinous bundles meeting at right angles; 
the right crusb, transmits the sympathetic, greater and lesser 
splanchnic nerves; the left crus4, the left greater and lesser 
splanchnic nerves, and vena azygos minor. ESSENTIALS OF HUMAN ANATOMY. 
Muscles of shoulder and arm. 
Pectoralis major1 (Fig. 58): origin, anterior surface inner half of 
clavicle, half the breadth of anterior surface of sternum as low as 
sixth or seventh rib, cartilages of all true ribs except first or seventh, 
or both, and from aponeurosis of external oblique; insertion, fibres 
converge and overlap, the lower being folded back upon them- 
selves, to be attached by a flat tendon to anterior lip of bicipital 
ridge of humerus; action, draws arm forward and inward; with 
fixed arm, an accessory muscle of forced inspiration; nerve, 
anterior thoracic. 
Pectoralis minor6 (Fig. 58): origin, tendinous from upper margin 
and outer surface of third, fourth, and fifth ribs near cartilages, and 
aponeurosis over intercostal muscles; insertion, anterior border 
coracoid process of scapula; action, depresses point of shoulder, 
elevates ribs during inspiration when scapula is fixed; nerves, 
anterior thoracic. 
Subclavius5: origin, tendinous from first costal cartilage; inser- 
tion, groove on middle third of under surface of clavicle; action, 
draws clavicle downward and inward toward the thorax; nerve, 
branch from cord formed by fifth and sixth cervical. 
Serratus magnus4 (Fig. 58): origin, by nine fleshy digitations 
from outer surface and upper border of upper eight ribs (second 
rib has two) and aponeurosis covering upper intercostal spaces; 
insertion, whole length of anterior aspect of posterior border of 
scapula; action, elevates ribs in inspiration with fixed scapula, 
also raises point of shoulder by rotating bone on chest wall; nerve, 
posterior thoracic. 
Deltoid2 (Fig. 58): origin, outer third of anterior border and 
upper surface of clavicle, outer margin and upper surface of acro- 
mion process, and the whole length of lower border of spine of 
scapula; insertion, tendinous into rough prominence on middle of 
outer side of shaft of humerus; action, raises arm to right angle, 
also draws it forward by anterior fibres, or slightly backward by 
posterior portion ; nerve, circumflex. 
Subscapularis4 (Fig. 60): origin, inner two-thirds of subscapular 
fossa; insertion, lesser tuberosity of humerus; action, rotates head 
of humerus inward ; nerve, subscapular. 
Supraspinatusu (Fig. 56): origin, internal two-thirds of same- MUSCLES OF THORAX. 
135 
named fossa and the fascia covering it; insertion, highest facet of 
greater tuberosity of humerus; action, assists deltoid, fixes head of 
humerus in socket; nerve, suprascapular. 
Infraspinatus18 (Fig. 56): origin, internal two-thirds of infra- 
spinous fossa; insertion, tendinous, middle facet of greater tuber- 
osity of humerus; action, rotates head of humerus outward; nerve, 
suprascapular. 
Teres minor19 (Fig. 56): origin, upper two-thirds of dorsal sur- 
face of axillary border of scapula and intermuscular septa; inser- 
tion, lowest facet on greater tuberosity of humerus; action, rotates 
head of humerus outward; nerve, circumflex. 
Teres major20 (Fig. 56): origin, dorsal aspect of inferior angle of 
scapula and intermuscular septum separating from teres minor 
and infraspinatus; insertion, internal lip of 
bicipital groove; action, draws humerus 
downward and backward when raised, also 
rotates it inward; nerve, lower subscapular. 
Coraco-brachialis6 (Fig. 60): origin, fleshy 
from apex of coracoid process of scapula; 
insertion, tendinous, into rough ridge at 
middle of inner side of shaft of humerus; 
action, draws humerus forward and inward, 
also elevates it; nerve, xnusculo-cutaneous, 
which perforates the muscle. 
Biceps flexor cubin'1 (Fig. 60): origin, short 
head, tendinous, in common with coraco- 
brachialis from tip of coracoid process of 
scapula, long head, upper margin of glenoid 
cavity by rounded tendon continuous with 
glenoid ligament; insertion, tendinous into 
back part of tuberosity of radius (a bursa 
is interposed in front), and by a broad apo- 
neurosis opposite elbow, into fascia of fore- 
arm ; action, flexes and supinates forearm, 
renders forearm fascia tense; nerve, muscu- 
lo-cutaneous. 
Brachialis anticus9: origin, lower half of outer and inner surfaces 
of shaft of humerus, embracing insertion of deltoid; insertion, ten- 
Fig. 60. 136 
ESSENTIALS OF HUMAN ANATOMY. 
dinous into anterior surface of coronoid process of ulna; action, 
flexes forearm; nerves, musculo-cutaneous and musculo-spiral. 
Triceps extensor cubiti10: origin, scapular or long head, from 
rough triangular depression below glenoid fossa, the external head 
from posterior surface of shaft between upper part of musculo- 
spiral groove and insertion of teres major, the internal head from 
posterior surface below musculo-spiral groove; insertion, tendi- 
nous, back, upper surface of olecranon process of ulna ; action, ex- 
tends forearm and arm; nerve, musculo spiral. 
Subanconeus: origin, humerus above olecranon fossa; insertion, 
posterior ligament of elbow; action, prevents loose capsule from 
being pinched during extension; nerve, musculo-spiral. 
Muscles of the Forearm. 
Anterior, or flexor and pronator group: All take origin from in- 
ternal condyle, except pronator quadratus. 
Superficial layer. 
Pronator radii teres4 (Fig. 61): origin, double, above, from in- 
ternal condyle and common tendon, fascia of forearm and inter- 
muscular septum, below, from inner side of coronoid process of 
ulna; insertion, tendinous, into rough ridge on middle of outer 
surface of shaft of radius; action, pronates forearm, aids flexion; 
nerve, median. 
Flexor carpii radialis5: origin, internal condyle by common 
tendon, forearm fascia, and intermuscular septa; insertion, tendin- 
ous, into base of index metacarpal; action, flexes wrist, then fore- 
arm ; nerve, median. 
Palmaris longus6: origin, inner condyle by common tendon, 
fascia, and intermuscular septa; insertion, tendinous, into anterior 
annular ligament and palmar fascia; action, tightens palmar 
fascia; nerve, median. 
Flexor carpi ulnaris8: origin, double, by common tendon from 
inner condyle and from inner margin of olecranon by aponeu- 
rosis, and from upper two-tliirds of posterior border of ulna and 
intermuscular septum; insertion, tendinous, into pisiform bone, 
annular ligament and base of little finger metacarpal; action, flexes 
hand on forearm ; then forearm on arm; nerve, ulnar. MUSCLES OF THE FOREARM. 
137 
Flexor sublimis digitorum7 (perforatus) : origin, by three heads, one 
from internal condyle by common tendon and from internal lateral 
ligament and intermuscular septa, a second from inner side of the 
coronoid process of ulna, the third from oblique line of radius; 
insertion, by four tendons, each of which 
splits for the passage of the deep flexor ten- 
dons, each half becoming attached to middle 
of lateral margins of second phalanges ; 
action, flexes fingers, then hand on forearm, 
then forearm on arm; nerve, median. 
Deep layer, 
Flexor profundus digitorum (perforans): ori- 
gin, upper two-thirds of antero-internal sur- 
face of shaft of ulna, inner side of coronoid 
process, by an aponeurosis from upper two- 
thirds of posterior border of ulna and ulnar 
half of interosseous membrane; insertion, 
into bases of last phalanges by four tendons, 
which pass1 between the two slips of flexor 
sublimis tendons ; action, flexes fingers, then 
wrist on forearm; nerves, ulnar and anterior 
interosseous. 
Flexor longus pol/icis: origin, upper two- 
thirds of front of shaft of radius, adjacent 
interosseous membrane, sometimes from base 
of coronoid process; insertion, base of last 
phalanx of thumb; action, flexes last thumb 
phalanx ; nerve, anterior interosseous. 
Pronator quadratus: origin, oblique line on 
lower fourth of anterior surface of ulna, the 
bone below, the anterior border of ulna and 
aponeurosis over muscles; insertion, lower fourth of anterior sur- 
face and external border of radius; action, pronates hand; nerve, 
anterior interosseous. 
Radial Region : all the extensors and supinators arise, at least 
partially, from the external condyle and ridge of the humerus. 
Supinator longus'3: origin, upper two-thirds of external condyloid 
Fig. 61. 138 
ESSENTIALS OF HUMAN ANATOMY. 
ridge and external intermuscular septum; insertion, base of styloid 
process of radius; action, supinates forearm after it has been pro- 
nated, flexes forearm on arm, second in power only to biceps; nerve, 
musculo-spiral. 
Extensor carpi radialis longior5 (Fig. 62): origin, lower third of 
external condyloid ridge and external intermuscular septum ; inser- 
tion, radial side of base of metacarpal bone 
of index finger; action, extends wrist; nerve, 
musculo-spiral. 
Extensor carpi radialis brevior6: origin, ex- 
ternal condyle by common tendon, external 
lateral ligament, the covering aponeurosis 
and the intermuscular septa; insertion, radial 
side of base of metacarpal of middle finger; 
action, extends wrist; nerve, posterior inter- 
osseous. 
Extensor communis digitorum8: origin, ex- 
ternal condyle by common tendon, deep 
fascia and intermuscular septa; insertion, 
second and third phalanges of feach finger 
by three main tendons, one of which sub- 
divides into two; action, extends fingers, 
then hand, finally forearm on arm; nerve, 
posterioi interosseous. 
Extensor minimi digiti9: origin, common 
tendon and intermuscular septa; insertion, 
with tendon of common extensor into second 
and third phalanges of little finger; action, 
extends little finger; nerve, posterior inter- 
osseous. 
Extensor carpi ulnaris10: origin, by common 
tendon from external condyle, middle third 
of posterior border of ulna below aconeus 
and forearm fascia; insertion, ulnar side of 
base of fifth metacarpal; action, extends 
wrist; nerve, posterior interosseous. 
Anconeus: origin, back of outer condyle of humerus; insertion, 
side of olecranon and upper fourth of posterior surface of shaft 
of ulna; action, extends forearm; nerve, musculo-spiral. 
Fig. 62. FASCIiE OF THE HAND. 
Supinator brevisn : origin, external condyle of humerus, external 
lateral ligament and orbicular ligament of radius, oblique line of 
ulna, triangular depression in front of it and aponeurosis covering 
muscle; insertion, back inner part of neck of radius, bicipital 
tuberosity, and oblique line; action, supinates forearm; nerve, 
posterior interosseous which pierces it. 
Extensor ossis metacarpi pollicis13: origin, posterior surface of 
shaft of ulna below anconeus, interosseous ligament, and middle 
third of posterior surface of shaft of radius; insertion, base of 
thumb-metacarpal; action, extends thumb-metacarpal; nerve, 
posterior interosseous. 
Extensor primi internodii pollicis13: origin, posterior surface of 
shaft of radius and interosseous membrane; insertion, base of first 
thumb-phalanx; action, extends phalanx on metacarpal; nerve, 
posterior interosseous. 
Extensor secundi internodii pollicis14: origin, posterior surface of 
shaft of ulna and interosseous membrane below extensor ossis 
metacarpi; insertion, last phalanx of thumb; action, extends 
thumb; nerve, posterior interosseous. 
Extensor indicis: origin, posterior surface of shaft of ulna below 
extensor secundi ; insertion, with tendon of common extensor into 
second and third phalanges of index finger; action, extends index 
finger ; nerve, posterior interosseous. 
Fasciae of the Hand. 
The anterior annular ligament is stretched between pisiform bone 
and unciform process of unciform bone on one side, and the tuber- 
osity of scaphoid and ridge of trapezium on the other ; it is con- 
tinuous with forearm and palmar fascia, and receives the insertion 
of the palmaris longus muscle and partially that of flexor carpi 
radialis, which pierces it; beneath it pass the median nerve and, in 
one synovial sheath, the tendons of the flexor sublimis and pro- 
fundus digitorum and the flexor longus pollicis. 
The post rior annular ligament, continuous with forearm fascia, 
is attached on dorsum internally to ulna, cuneiform, and pisiform 
bones and palmar fascia, externally to ridges on back of and margin 
of radius. Six separate synovial compartments exist for the ex- 140 
ESSENTIALS OF HUMAN ANATOMY. 
tensor tendons; from without inward, they are: (1) outer side of 
styloid process, for extensor ossis metacarpi and extensor primi 
internodii pollicis; (2) behind same process, for extensor carpi radi- 
alis longior and brevior; (3) next for extensor secundi internodii 
pollicis; (4) more internally still, for extensor communis digitorum 
and extensor indicis; (5) opposite interval between radius and 
ulna, for extensor minimi digiti; and (6) back of ulna, for extensor 
carpi ulnaris. 
The palmar fascia9 (Fig. 61), consisting of a central and two lateral 
portions, invests muscles of hand forming their common sheath; the 
central segment is triangular, attached to anterior annular ligament 
above, below dividing into four slips opposite metacarpal heads, each 
slip dividing again to enclose flexor tendons and be inserted on 
sides of first phalanges; strong transverse fibres connect the 
separate processes, and vertical septa, continuous on each side with 
interosseous aponeurosis, separate the middle from lateral palmar 
groups of muscles ; beneath is the superficial palmar arch, median 
and ulnar nerves; the lateral portions of this fascia thinly invest 
the muscles of the thenar and hypothenar eminences. 
Muscles of the Hand. 
Abductor pollicis11 (Fig. 61): origin, ridge of trapezium and an- 
nular ligament; insertion, tendinous into radial side of base of 
first thumb-phalanx; action, draws thumb from median line—i. e., 
abducts it; nerve, median. 
Opponens pollicis: origin, palmar surface of trapezium and an- 
nular ligament; insertion, whole length of radial side of thumb- 
metacarpal ; action, flexes metacarpal; nerve, median. 
Flexor brevis pollicis12 (Fig. 61): origin, by two heads between 
which lies flexor longus pollicis tendon, the external from trape- 
zium and outer two-thirds of annular ligament, the internal from 
trapezoid, os magnum, base of third metacarpal, and sheath of 
tendon of flexor carpi radialis; insertion, sides of base of first 
thumb-phalanx by two tendons each containing a sesamoid bone; 
action, as name implies; nerves, median and ulnar. 
Adductor pollicis: origin, whole palmar length of metacarpal of 
middle finger; insertion, ulnar side of base of first thumb-phalanx MUSCLES OF LOWER EXTREMITY. 
141 
and internal sesamoid bone ; action, draws thumb toward median 
line; nerve, ulnar. 
The preceding muscles form the thenar eminence. 
Palmaris brevis10: origin, tendinous from annular ligament and 
palmar fascia; insertion, skin on inner border of palm ; action, 
wrinkles skin on inner palmar side ; nerve, ulnar. 
Abductor minimi digiti: origin, pisiform bone and expansion of 
tendon of flexor carpi ulnaris; insertion, ulnar side of base of first 
little finger phalanx; action, draws little finger from median line; 
nerve, ulnar. 
Flexor brevis minimi digiti: origin, tip of unciform process and 
annular ligament; insertion, base of first little finger phalanx with 
the abductor; action, flexes little finger; nerve, ulnar. 
Opponens minimi digiti: origin, beneath preceding, from unci- 
form process and annular ligament; insertion, whole length of 
little finger metacarpal; action, flexes fifth metacarpal; nerve, 
ulnar. 
The four preceding muscles form the hypothenar eminence. 
Lumbricales: origin, tendons of deep flexor ; insertion, tendinous 
expansion of extensor communis tendon over dorsum of each 
finger; they are four in number ; action, aid in extending second 
and third phalanges (Duchenne, Hutchinson); nerves, two outer 
by median, two inner by ulnar. 
Dorsal interossei (four in number): origin, by two heads from 
adjacent sides of the metacarpal bones; insertion, into bases of 
first phalanges and aponeurosis of common extensor; action, ex- 
tend second and third phalanges, abduct fingers from middle 
line passing through centre of middle finger; nerve, ulnar. 
Palmar interossei (three in number) : origin, from entire length 
of palmar surfaces of second, fourth, and fifth metacarpal bones ; 
insertion, into bases of first phalanges of same fingers; action, 
adduct (draw) fingers toward middle finger; nerve, ulnar. 
Muscles of Lower Extremity. 
Psoas magnus11 (Fig. 63): origin, sides of bodies, intervertebral 
substances and bases of transverse processes of last dorsal and all 
the lumbar vertebrae; insertion, tendinous, with iliacus, into lesser 142 
ESSENTIALS OF HUMAN ANATOMY 
trochanter; action, flexes thigh on pelvis, or vice versa, also rotates 
femur outward; nerves, anterior branches of lumbar nerves. 
Psoas parvus (often absent): origin, sides of bodies and inter- 
vertebral substance between last dorsal and first lumbar vertebrae; 
insertion, tendinous into ilio-pectineal eminence and iliac fascia; 
action, tensor of iliac fascia; nerves, anterior branches of lumbar 
nerves. 
Iliacus10: origin, iliac fossa and inner margin of iliac crest, ilio- 
lumbar ligament and base of sacrum, anterior superior and inferior 
iliac spines, the notch between them, and capsule of hip-joint; 
insertion, with tendon of psoas magnus into lesser trochanter; 
action, same as psoas magnus; nerve, anterior crural. 
The fascia lata, or deep fascia, is attached above to Poupart’s 
ligament and iliac crest, behind to margins of sacrum and coccyx, 
internally to pubic arch and linea ilio-pectinea, and below to con- 
dyles of femur, tuberosities of tibia, and head of fibula; two strong 
intermuscular septa pass from the inner surface to whole length of 
linea aspera; numerous smaller septa provide separate sheaths for 
each muscle; just below Poupart’s ligament, at the upper inner 
aspect of thigh, is the large oval saphenous opening, formed by the 
margins of the pubic and iliac portions of the fascia lata; Poupart’s 
ligament is an artificial production, being in reality the thickened 
lower portion of the external oblique aponeurosis where the fascia 
lata becomes continuous with it. 
Tensor vaginae femoris4: origin, anterior part of outer lip of iliac 
crest and anterior superior iliac spine; insertion, fascia lata one- 
fourth down thigh, whence fascia is continued down to tibial 
head as the ilio-tibial band; action, tensor of fascia lata; nerve, 
superior gluteal. 
Sartorius5: origin, anterior superior iliac spine and upper half of 
notch below it; insertion, aponeurotic, into upper inner surface of 
shaft of tibia; action, flexes leg upon thigh, thigh upon pelvis, at 
same time drawing limb inward, thus crossing one leg over the 
other; nerve, anterior crural. 
Rectus femoris6: origin, by two tendons, the straight from anterior 
inferior iliac spine, the reflected from groove above acetabulum; 
insertion, patella in common with three next muscles; action, ex- 
tends leg; nerve, anterior crural. MUSCLES OF LOWER EXTREMITY. 
l/astus externus7: origin, tubercle of femur, great trochanter, 
rough line leading thence to linea aspera and whole outer lip of 
linea aspera; insertion, aponeurotic into outer border of patella; 
action, extends leg; nerve, anterior crural. 
Vastus internus and crureuss: origin, line leading from inner side 
of neck of femur to linea aspera and its whole inner lip, internal 
intermuscular septum, internal, anterior, and external surfaces of 
Fig. 63. 
Fig. 64. 
the shaft of femur between the anterior intertrochanteric line and 
the lower fourth of the bone; insertion, aponeurotic, into inner side 144 
ESSENTIALS OP HUMAN ANATOMY. 
of patella, blending with other portions of quadriceps tendon; 
action, extends leg; nerve, anterior crural. The preceding four 
muscles are called the quadriceps extensor6,7,8, whose tendon con- 
tains the patella9, and which is inserted into tubercle of tibia by 
ligamentum patellae. 
Subcrureus: origin, by two heads from lower part of shaft of 
femur; insertion, upper part of synovial pouch of knee; action, 
draws up synovial sac: nerve, anterior crural. 
Gracilis15: origin, aponeurotic from inner margin of ramus of 
pubes and ischium; insertion, upper inner surface of shaft of tibia 
above and behind sartorius; action, flexes leg and adducts thigh ; 
nerve, obturator. 
Pectineus12: origin, linea ilio-pectinea, bone in front of it, and 
tendinous prolongation of Gimbernat’s ligament; insertion, rough 
line passing from lesser trochanter to linea aspera; action, flexes, 
adducts, and rotates thigh outward; nerves, obturator, accessory 
obturator, anterior crural. 
Adductor longusn: origin, tendinous from angle of pubes; inser- 
tion, middle third of linea aspera; action, adducts and flexes thigh; 
nerve, obturator. 
Adductor brevis: origin, outer surface of descending ramus of 
pubes; insertion, upper part of linea aspera; action, adducts and 
flexes thigh; nerve, obturator. 
Adductor magnusli: origin, descending ramus of pubes, ascending 
ramus, outer margin, and under surface of tuberosity of ischium; 
insertion, rough line running from great trochanter to linea aspera, 
whole length of linea aspera, and by a tendon into tubercle above 
inner condyle of femur, between these portions of muscle is an 
angular interval for passage of femoral vessels, the lower orifice of 
Hunter’s canal ; action, adducts and rotates thigh outward ; nerves, 
obturator and great sciatic; the external portion of the muscle 
presents four apertures, the three upper for the perforating arteries, 
the lowest for termination of profunda artery. 
Gluteus maximus2 (Fig. 64): origin, superior curved line of ilium 
and portion of bone and crest just behind it, posterior surface of 
last piece of sacrum, side of coccyx, aponeurosis over multifidus 
spinaj muscle and the greatsacro-sciaticligament; insertion, fascia 
lata and rough line running from great trochanter to linea aspera MUSCLES OF LOWER EXTREMITY 
145 
between vastus externus and adductor magnus; action, maintains 
trunk erect upon thigh, extends, abducts, and rotates thigh out- 
ward ; nerves, small sciatic, and branch from sacral plexus. 
Gluteus medius1 (Fig. 64): origin, outer surface of ilium between 
superior and middle curved lines, outer lip of crest between, and 
gluteal aponeurosis; insertion, 
tendinous into oblique line on 
great trochanter; action, supports 
trunk, the posterior fibres rotate 
thigh outward, the anterior fibres 
rotate thigh inward, it also ab- 
ducts and draws thigh forward; 
nerve, superior gluteal. 
Gluteus minimus8 (Fig. 65): ori- 
gin, outer surface of ilium between 
middle and inferior curved lines 
and margin of sciatic notch; in- 
sertion, anterior border of great 
trochanter; action, draws forward, 
abduct3 and rotates thigh inward, 
aids in maintaining trunk erect; 
nerve, superior gluteal. 
Pyriformis9: origin, by three 
fleshy digitations from bone be- 
tween first, second, third, and 
fourth anterior sacral foramina, 
likewise grooves leading from them, from margin of great sacro- 
sciatic foramen, and great sacro-sciatic ligament; insertion, passing 
out of pelvis by great sacro-sciatic foramen is attached to upper 
border of great trochanter; action, an external rotator of thigh, 
which, when flexed, is abducted by this muscle, also draws pelvis 
forward with fixed femur; nerves, branches of sacral plexus. 
Obturator internus11: origin internal surface of obturator mem- 
brane and tendinous arch for passage of vessels, and inner side of 
obturator foramen; insertion, upper border of great trochanter 
after leaving pelvis by lesser sacro-sciatic foramen; four or five 
tendinous bands pass in the substance of the muscle (Bigelow) 
Fig. 65. 146 
ESSENTIALS OF HUMAN ANATOMY. 
from origin to insertion; action, similar to pyriformis; ner 
branches of sacral plexus. 
Gemellus superior10: origin, spine of ischium; insertion, w 
tendon of obturator internus into upper border of great trochant 
action, rotates thigh outward; nerves, branches of sacral plexus 
Gemellus inferior12: origin, tuberosity of ichium; insertion, gr 
trochanter with obturator internus; action, an external rotatoi 
thigh; nerves, branches of sacral plexus. 
Obturator externus: origin, inner margin of obturator foran 
externally, and inner two-thirds of outer surface of obturator me 
brane; insertion, digital fossa of femur; action, an external rota 
of thigh; nerve, obturator. 
Quadratus femoris13: origin, outer border of tuberosity of ischiu 
insertion, linea quadrati on back of trochanter major; action, < 
ternal rotator of thigh; nerves, branches of sacral plexus. 
Biceps16 (Fig. 65); 4,5 (Fig. 64): origin, by two heads, the lor, 
(Fig 65) from lower inner facet on tuberosity of ischium by tenc 
common to semitendinosus, the short head6 (Fig. 64), from lii 
aspera between adductor magnus and vastus externus, and fr 
intermuscular septum; insertion, outer side of head of fibula, 1 
tendon splitting to embrace external lateral ligament of knee, c 
band extending down as far as outer tuberosity of tibia ; this m 
cle forms the outer hamstring-, action, flexes leg, after which 
slightly rotates it outward ; nerve, great sciatic. 
Semitendinosus6 (Fig. 64),18 (Fig. 65): origin, by common tenc 
with preceding muscle from tuberosity of ischium and adjac< 
aponeurosis; insertion, upper inner surface of shaft of tibia, 
hind sartorius and below gracilis; action, flexes leg on thig 
nerve, great sciatic. 
Semimembranosus' (Fig. 64) : origin, tendinous from upper ou 
facet on tuberosity of ischium ; insertion, groove on inner tub 
osity of tibia; action, flexes leg on thigh, after which it assi 
popliteus in rotating leg inward ; nerve, great sciatic; the tend< 
of sartorius10 (Fig. 64), gracilis8 (Fig. 64), semimembranosus7 (P 
64), and semitendinosus1* (Fig. 66) (enumerated from before ba 
ward), form the inner hamstring. MUSCLES OF THE LEO. 
147 
Muscles of the Leg. 
Tibialis anticus' (Fig. 66): origin, outer tuberosity and upper two- 
thirds of external surface of shaft of tibia, adjacent interosseous 
membrane, deep surface of fascia, and intermuscular septum; in- 
sertion, inner under surface of internal cuneiform bone, base of 
first metatarsal; action, flexes and adducts tarsus; nerve, anterior 
tibial. 
Extensor proprius pollicis': origin, middle two-fourths of anterior 
surface of fibula, and to same extent from interosseous membrane; 
insertion, base of last phalanx of great toe; action, extends great 
toe and, continuing action, flexes tarsus on leg; nerve, anterior 
tibial. 
Extensor longus digitorum4: origin, outer tuberosity of tibia, upper 
three-fourths of anterior surface of fibula, interosseous membrane, 
deep surface of fascia, and intermuscular septa; insertion, divides 
into three tendons, and one subdivides making four tendons, which 
are attached to second and third phalanges of four lesser toes; 
action, extends toes, then flexes tarsus on leg; nerve, anterior tibial. 
Peroneus tertiuss (part of preceding muscle) : origin, lower fourth 
of anterior surface of fibula, interosseous membrane, and inter- 
muscular septum; insertion, upper inner part of base of little toe 
metatarsal; action, same as long extensor; nerve, anterior tibial. 
Gastrocnemius10: origin, by two heads from upper back part of 
condyles of femur and supra-condyloid ridges; insertion, with 
tendons of soleus and plantaris longus forms tendo-Achillis, which 
is inserted into posterior tuberosity of os calcis; action, extends 
foot; nerve, internal popliteal. 
Soleus9,9: origin, tendinous, from back of head of fibula and 
upper third of postero-internal surface of shaft, from oblique line 
of tibia and from middle third of its inner border; insertion, tuber- 
osity of os calcis by tendo-Achillis ; action, extends foot; nerve, 
external popliteal. 
Plantaris : origin, lower part of outer bifurcation of linea aspera 
and posterior ligament of knee-joint; insertion, posterior surface of 
os calcis with tendo-Achillis; action, extends foot; nerve, internal 
popliteal. 148 
ESSENTIALS OF HUMAN ANATOMY. 
Popliteus6 (Fig. 67): origin, depression on outer side of external 
condyle of femur and posterior ligament of knee-joint; insertion, 
inner two-thirds of triangular surface above oblique line of tibia 
posteriorly, and tendinous expansion covering muscle; action, 
flexes leg upon thigh, then rotates tibia inward ; nerve, internal 
popliteal. 
Fig. 66. 
Fig. 67. 
Flexor long us poll ids9 (Fig. 67): origin, lower two-thirds of postero- 
internal surface of shaft of fibula, except its lowest inch, lower 
part of interosseous membrane, intermuscular septum, and fascia 
covering tibialis posticus ; insertion, base of last phalanx of great FASCIA OF THE FOOT. 
149 
toe ; action, flexes great toe, then extends foot; nerve, posterior 
tibial. 
Flexor longus digitorum7 (Fig. 67) (perforans) : origin, posterior 
surface of tibia below oblique line internal to tibialis posticus, ex- 
cept lower three inches, also intermuscular septum, tendon passes 
behind malleolus in groove with tibialis posticus, but in separate 
synovial sheath ; insertion, bases of phalanges of lesser toes by four 
tendons, each passing through a fissure in the tendon of the flexor 
brevis; action, flexes phalanges, then extends foot; nerve, posterior 
tibial. 
Tibialis posticus8 (Fig. 67): origin, by two pointed processes, be- 
tween which pass the anterior tibial vessels, from whole of pos- 
terior surface of interosseus membrane except lowest part, posterior 
surface of tibia, external to flexor longus, between oblique line 
above and middle of external border below, and from upper two- 
thirds of internal surface of fibula; insertion, tuberosity of sca- 
phoid and internal cuneiform bones; action, extends tarsus on leg, 
adducts foot; nerve, posterior tibial. 
Peroneus longus7 (Fig. 66): origin, head and upper two-thirds of 
outer surface of shaft of fibula, deep surface of fascia, and inter- 
muscular septa, passes behind outer malleolus in groove with pero- 
neus brevis8 (Fig. 64), then traverses groove of cuboid; insertion, 
outer side of base of great toe metatarsal and internal cuneiform; 
action, extends foot, then everts it; nerve, musculo-cutaneous. 
Peroneus brevis8 (Fig. 66): origin, lower two-thirds of outer sur- 
face of shaft of fibula, intermuscular septa; insertion, passes with 
preceding muscle behind external malleolus in a groove lined with 
a synovial sheath common to both tendons, to be attached to 
dorsum of base of fifth metatarsal; action, same as peroneus longus; 
nerves, musculo-cutaneous. 
Fasciae of Foot. 
The anterior annular ligament consists of (1) an upper vertical por- 
tion binding down the extensor tendons, attached to lower ends of 
tibia and fibula, continuous above with leg fascia, and containing 
only one synovial sheath situated internally for tendon of anterior 
tibial, the extensor longus digitorum, peroneus tertius, and ex- 150 
ESSENTIALS OF HUMAN ANATOMY. 
tensor proprius pollicis tendons, and anterior tibial vessels and 
nerve passing beneath it without a distinct sheath; and (2) a 
horizontal portion attached externally to upper surface of os calcis, 
and internally to inner malleolus and plantar fascia, containing 
three sheaths, that internal for anterior tibial tendon, the next for 
extensor proprius pollicis tendon, and that most external for ex- 
tensor longus digitorum and peroneus tertius. 
The internal annular ligament is a strong band extending from 
inner malleolus to inner margin of calcis, converting the bony 
grooves on its surface into canals for the flexor tendons and plantar 
vessels; it is continuous with deep fascia of leg, plantar fascia, 
and origin of abductor pollicis muscle. Its three fibro-osseous 
canals transmit, enumerated from within outward, the tendons of 
posterior tibial, flexor longus digitorum, posterior tibial vessels and 
nerve—through broad space beneath ligament—and tendon of 
flexor longus pollicis. 
The external annular ligament stretches between the extremity of 
the outer malleolus to outer surface of calcis, forming a common 
sheath for peroneal tendons. 
The plantar fascia, the densest of all fibrous membranes, consists 
of a central and lateral portions ; the former, thick and narrow be- 
hind, arising from inner tubercle of os calcis, divides into a process 
for every toe, each again splitting opposite metatarso-phalangeal 
joints into two slips—between which pass the flexor tendons—to 
be attached to sides of metatarsal bones and transverse metatarsal 
ligament; two chief and several subordinate intermuscular septa 
are given off, separating the muscular layers ; the outer and inner 
segments are thin, and of no special interest. 
Dorsal region. 
Muscles of the Foot. 
Extensor brevis digitorum: origin, outer surface of os calcis, exter- 
nal calcaneo-astragaloid ligament, and annular ligament; insertion, 
by four tendons, the first into first phalanx of great toe, the other 
three into outer sides of long extensor tendons of second, third, 
and fourth toes; action, accessory to long flexor on four inner toes; 
nerve, anterior tibial, MUSCLES OF THE FOOT. 
151 
Plantar region. First layer. 
Abductor po/licis3 (Fig. 68): origin, inner plantar tubercle of os 
calcis, internal annular ligament, plantar fascia, and intermuscular 
septum; insertion, with, innermost tendon 
of flexor brevis pollieis into inner side of 
base of first great toe phalanx; action, ab- 
ducts great toe; nerve, internal plantar. 
Flexor brevis digitorum5: origin, tendinous 
from inner plantar tubercle of calcis, central 
part of plantar fascia and intermuscular 
septa; insertion, by four tendons for four 
lesser toes, perforated opposite middle of 
first phalanges by tendon of long flexor, be- 
yond the perforation the tendon splitting to 
be inserted into sides of second phalanges; 
action, flexes lesser toes; nerve, internal 
plantar. 
Abductor minimi digits : origin, outer plantar 
tubercle of os calcis, bone in front of both 
tubercles, plantar fascia, and intermuscular 
septum; insertion, with short flexor of little 
toe into outer side of base of first little toe 
phalanx; action, abducts little toe; nerve, 
external plantar. 
Fig. 68. 
Second layer. 
Flexor accessorius : origin, by two heads, from concave surface of 
calcis and calcaneo-scaphoid ligament and os calcis in front of 
outer tubercle, and from plantar ligament; insertion, outer margin 
and upper and under surfaces of tendon of long flexor of toes; 
action, aids long flexor; nerve, external plantar. 
Lumbricales7: origin, tendons of long flexor; insertion, expansion 
of long extensor and bases of first phalanges ; action, accessory to 
flexors; nerves, the two inner lumbricales by internal, the two outer 
by external plantar nerve. 
Third layer. 
Flexor brevis pollicis: origin, inner border of cuboid and contigu- 
ous portion of external cuneiform, and prolongation of posterior 152 
ESSENTIALS OF HUMAN ANATOMY. 
tibial tendon ; insertion, inner and outer side of base of first great 
toe phalanx by two tendons, each containing a sesamoid bone, the 
inner tendon blending with that of the abductor pollicis, the outer 
with that of adductor pollicis; action, flexes great toe ; nerves, in- 
ternal plantar, sometimes external plantar. 
Adductor pollicis: origin, tarsal extremities of second, third, and 
fourth metatarsal bones and sheath of tendon of peroneus longus; 
insertion, with outer portion of the short flexor into outer side of 
base of first phalanx of great toe; action, adducts great toe; nerve, 
external plantar. 
Flexor brevis minimi digiti: origin, base of little toe metatarsal and 
sheath of peroneus longus tendon ; insertion, outer side of base of 
first phalanx of little toe; action, flexes first, extends second 
phalanx; nerve, external plantar. 
Transversus pedis: origin, under surface of head of fifth metatar- 
sal bone and transverse metatarsal ligament; insertion, with adductor 
pollicis into outer side of first phalanges of great toe ; action, ad- 
ducts great toe; nerve, external plantar. 
Fourth layer. 
Dorsal interossei (four): origin, each by two heads from adjacent 
sides metatarsal bones; insertion, tendinous into bases of first pha- 
langes of corresponding toes and aponeurosis of common extensor; 
action, abducts toes from imaginary line passing through centre of 
second metatarsal; nerve, external plantar. 
Plantar interossei (three): origin, base and inner sides of shaft of 
third, fourth, and fifth metatarsal bones; insertion, inner sides of 
bases of phalanges of same toes; action, adduct toes toward a 
line passing through middle of second toe; nerve, external plantar. 
Vascular System. 
What is the pericardium ? 
A closed fibro-serous sac of conical form, its apex surrounding 
the great vessels for about two inches above their origin, its base 
downward, attached to the central tendon of diaphragm. The 
outer fibrous coat is continued as tubular prolongations, lost upon 
the external coats of the roots of all the great vessels except the 
inferior vena cava, and is finally traceable as continuous with the VASCULAR SYSTEM. 
153 
deep layer of the cervical fascia; the serous coat lines the sac, 
forming a parietal layer, is reflected over the heart and great vessels, 
forming a visceral layer; its function is the secretion of a thin fluid 
in sufficient amount to moisten the surfaces, thus lessening friction 
during the heart’s movements. 
Describe the heart. 
It is a hollow, conical muscle, with four distinct cavities, situ- 
ated obliquely between the lungs, the base upward, backward, and 
to the right, the apex11 (Fig. 69) downward, forward, and to the 
left, corresponding to fifth intercostal space, one and a half inches 
below and three-fourths of an inch to the right of the left nipple. 
Give the points upon the exterior of the thorax corre- 
sponding to space occupied by the heart. 
The upper border corresponds to a line drawn across the sternum 
on a level with the lower borders of the second costal cartilages; its 
lower border to a line crossing gladiolus from right side of costo- 
xiphoid joint to apex point above described; the right border 
extending from median line of sternum three inches, its left, one 
and one-half inches; as the lungs partially cover the heart in 
front, the “ area of heart’s dulness ” can be roughly indicated, 
according to Holden, by “ a circle one inch in radius, the centre of 
which is midway between the left nipple and the end of the 
sternum.” 
Give the size and weight of the heart. 
In adults it measures five inches long, three and one-half broad, 
and two and one-half thick; weighs in male ten to twelve ounces, 
in proportion to body 1 to 169; in females, eight to ten ounces, 1 
to 149. 
What are the four cavities of the heart called ? 
The right auricle3 and right ventricle4, the left auricle and left 
ventricle, separated by a longitudinal septum—indicated externally 
in front and behind by the interventricular grooves—dividing the 
heart into lateral halves, the right, or venous heart, the left, or 
arterial heart; a transverse auriculo-ventricular groove on the ex- 
terior corresponds to the division between auricles and ventricles, 154 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the right auricle and the chief points requiring 
study. 
Larger than the left auricle, with a capacity of about two fluid 
ounces, its walls are about one line thick; the venous blood is 
poured in by the superior1 and inferior venae cavae2 and the coro- 
nory sinus; note the following points : 
The sinus, the large quadrangular cavity between the two venae 
cavae; the appendix auriculae, a conical pouch with dentated edge, 
projecting forward to the left over the root of the aorta8; the 
openings of the two venae cavae, also that of the coronary sinus3//, its 
orifice guarded by a semicircular fold of the auricular lining called 
the coronory valve—sometimes at its junction withthegreat coronary 
vein a valve with two unequal segments is found; the tubercle of 
Lower*, a small projection on the right wall directing blood from the 
superior cava toward auriculo-ventricular. opening; the foramina 
Thebesii, the mouth of numerous minute veins returning blood 
from the heart muscle; the semilunar Eustachian valve*' between 
the anterior margin of the inferior vena cava and auriculo-ventri- 
cular opening—it is larger in the foetus, serving to direct the blood 
of the inferior cava through the foramen ovale; the fossa ovalis3', 
an oval depression at the lower part of the septum auricularum, 
the site of the oval foramen in the foetus; the annulus ovalis, the 
prominent margin of fossa ovalis; the musculipectinati, small promi- 
nent muscular columns, running across the inner surface of the 
appendix and adjoining wall of the sinus; the oval auriculo-ven- 
tricular orifice, about one inch in diameter, communicating with 
the right ventricle, its margins formed by a fibrous ring covered 
by the lining membrane, and guarded by the tricuspid valve. 
Describe the right ventricle. 
It is triangular, with apex downward, not quite reaching that of 
the heart, forming with the right auricle the anterior, rather than 
the right side of the heart; its capacity has been variously esti- 
mated at from two to six fluid ounces; it presents the following 
points for examination : 
Above is the conical prolongation called the conus arteriosus, 
from which opens the orifice of the pulmonary artery placed to the 
left of the auriculo-ventricular orifice anteriorly, corresponding to VASCULAR SYSTEM. 
155 
junction of third left costal cartilage with sternum, and is sur- 
rounded by a fibrous ring; the pulmonary semilunar valves guard 
this orifice; the tricuspid valve*,5/,5// formed of three triangular 
segments—the largest on the left side—by a reduplication of the 
lining membrane with interposed fibrous tissue, which are pre- 
vented from being forced into the auricle by the, 
Chordae tendineod>/', fine tendinous cords stretching from (1) the 
columnse carnese to the attached margin, (2) to the centres of the 
leaflets, and (3) to their free margins. 
The columnce carneaeu, three varieties of muscular columns, (1) 
simple ridges, (2) bands attached by both extremities, and (3) three 
or four rnusculipapillares, muscular eminences from which arise the 
chordae tendineae. 
The three pulmonary semilunar valves4, two anterior and one pos- 
terior, formed by a reduplication of the lining membrane with 
interposed fibrous tissue, with their free margins strengthened by a 
bundle of fibrous tissue, whose fibres radiate from a fibro-cartilagi- 
nous nodule—the corpus Arantii—to all parts, except to two narrow 
lunated portions on either side of the nodule, which are forced in 
contact when the valves are closed; above and behind each valve 
is a dilatation, the sinus of Valsalva. 
Describe the left auricle. 
Resembles the right in having a principal cavity or sinus and an 
appendix, but its walls are thicker, measuring about one and one- 
half lines. The following points should be studied: 
The openings of the pulmonary veins, usually four in number, two 
emptying into the right and two into the left side; frequently the 
latter terminate by a common opening. 
The oval auriculo-ventricular opening, surrounded by a fibrous 
ring, smaller than the right; the rnusculi pectinati fewer and smaller 
than on the right side; a depression over site of the fossa ovalis 
of the right auricle. 
Describe the left ventricle. 
Larger and more conical than the right it forms but little of the 
left side, most of the posterior surface and all the apex11 of the 
heart, its walls being three times as thick as those of the right 
ventricle; its inner surface presents for examination. 156 
ESSENTIALS OF HUMAN ANATOMY. 
The circular aortic opening, with the usual fibrous ring, in front 
and to the right of the auriculo-ventricular opening, between them 
intervenes one of the segments of the mitral valve; the aortic 
orifice is opposite the left half of the sternum, on a line with the 
lower border of the third costal cartilage, its mouth being guarded 
by three semilunar valves; the mitral valve, composed of two 
Fig. 69. 
irregular segments—the larger in front—similar to those of the 
tricuspid valve, but larger and thicker, the leaflets being provided 
with chordae tendineae, whose mode of attachment is identical with 
those of the right side. The semilunar aortic valves resemble those 
of the pulmonary artery, but are larger and stronger; sinuses, like 
the sinuses of Valsalva of the pulmonary artery, are found behind 
the aortic valves, THE ARTERIES. 
157 
The columnce carnece are more numerous, but smaller than on the 
right side, while there are only two musculi papillares. 
What is the endocardium? 
The delicate lining membrane of the heart continuous with the 
intima of the great vessels, by its reduplications forming the 
various valves. 
Describe the heart structure. 
It consists of striated anastomosing muscular fibres taking origin 
from the fibrous rings surrounding the aortic, pulmonary, and 
auriculo-ventricular openings, disposed in the auricles in a deep 
layer composed of looped and annular fibres, and a superficial 
transverse layer; in the ventricles numerous layers have been de- 
scribed, the deepest of which run circularly, the more superficial 
spirally, curving round the apex to form the whorl or vortex, those 
fibres from in front curving around to enter posteriorly, and vice 
versa ; the most superficial fibres, especially those behind, pass 
across the septum from one ventricle to the other. 
The Arteries. 
What are the arteries ? 
Cylindrical tubular vessels conveying blood f rom both ventricles 
to all parts of the body; the blood they carry is called arterial-, 
the pulmonary artery arising from the right ventricle conveying 
blood to the lungs, and the four pulmonary veins returning it to 
the left auricle, constitute the lesser or pulmonic circulation, while 
the aorta arising from the left ventricle carrying blood to the 
body generally, and the veins returning it, finally emptying by the 
two cavse into the right auricle, form the greater or systemic circu- 
lation. In their distribution the arteries freely communicate with 
one another, the large branches as well as the small forming what 
are called anastomoses or inosculations, permitting the establish- 
ment of the collateral circulation after obliteration of a main 
artery. 
Describe the structure of the arteries. 
They possess three coats, an (1) internal (serous) or intima\ (2) 158 
ESSENTIALS OF HUMAN ANATOMY. 
a, middle (media), composed in small vessels almost purely of cir- 
cular muscular fibres, in the larger chiefly of yellow elastic tissue; 
this prevents the arteries from collaps- 
ing when cut across; (3) an external 
(adventitia) composed of connective 
tissue. Every vessel, except the intra- 
cranial vessels, is included with its vein 
or veins in a fibro-areolar sheath. 
How are the arteries nourished 
and their calibre regulated ? 
The larger vessels are supplied by 
minute vasa vasorum, bloodvessels dis- 
tributed in a fine network to their ex- 
ternal and middle coats; while intri- 
cate nerve networks (plexuses), chiefly 
derived from the sympathetic with 
branches of the spinal system, supply 
the same coats of the large vessels— 
the smaller are usually supplied only 
with single filaments. 
What are capillaries? 
The intermediate vessels between 
the arteries and veins, disposed in the 
form of a network, of an average di- 
ameter of one-three-tliousandths of an 
inch, formed of a fine transparent layer 
of endQthelial cells united by a cement 
substance. 
Describe the aorta1,2,3, (Fig. 70). 
This, the main trunk of the systemic 
arteries, arises from the upper part of 
the left ventricle, ascends and then 
arches backward to the left over the root of the left lung to descend 
within the thorax on the leftside of the vertebral column, entering 
the abdominal cavity by the aortic openinga through the diaphragm, 
where it terminates opposite the fourth lumbar vertebrae in the 
Fig. 70. THE ARTERIES. 
159 
two common iliac arteries23; the aorta is divided for convenience 
of study into the arch1, thoracic2, and abdominal aorta3, while the 
arch is described as consisting of an ascending, transverse, and de- 
scending portion. The branches of each subdivision are, 
From the arch 
r Two coronary, 
. Innominate4, 
Left common carotid7, 
Left subclavian8. 
Pericardiac, 
Bronchial9, 
GEsophageal10. 
Posterior mediastinal, 
Intercostals11,12, 
From the thoracic aorta 
From the abdominal aorta, Two phrenic13, Two spermaticx20. 
f Gastric15, 
Hepatic17, 
Splenic16, 
Inferior mesenteric21, 
Eight lumbar22. 
Cceliac axis14 
Superior mesenteric18, 
Two supra-renal19, 
Two renal20. 
Sacra media24, 
Describe the coronary arteries. 
The right arises from the aorta above the free margin of the right 
semilunar valve, passes in groove between right auricle and ven- 
tricle to posterior interventricular groove, where* dividing into two 
branches, one continues onward anastomosing with the left coron- 
ary, the other descends along the interventricular groove to apex 
of heart anastomosing with descending branch of left coronary; 
the left coronary, the smaller, arises above the free edge of left 
semilunar valve, passes forward between pulmonary artery and left 
appendix, thence obliquely to anterior interventricular groove, 
where it divides, one branch passing around to join the right 
vessel, the other descending in the groove to anastomose at apex 
with descending branch of right vessel. 
Describe the innominate artery4. 
Arising from the commencement of transverse portion of arch, 
it is from one and a half to two inches long and bifurcates at 
upper border of right sterno-clavicular articulation into right 
common carotid5 and subclavian6, sometimes it sends off a middle 
thyroid branch—occasionally no innominate exists, the right carotid 
and subclavian springing directly from the aorta. 160 
ESSENTIALS OF HUMAN ANATOMY 
Describe the common carotid5,7. 
The right arises opposite right sterno-clavicular joint from in- 
nominate, the left from summit of aortic arch. In the neck their 
course corresponds to a line passing from the sterno-clavicular 
joint t' ” point midway between the mastoid process and angle of 
lower ja ; below, the trachea only separates them, above there is 
a wide interval; a common sheath of deep fascia encloses the in- 
ternal jugular vein, the pneumogastric nerve (posterior to both), 
and artery, enumerated from without inward, while upon the sheath 
lies the descending branch of the ninth cranial nerve (descendens 
noni); the vessel is overlapped for most of its course by the 
anterior margin of the sterno-cleido-mastoid muscle, while about 
its middle it is crossed by the omo-hyoid muscle, the anterior 
jugular, and middle thyroid veins, while above the omo-hyoid 
Fig. 71. 
muscle, the sterno-mastoid artery, and the superior thyroid vein 
cross it; at the lower part of the neck the right internal jugular 
vein diverges from the artery, but the left often crosses the lower 
part of corresponding artery; opposite the upper border of the 
thyroid cartilage, each vessel divides into the internal and external 
carotid. THE ARTERIES. 
161 
Name the branches of the external carotid artery with 
their subdivisions. 
Superior thyroid4, arising below greater cornu of hyoid bone; its 
branches are 
Muscular, Hyoid, Superior laryngeal, 
Superficial descending (sterno-mastoid), Crico-thyroid. 
Lingual arises between thyroid and facial running beneath hyo- 
glossus muscle to under surface of tongue; its branches are 
Hyoid, Dorsalis Linguae, Sublingual, Ranine. 
Facial6 arises just above lingual to cross lower jaw just anterior 
to masseter muscle; its branches are 
Inferior or ascending palatine, 
Tonsillar, 
Submaxillary, 
Submental7, 
Muscular10, 
Inferior labial8, 
Inferior coronary8, 
Superior coronary9. 
Lateralis nasi11, 
Angular12, 
Occipital13 arises posteriorly opposite facial, lies in occipital 
groove of temporal bone; its branches are 
Muscular, Meningeal, Cranial 
’ (distributed 
. over occiput). 
Auricular, Arteria princeps 
Sterno-mastoid. cervicis. 
Posterior auricular16 arises opposite styloid process, ascends 
beneath parotid gland to groove between cartilage of ear and 
mastoid process; its branches are 
Stylo-mastoid, Auricular, Muscular, Parotid. 
Ascending pharyngeal, running between carotid and side of 
pharynx; its branches being 
External 
(muscular and 
nervous), 
Pharyngeal, Meningeal. 
Temporal, the smaller terminal branch, commences in substance 
of parotid gland, crosses root of zygoma, two inches above which it 
divides into anterior24 and posterior25 temporal; its branches are 
Transverse facial20 (Fig. 71), Middle temporal23 (Fig. 71), 
Anterior auricular. 
Internal maxillary1, the larger terminal branch passes inward at 
right angles to the vessel at the inner side of neck of condyle of 
the lower jaw; it is divided into three portions, (1) maxillary, 
(2) pterygoid, and (3) spheno-maxillary. 162 
ESSENTIALS OF HUMAN ANATOMY. 
(1) Anterior tympanic, 
Small meningeal, 
Middle meningeal, 
Inferior dental 
Incisor, 
Mental. 
(2) Deep temporal 
anterior and posterior, 
Pterygoid, 
(3) Alveolar, 
Infra-orbital, 
Posterior or descending 
palatine. 
Masseteric, 
Buccal.* 
Vidian, 
Pterygo-palatine, 
Nasal or spheno-palatine. 
Fig. 72. 
Describe the internal carotid artery. 
It runs in front of the transverse processes of the three upper 
cervical vertebrae in contact with the pharynx and tonsil to the 
carotid canal of temporal bone, enters the skull, passes through 
the cavernous sinus and pierces the dura mater near the anterior 
clinoid processes when it divides into its terminal branches. 
Give its branches. 
Tympanic (deep), from artery in carotid canal, anastomosing with 
tympanic branch of internal maxillary, stylo-mastoid, and Vidian 
arteries. 
Arterice receptaculi, small vessels supplying cavernous and in- 
ferior petrosal sinuses, pituitary body, Gasserian ganglion; one to 
the dura mater anastomosing with the middle meningeal is called 
the anterior meningeal, 
Ophthalmic, from cavernous portion, enters orbit by optic fora- THE ARTERIES. 
163 
men, dividing at the inner angle of the eye into two terminal 
divisions, the frontal and nasal; its branches are 
Lachrymal, 
Supraorbital, 
Posterior ethmoidal, 
Anterior ethmoidal, 
Palpebral, 
Frontal, 
Nasal, 
Muscular, 
Anterior ciliary, 
Short ciliary, 
Long ciliary, 
Arteria centralis retinae. 
Anterior cerebral passes forward in the great longitudinal cere- 
bral fissure, and communicates with its fellow by the anterior com- 
municating artery, a vessel about two lines long. 
Middle cerebral, the largest branch is lodged in the Sylvian fissure 
and divides into an anterior branch topia mater; a middle branch 
to small lobe at outer extremity of fissure; and a posterior branch, 
supplying middle cerebral lobe. 
Anterior choroid, to hippocampus major, corpus fimbriatum, 
velum interpositum, and choroid plexus. 
Posterior communicating runs back to anastomose with posterior 
cerebral, a branch of basilar artery. 
Describe the circle of Willis. 
It consists of a vascular anastomosis at the base of the brain, 
between the branches of the carotids and basiiar artery, whereby 
pressure on, or blocking of any two of the main trunks, will not 
prevent both sides of the brain from receiving a supply of blood. 
Its formation is as follows: The two vertebrals by their junction 
form the basilar, which divides into two posterior cerebral, these latter 
being connected with the back part of the internal carotids on 
each side by a posterior communicating, while the anterior termi- 
nals of the carotid, viz., the anterior cerebral on each side, is con- 
nected in front with its fellow by the short anterior communicating 
artery before mentioned. 
Describe the subclavian. 
On the right side it springs from the innominate, on the left 
directly from the aortic arch. It is divided into three portions, 
viz., that internal to the anterior scalene muscle, that behind the 
muscle, and that external to the scalene, this muscle intervening 
between the artery and subclavian vein ; it ceases to be called sub- 164 
ESSENTIALS OF HUMAN ANATOMY. 
clavian at the lower border of the first rib, being termed axillary. 
All the branches arise from the first portion, except the superior 
intercostal on the right side, which comes from the second portion; 
its branches are, 
The vertebral, which passes through the foramina in cervical 
transverse processes except that of seventh, enters skull through 
foramen magnum, joining its fellow at the lower border of the pons 
Yarolii to form the basilar artery, its branches are, 
Lateral spinal, 
Muscular, 
Anterior spinal, 
Posterior spinal, 
Posterior meningeal, Posterior inferior cerebellar. 
The basilar, formed by the vertebrals, gives off the following 
branches : 
Transverse, Anterior inferior cerebellar, Superior cerebellar, Pos- 
terior cerebral. 
Thyroid axis divides almost at once into 
Inferior thyroid, to same named gland, giving off 
Laryngeal, 
Tracheal, 
Muscular, 
(Esophageal, 
Ascending cervical. 
Suprascapular, chiefly to shoulder-joint and supra-spinous fossa; 
it anastomoses with acromial thoracic, posterior circumflex, the 
posterior and subscapular arteries. 
Transversalis colli, larger than preceding, passes transversely out- 
ward to trapezius, beneath which it divides into the 
Internal mammary arises from under surface of first portion, oppo- 
site thyroid axis, descends upon costal cartilages a short distance 
from the sternum to the sixth interspace, where it divides into 
musculo-phrenic and superior epigastric, the latter anastomosing 
with the deep epigastric of external iliac; the branches are, 
Superficial cervical, Posterior scapular. 
Superior phrenic (comes 
nervi phrenici), 
Mediastinal, 
Pericardiac, 
Sternal. 
Anterior intercostal, 
Perforating, 
Musculo-phrenic, 
Superior epigastric. 
Superior intercostal, its branches are, 
Intercostals, Posterior muscular, Spinal, THE ARTERIES. 
165 
Profunda cervicis, supplying posterior cervical muscles and anas- 
tomosing with arteria princeps cervicis from occipital. 
Describe the axillary. 
It extends from lower border of first rib to lower border of tendons 
of latissimus dorsi and teres major muscles, when it takes the name 
of brachial; its branches are, 
Superior thoracic, supplying pectoral muscles and thoracic wall. 
Acromial thoracic, supplying the deltoid by acromial branches, 
the serratus magnus, and pectorals by thoracic and descending 
branches. 
Long thoracic, to chest muscles and mammary gland. 
Alar thoracic, supplies axillary glands. 
Subscapular, anastomosing with supra- and posterior scapular 
arteries, and giving off" the dorsalis scapulae. 
Posterior circumflex., to deltoid muscle and shoulder-joint; it 
anastomoses with the anterior circumflex, supra-scapular, acromial 
thoracic, and superior profunda arteries. 
Anterior circumflex, to joint and deltoid; it anastomoses with 
posterior circumflex and acromial thoracic arteries. 
Describe the brachial. 
A continuation of axillary, extending from lower border of teres 
major and latissimus dorsi tendons to its bifurcation into radial 
and ulnar, usually just below bend of elbow; the median nerve 
crosses it from without inward about midway in its course; its 
branches enumerated from above downward are, 
Superior profunda, descending arm in musculo-spiral groove, 
giving off posterior articular artery, which anastomoses with the 
interosseous recurrent, posterior ulnar recurrent, and anastomotica 
magna, or inferior profunda, while the terminal twigs of the main 
trunk inosculate with the recurrent radial. 
Nutrient artery, to humerus. 
Inferior profunda, anastomosing with anterior and posterior 
ulnar recurrents and anastomotica magna. 
Anastomotica magna, anastomosing with posterior articular, infe- 
rior profunda, anterior and posterior ulnar recurrents. 
Muscular, to arm muscles. 166 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the radial artery, 
It appears to be a continuation of brachial, but much smaller, 
extending from bifurcation at elbow along radial side of forearm 
to wrist, where, winding beneath the thumb, it passes between the 
two heads of the first dorsal interosseous muscle to palm, there 
inosculating with the deep or communicating branch of the ulnar 
to form 
The deep palmar arch, having as branches three to four palmar 
interossei; sometimes described as also giving off the radialis 
indicis, perforating, and recurrent branches, here credited to main 
vessel. 
The branches of radial are, 
Forearm, 
Radial recurrent, 
Muscular, 
Superficialis voice, 
• Anterior carpal. 
Wrist, 
Posterior carpal, 
Metacarpal, 
Dorsalis pollicis, 
Dorsalis indicis. 
Hand, 
Princeps pollicis, 
Radialis indicis, 
Perforating, 
Interosseous. 
Describe the ulnar. 
Larger than the preceding, it passes from bifurcation obliquely 
inward to middle of forearm, thence runs along its ulnar border, 
across annular ligament to radial side of pisiform bone, curving 
across palm where, either with or without anastomosing with the 
superficialis volse of the radial, it forms the 
Superficial palmar arch, whose branches are the four digitals. 
The branches of the ulnar are, in the 
Forearm, 
Anterior ulnar recurrent, 
Posterior ulnar recurrent, 
Anterior interosseous, 
Posterior interosseous, 
Interosseous 
Muscular. THE ARTERIES. 
167 
Wrist, 
Anterior carpal, 
Posterior carpal. 
Hand, 
Deep, or communicating branch, 
Digitals. 
Describe the thoracic aorta2 (Fig. 73). 
Commencing at left side of lower 
border of fifth dorsal vertebra, it ter- 
minates at the aortic openinga, in dia- 
phragm in front of body of last dorsal 
vertebra; its branches are, 
Pericardiac, variable in number and 
origin, for pericardium. 
Bronchial9, irregular in number and 
origin, usually one right and two left, 
for lung-tissue proper. 
(Esophageal™, commonly numbering 
four to five, anastomosing around the 
gullet with branches of inferior 
thyroid, phrenic, and gastric arteries. 
Posterior mediastinal, numerous and 
small to glands and areolar tissue. 
Intercostals11,lz, usually ten on either 
side, each dividing into an anterior 
and posterior branch, the former sub- 
dividing into two at the angle of the 
ribs, one branch running in groove at 
lower border of rib above, the other 
running along the upper border of the 
rib below, in front both anastomosing 
with anterior intercostal branches of 
the internal mammary, with thoracic 
branches of axillary, with epigastric, 
phrenic, and lumbar arteries; the pos- 
terior division supplies the vertebrae, 
spinal cord, dorsal muscles, and skin. 
Fig. 73. 168 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the abdominal aorta3. 
It commences at the aortic openinga, of the diaphragm in front 
of body of last dorsal vertebrae, whence descending a little to left 
of vertebral column it terminates on the body of the fourth 
lumbar vertebra by dividing into the common iliacs23; its branches 
are, 
Coeliac axis14, arises opposite margin of diaphragm, passes for 
half an inch forward to divide into the 
Gastric15, passing along greater curvature of stomach, anas- 
tomosing with aortic oesophageal, and branches of splenic and 
hepatic arteries. 
Hepaticn, dividing in transverse hepatic fissure into right and 
left branches for same lobes of liver; its branches are, 
Pyloric, 
Gastro-duodenalis, 
Cystic, 
Gastro-epiploica dextra, 
Pancreatico-duodenalis superior, 
whereby it supplies the parts indicated by names of vessels, and 
anastomoses with splenic, gastric, and superior mesenteric arte- 
ries. 
Splenic16, the largest branch, passes behind upper border of 
pancreas to spleen, giving off the 
Pancreaticse parvse, 
Pancreatica magna, 
Gastric (vasa brevis), 
Gastro-epiploica sinistra. 
(One of the phrenics may arise from the coeliac axis.) 
Phrenic13, one on each side (sometimes one from coeliac axis 
instead of aorta) to under surface of diaphragm. 
Superior mesenteric18 comes off about one-quarter inch below 
coeliac axis, arching forward and downward to the left, supplying 
all of small intestine, except first part of duodenum, also ccecum, 
ascending, and transverse colon, giving off, 
Inferior pancreatico-duodenal, 
Yasa intestini tenuis, 
Ileo-colic, 
Colica-dextra, 
Coliea media. 
Inferior mesenteric21, arising from left side of aorta two inches 
above bifurcation, passes down into left iliac fossa and pelvis, sup- 
plying descending colon, sigmoid flexure, and greater part of 
rectum, anastomosing above with the middle colic of superior 
mesenteric; its branches are, THE ARTERIES. 
169 
Colica sinistra, Sigmoid, Superior hemorrhoidal. 
Suprarenal, each arises opposite superior mesenteric to supply 
suprarenal bodies. 
Renal20, spring nearly at right angles from sides of aorta below 
superior mesenteric, the right longer than left; each divides into 
four or five branches before entering hilum of kidney, intervening 
between the renal vein in front, and the ureter behind. 
Spermaticx20 (ovarian in female), spring from front of aorta on 
each side, a little below renals, run behind peritoneum to pass in 
male through abdominal ring to testes, in female between the 
laminae of the broad ligaments to the ovaries, Fallopian tubes, 
uterus, and integument of labium and groin. 
Lumbar22, commonly four on each side corresponding to inter- 
costals, and like them dividing into 
Dorsal branches to vertebrae, spinal cord and back muscles, and 
abdominal branches, passing forward to anastomose with twigs 
from epigastric, internal mammary, intercostals, ilio-lumbar, and 
circumflex iliac. 
Middle sacral2*, springs from bifurcation, descends along middle 
of sacrum and coccyx, sending branches to rectum, lateral sacral 
arteries, etc. 
Describe the common iliac arteries. 
They extend from the aortic bifurcation to left of umbilicus— 
corresponding to a line touching the highest point of iliac crests— 
to divide opposite the intervertebral disk between the last lumbar 
vertebrae and the sacrum, into the internal and external iliac', the 
right vessel is somewhat the longer, both being about two inches 
long, and each at its bifurcation is crossed by the ureter. 
Describe the internal iliac. 
It measures about one and a half inches, arising at point of bifur- 
cation of common iliac, to divide at upper margin of great sacro- 
sciatic foramen into the anterior and posterior trunk; its branches 
are 
Anterior division. 
Superior vesical, part of foetal hypogastric artery ; it supplies vas 
deferens and ureter, as well as bladder. 170 
ESSENTIALS OF HUMAN ANATOMY. 
Middle vesical, usually branch of former to bladder and vesiculae 
seminales. 
Inferior vesical (vaginal in female), arising in common with 
middle hemorrhoidal, and is distributed to base of bladder, pros- 
tate gland, and seminal vesicles. 
Middle hemorrhoidal, supplies rectum. 
• Uterine (in female), anastomosing with ovarian. 
Obturator, passes through obturator canal to thigh, there dividing 
into an internal and external branch, anastomosing with twigs of 
internal circumflex; inside the pelvis its branches are 
Iliac, to same named bone and muscle anastomosing with ilio- 
lumbar ; a vesical, to bladder; and a pubic, inosculating back of 
pubes with epigastric; in two out of every three cases the obtu- 
rator springs from internal iliac, in one case in three and a half 
from epigastric. 
Internal pudic, the smaller terminal of anterior division, is dis- 
tributed to the external organs of generation; giving off the fol- 
lowing branches 
Inferior hemorrhoidal, 
Supei'ficial perineal, 
Transverse perineal. 
Artery of the bulb, 
Artery of the corpus cavernosum, 
Dorsal artery of the penis. 
Sciatic, the larger terminal, supplies muscles on back of pelvis; 
its branches are, 
Muscular (internal), 
Hemorrhoidal, 
Y esical, 
Coccygeal, 
Inferior gluteal, 
Comes nervi ischiadici. 
Muscular (external), 
Articular (hip), 
Posterior division. 
Ilio-lumbar, dividing into an iliac and lumbar branch supplying 
muscular, spinal, and bone branches, anastomosing with gluteal, 
circumflex iliac, external circumflex, and epigastric arteries, etc. 
Lateral sacral, superior and inferior on each side anastomosing 
with gluteal. 
Gluteal, the termination of posterior division, divides into a 
superficial and deep branch, giving off 
Muscular, cutaneous, nutrient (to ilium), and articular branches, 
anastomosing with circumflex iliac and external circumflex 
arteries. THE ARTERIES. 
171 
Describe the external iliac. 
Passes along inner border of psoas muscle from bifurcation of 
common iliac to Poupart’s ligament; a line drawn from left side of 
umbilicus to the midpoint between symphysis pubis and anterior 
superior iliac spine (in females a little nearer the former), indi- 
cates its course; its branches are 
Muscular, Lymphatic (to glands). 
Deep epigastric, usually coming off just above Poupart’s ligament, 
passing between peritoneum and transversalis fascia to pierce the 
lower third of sheath of the rectus abdominis muscle, continuing 
back of which it anastomoses with internal mammary and inferior 
intercostal arteries; its branches are 
Cremasteric, Pubic, Muscular. 
Deep circumflex iliac, arises externally nearly opposite epigastric, 
running along inner side of iliac crest to its middle, there to pierce 
the transversalis muscle; it anastomoses with ilio-lumbar, gluteal, 
lumbar, and epigastric arteries. 
Describe the femoral artery. 
Extending from Poupart’s ligament, where the letters N. A. V. 
indicate its relation with the anterior crural nerve and femoral 
vein—it terminates at the opening in the adductor magnus (com- 
mencement of Hunter’s canal); the upper two thirds of a line 
drawn from the midpoint between the anterior superior iliac spine 
and symphysis pubis to inner side of internal condyle of the femur 
indicates its course. The artery and vein are enclosed in a strong 
fibrous sheath, but separated by a partition from each other, and 
lie very superficially above, in “ Scarpa’s triangle,” bisecting it. 
What is Scarpa’s triangle ? 
It is a space bounded above by Poupart’s ligament, internally 
by the adductor longus, and externally by the sartorius, the floor 
being formed chiefly by the iliac, psoas, pectineus, and long ad- 
ductor muscles, the inner margin of the latter intervening between 
the artery and capsule of the hip-joint. 
The femoral gives off the 
Superficial epigastrici, to inguinal glands, fascia, and skin, anas- 
tomosing with deep epigastric and internal mammary. 172 
ESSENTIALS OF HUMAN ANATOMY. 
Superficial circumflex iliac', to skin of groin, glands, etc., anasto- 
mosing with deep circumflex iliac, gluteal, and external circumflex. 
Fig. 74. 
Fig. 75. THE ARTERIES. 
173 
Superficial externalpudic6, to skin of genitals, anastomosing with 
internal pudic. 
Deep external pudic6, to skin of genitals and perineum, anasto- 
mosing with superficial perineal. 
Profunda femoris1, springing from outer back part of femoral 
from one to two inches below Poupart’s ligament, terminating at 
lower third of thigh by the small fourth perforating artery; it 
gives off 
External8 and Internal circumflex9. Three perforating16. 
Muscularn, chiefly to sartorius and vastus internus. 
Anastomotica magnan, arises just above Hunter’s canal, and 
divides into a superficial (cutaneous), and a deep branch ; anasto- 
mosing with the superior13 internal and external articular, and 
recurrent tibial.14 
Describe the popliteal artery. 
It commences at the opening in the adductor magnus, and pass- 
ing obliquely downward and outward behind the knee-joint, 
divides opposite the lower border of the popliteus muscle into the 
anterior and posterior tibial arteries. Its branches are 
Superior muscular, 
Cutaneus, 
Superior external articular, 
Superior internal articular, 
Azygos articular, 
Inferior internal articular, 
Inferior external articular, 
Inferior muscular or sural. 
These anastomose with the inferior perforating terminal branches 
of profunda, comes nervi ischiadici, anastomotica magna, recur- 
rent tibial and with each other, except the muscular; the azygos 
articular enters hack of joint to supply the synovial membrane 
and intra-articular ligaments. 
Describe the anterior tibial artery. 
Commencing at lower border of popliteus muscle, passing be- 
tween the two heads of the posterior tibial muscle by the defect at 
the upper part of the interosseous membrane, lying upon its anterior 
surface and that of the lowTer third of the tibia, it terminates at 
the front of bend of the ankle in the dorsalis pedis artery, the 
anterior tibial nerve lies in close contact externally; it gives off the 
Recurrent tibial2, Muscular, Internal5 and External4 malleolar. 174 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the dorsalis pedis artery3. 
It extends from front of bend of ankle to back part of first 
interosseous space, where it divides into the 
Dorsalis hallucis’’, supplying the great toe and adjoining side of 
second toe, and the 
Communicating'1, dipping down between heads of first dorsal 
interosseous muscle to reach the sole of foot, and form with ex- 
ternal plantar the plantar arch ; the other branches are the 
Tarsal, arching outward across tarsus. 
Metatarsal*, runs anterior to preceding over bases of metacarpal 
bones, giving off 
Three interossei, from which arise seven digitals. 
Describe the posterior tibial artery. 
It extends as a large vessel obliquely downward from lower border 
of popliteus muscle along tibial side of leg to the midpoint of the 
depression between the inner ankle and heel, where, beneath the 
adductor pollicis muscle it divides into the internal and external 
plantar ; the posterior tibial nerve lies first to its inner side, but 
soon crosses it, to remain close to the outer side; it gives off the 
Peroneal, along back of fibular side of leg, giving off 
Anterior peroneal, piercing interosseous ligament two inches above 
outer malleolus, anastomosing with external malleolar and tarsal 
arteries; it also gives muscular branches and nutrient artery to 
fibula: the posterior tibial also gives off the 
Nutrient (of tibia), largest to any bone. 
Muscular, to posterior leg muscles. 
Communicating, to peroneal, passing transversely across back of 
tibia about two inches above ankle. 
Internal calcanean, several large branches to inner muscles of 
sole, fat and skin of heel, anastomosing with peroneal and internal 
malleolar. 
Describe the internal plantar. 
The smaller terminal of posterior tibial, it runs along inner side 
of foot and great toe. 
Describe the external plantar artery. 
It passes obliquely outward and forward to base of fifth meta- THE ARTERIES. 
175 
tarsal, whence it curves inward to interval between bases of first 
and second metatarsal bones, there anastomosing with the commu- 
nicating branch of the dorsalis pedis, completing the 'plantar arch, 
whose branches, in addition to numerous muscular ones, are, 
Posterior perforating, passing up the three outer interosseous 
spaces to anastomose with the interossei from the metatarsal. 
Four digitals, by division supplying both sides of the three outer 
toes, and the outer side of the second—both sides of the great and 
inner side of the second toe being supplied by the communicating 
branch of dorsalis pedis. 
Describe the pulmonary artery. 
It is a wide vessel conveying venous blood from the right ven- 
tricle to the lungs, about two inches long, and springs, in front of 
the aorta, from left side of the base of the right ventricle, lying 
for most of its course within the pericardium, passing obliquely to 
the left, upward and backward, dividing at the under surface of 
the aortic arch into a right and left pulmonary artery, the former 
the longer; each vessel passes horizontally outward to its respective 
lung, where it divides into two main branches, one of those of the 
right subdividing to supply the third lobe; these vessels subdivide 
to terminate in the pulmonary capillaries. 
Describe the collateral circulation after ligature of the 
common carotid. 
The chief communications are between superior and inferior 
thyroids, the profunda cervicis and princeps cervicis of the occi- 
pital, the vertebral taking the place-of the internal carotid within 
the cranium. (The student must remember that while all the 
anastomosing vessels coming off above and below the site of liga- 
ture enlarge, and should, therefore, be carefully impressed upon 
the mind where enumerated in the preceding pages, yet the blood, 
by dissection, has been found to pass chiefly by the vessels men- 
tioned under each caption.) 
After ligature of the subclavian. 
Between the supra-scapular and posterior scapular with sub- 
scapular, the internal mammary and the long and short thoracic 
and subscapular. 176 
ESSENTIALS OF HUMAN ANATOMY. 
After ligature of axillary. 
If below acromial thoracic, chiefly between the subscapular and 
other scapular arteries of subclavian, and long thoracic, through 
intercostals with internal mammary; if below subscapular, the 
posterior circumflex anastomosing with supra-scapular and acro- 
mial thoracic, and inosculations between the subscapular and 
superior profunda. 
After ligature of brachial. 
(1) Upper third, by anastomoses between circumflex and sub- 
scapular and superior profunda; (2) below the profunda arteries, 
by branches of the profundm anastomosing with recurrent ulnar, 
radial, and interosseous. 
When thoracic aorta is obliterated. 
The internal mammary anastomosing with intercostals; phrenic, 
by musculo-phrenic and comes nervi phrenici and deep epigas- 
tric , superior intercostal and first aortic intercostal; inferior 
thyroid with first aortic intercostal; transversalis colli with pos- 
terior branches of intercostals ; axillary and subclavian branches 
to side of chest with lateral branches of intercostals. 
When abdominal aorta is tied. 
The deep epigastric communicating with the internal mammary, 
the intercommunications of superior and inferior mesenteric, or 
the latter with the internal pudic, and the anastomoses of the 
lumbar with branches of internal iliac. 
After common iliac is tied. 
The anastomosis of hemorrhoidal branches of internal iliac 
with superior hemorrhoidal from inferior mesenteric, the inoscu- 
lations of the uterine and ovarian, and of vesieals of opposite 
sides, that of lateral sacral with sacra media, of epigastric with 
internal mammary, intercostal and lumbar, of ilio-lumbar with 
last lumbar, of obturators with one another and deep epigastric, 
of gluteal with posterior sacral branches. 
After internal iliac is tied. 
Same as above, except obturator also communicates with internal THE VEINS. 
177 
circumflex, the circumflex and perforating branches of femoral 
with sciatic, and the circumflex iliac with ilio-lumbar and gluteal. 
After external iliac is tied. 
The anastomoses between the ilio-iumbar and circumflex iliac ; 
the gluteal and external circumflex; the obturator and internal 
circumflex; the sciatic with superior perforating and circumflexes; 
the internal pudic with external pudic and internal circumflex. 
After common femoral is tied. 
Anastomoses of gluteal and circumflex iliac with external cir- 
cumflex ; obturator and sciatic with internal circumflex; ilio- 
lumbar with external circumflex; comes nervi ischiadici with 
surals. 
After superficial femoral is tied 
Branches from profunda anastomosing with superior and inferior 
articulars of knee, anastomotica magna, surals, and origins of 
anterior and posterior tibial. 
(The popliteal is never tied except for wound, when the articu- 
lar arteries, anastomotica magna, recurrent tibial, perforating 
branches, and surals would convey the blood.) 
The Veins. 
Describe the veins. 
They are vessels returning venous blood—i. e., blood surcharged 
with carbonic acid, to the heart, and have the same coats as arte- 
ries, but not so thick, especially the middle, in consequence col- 
lapsing when divided. One set of veins only carries other than 
venous blood, viz., the pulmonary, conveying arterial blood from 
the lungs to the left auricle. Certain of the veins, usually the 
superficial, have their lining membrane forming semilunar redupli- 
cations or valves, arranged in pairs opposite one another, which 
prevent any reflux of blood. The large arteries are accompanied 
by deep veins of the same name, generally included in the same 
sheath, while such vessels as the brachial, radial, ulnar, etc., have 
two veins each, called vence comites. The superficial veins run be- 
tween the layers of the superficial fascia, terminating in the deep 178 
ESSENTIALS OE HUMAN ANATOMY. 
veins, and are not usually accompanied by arteries. All veins freely 
anastomose, and even those dignified with special names have 
very irregular origins and distributions. 
What are sinuses? 
Venous channels, found only within the skull, formed by a sepa- 
ration of the layers of the dura mater, lined with endothelium con- 
tinuous with that of the veins. 
How are the veins classed ? 
As belonging to the pulmonary, systemic, or portal systems, the 
latter an appendage of the systemic. 
Name the principal veins which have no valves. 
The venae cavae, hepatic, portal, renal, uterine, ovarian, cerebral, 
spinal, and pulmonary. 
Name the veins of the head and neck, 
(1) Those of the exterior : 
Facial, 
Temporal, 
Internal maxillary, 
Temporo-maxillary, 
Posterior auricular, 
Occipital. 
(2) Those which return the blood from head and face: 
External j ugular, 
Posterior external jugular, 
Anterior j ugular, 
Internal jugular, 
(3) Veins of diploe and cranium: 
Vertebral. 
Veins of diploe, 
Cerebellar, 
Cerebral, 
Ventricular, or venae galenae. 
Name the cerebral sinuses. 
Superior longitudinal, 
Inferior longitudinal, 
Occipital (2), 
Circular, 
Superior petrosal, 
Straight sinus, 
Lateral sinuses (2), 
Cavernous (2), 
Transverse, 
Inferior petrosal. 
How is the internal jugular7 (Fig. 76) formed? 
By the junction of the lateral and inferior petrosal sinuses just 
outside jugular foramen ; at base of neck the internal jugular 
unites with subclavian vein to form the innominate vein—at, or THE VEINS. 
179 
above the junction is a pair of valves ; into the jugular empty 
the facial, lingual, pharyngeal, superior and middle thyroid, and 
sometimes occipital veins. 
Where do the following veins empty ? 
The external jugular*; into subclavian vein external to internal 
jugular; the posterior external jugular, into internal jugular; the 
anterior jugular, into termination of external jugular or the sub- 
clavian vein; the vertebral, descends through vertebral foramina 
in transverse processes of cervical vertebrae to empty into back of 
innominate vein, valves guarding the orifice. 
Describe the veins of the upper extremity. 
They consist of superficial and deep, the latter being the venae 
comites of the arteries; commencing as digitals these empty into 
the interossei, these into palmar until the deep radial and ulnar 
are formed, which, uniting, form the so-called brachial vein, really 
consisting of two venae comites with transverse anastomoses. The 
superficial veins running in the superficial fascia are called 
Ra'llal 
Median cephalic 
Cephalic 
Median 
Median basilic 
Brack ial 
Axillary. 
, , j 
Anterior and 
Posterior ulnar 
Basilic 
Describe the axillary vein. 
It is a continuation of brachial and basilic, receiving veins of 
corresponding names with the arteries of the axilla, and is con- 
tinued beneath the clavicle under the name of the subclavian vein9; 
it has valves opposite lower border of subscapular muscle, also at 
mouths of cephalic and subscapular veins. 
Describe the subclavian vein9. 
It extends from lower border of first rib to back of sterno- 
clavicular joint, there uniting with internal jugular to form the 
vena innominata—the subclavian vein lies in front of the artery 
with the anterior scalene muscle interposed at its second part; its 
branches are, the external and anterior jugular and branch of 
cephalic; on right side the right lymphatic duct empties at the 180 
ESSENTIALS OF HUMAN ANATOMY. 
junction of the axillary and internal jugular veins, and at the 
same point on the left side the thoracic duct. 
How are the venae innominatae5,6 formed? 
Each by the subclavian and internal jugular, which unite just 
below the first costal cartilage to form the superior vena cava4; 
the right innominate is about one and a 
half inches long, receiving blood by right 
vertebral, internal mammary, inferior 
thyroid, and superior intercostal veins; 
the left vein is larger and about three 
inches long; the left vertebral, internal 
mammary, inferior thyroid, superior inter- 
costal, and occasionally some thymic and 
pericardiac veins empty into it. 
Describe the superior vena cava4. 
It measures from two and a half to 
three inches and is formed by the union 
of the two innominate veins5,6, is half 
covered by the pericardium and enters 
upper part of right auricle; it returns the 
blood of the upper half of body and re- 
ceives the vena azygos major and small 
mediastinal and pericardiac veins. 
Describe the azygos veins. 
They connect the superior and inferior 
venae cavae, taking the place of those 
vessels in that part of the chest occupied 
by the heart. 
The right azygos10 commences opposite 
first and second lumbar vertebra1 by a 
branch from right lumbar or renal vein, 
or from inferior vena cava, enters thorax 
by aortic opening, arches over root of right lung to empty into 
superior cava, receiving in its course the nine or ten right lower 
intercostal veins, the vena azygos minor, oesophageal, medias- 
Fig. 76. THE VEINS. 
181 
tinal, vertebral, and right bronchial veins, also at times it is con- 
nected with right superior intercostal vein. 
The left lower azygos11 (vena azygos minor) commences by a 
branch from left lumbar or renal vein, enters thorax through left 
crus of diaphragm, passes across from the left side of vertebral 
column at sixth or seventh dorsal vertebra to enter the right 
azygos vein, receiving veins from four or five lower intercostal 
spaces; also mediastinal and oesophageal branches. 
The left upper azygos12 is formed by veins, usually two to three, 
from the intercostal spaces between left superior intercostal and 
highest branch of left lower azygos, and empties into right azygos 
or left lower azygos; it is sometimes absent, its place being taken 
by left superior intercostal. 
Name the other principal veins of base of the neck and of 
the thorax. 
Internal mammary, 
Inferior thyroid, 
Intercostals, 
Mediastinal, 
Pericardiac, 
Bronchial. 
Briefly describe the spinal veins. 
They are the dorsi-spinal on the exterior of the spinal column, 
forming plexuses around vertebral spines, laminae, and processes, 
emptying into intercostal, lumbar, and sacral veins respectively. 
The meningo-rachidian, lying between vertebrae and theca spinalis 
forming plexuses, one running along the posterior surfaces of ver- 
tebral bodies forming the anterior longitudinal veins receiving the 
venae basis vertebrarum, the other on the inner surface of the lami- 
nae, the posterior longitudinal veins, both extending the whole length 
of the spinal canal; the posterior emptying into dorsi-spinal, the 
anterior into vertebral, intercostal, and sacral veins, respectively. 
The venae basis vertebrarum, in vertebral bodies, empty into an- 
terior longitudinal. 
The medulli-spinal, those of the cord itself, forming a minute 
plexus over cord between the pia mater and arachnoid, near base 
of skull converging to form two or three trunks terminating in the 
inferior cerebellar veins or petrosal sinuses, 182 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the chief veins of the lower extremity. 
They are deep and superficial, the former commence as venae 
comites of digitals, Avhich form the interossei, these the anterior 
and posterior tibial and peroneal accompanying same named 
arteries, which uniting, form the popliteal, in the thigh to be 
called the femoral, being joined by profunda femoris and internal 
saphenous veins, which again changes its name to external iliac 
above Poupart’s ligament; into external iliac empty the epigastric 
and circumflex iliac veins. 
The superficial veins are the 
Internal or long saphenous, commencing on inner side of dorsum 
of foot, running up on inside of leg and thigh to enter femoral 
vein after passing through the saphenous opening of fascia lata; 
its branches are 
Cutaneous, 
Superficial epigastric, 
Superficial circumflex iliac, 
Commun icating, 
Pudic. 
External or short saphenous, commences at outer side of dorsum 
of foot, passes behind the external malleolus, up the middle of leg 
posteriorly to empty into popliteal vein between heads of gastroc- 
nemius. 
Describe the internal iliac vein. 
It is formed by the venae comites of all branches of external iliac 
artery except the umbilical, and unites opposite sacro-iliac articu- 
lation with external iliac vein to form the common iliac vein ; it 
receives the following veins, 
Gluteal, 
Sciatic, 
Internal pudic, 
Obturator, 
Hemorrhoidal, 
Vesico-prostatic 
Uterine and vaginal, 
Plexuses, in female, 
Plexuses, in male, 
Dorsal vein of penis. 
Describe the common iliac veins. 
Formed by the junction of the external and internal iliac veins, 
and receiving the ilio-lumbar, occasionally the lateral sacral, and 
the left iliac the middle sacral vein, they unite at an angle upon 
the intervertebral substance between the fourth and fifth lumbar 
vertebrae to form the inferior vena cava, THE VEINS. 
183 
Describe the inferior vena cava1. 
It runs upward from junction of the two common iliacs, along 
the right side of the aorta, pierces the central tendon of dia- 
phraghm, and terminates at back of right auricle, being partially 
covered by serous layer of the pericardium; it returns the blood 
from all parts below the diaphragm, and receives the following 
branches, 
Lumbar, 
R'ujht spermatic, 
Renal'1,3, 
Suprarenal, 
Phrenic, 
Hepatic. 
sometimes Middle sacral, 
Describe the portal system of veins. 
Formed by the union behind the head of the pancreas of the 
superior and inferior mesenteric, splenic, and gastric veins, collecting 
the blood from the viscera of digestion, the resulting portal vein 
divides in the transverse fissure of the liver into a branch each for 
the right and left lobe, which ramify to form a venous plexus in 
the liver tissue; the hepatic artery sends branches within the 
liver to the portal vein, and external to the organ the vein re- 
ceives the smaller gastric and the cystic vein; the portal blood 
is returned to the inferior vena cava by the hepatic veins. 
What veins return the blood from the substance of the 
heart ? 
Great cardiac vein, 
Middle cardiac vein, 
Posterior cardiac veins, 
Anterior cardiac veins, 
Right or small cardiac vein, 
Vence Thebesii. 
What is the coronary sinus ? 
A dilatation of about one inch of the great cardiac vein in pos- 
terior part of left auriculo-ventricular groove, covered by the mus- 
cular tissue of the left auricle and receiving the posterior cardiac 
veins, and an oblique vein from back of left auricle; its orifice is 
guarded by the coronary valve. 
Describe the pulmonary veins. 
Commencing in the lung capillaries they form a main vein for 
each lobule, which unite into two trunks for each lung, opening 
separately into the left auricle; at times there are three veins on 
the right side, or the two left terminate by a common opening. 184 
ESSENTIALS OF HUMAN ANATOMY. 
The Lymphatics. 
What are lymphatics ? 
Delicate vessels with transparent walls formed of same three 
coats as arteries and found in all parts of the body probably, ex- 
cept the nails, cuticle, hair, and cartilage; they have numerous 
valves producing their characteristic beaded appearance; they are 
supplied with nutrient arteries but not with nerves. 
What are the lacteals ? 
The lymphatics of the small intestine, conveying chyle during 
digestion, lymph at other times. 
Describe the lymphatic glands. 
They are small solid, round, or ovoid glandular bodies, situated 
in the course of the absorbent vessels which previous to entering 
a gland break up iuto several afferent vessels, form a plexus within, 
and emerge by several efferent vessels which soon unite to form a 
single trunk ; each gland is surrounded by a fibrous capsule which 
sends partitions inward, forming alveoli in which lies the gland- 
pulp or lymphoid tissue consisting of a rete whose meshes are filled 
with lymph-cells. The glands are chiefly found in the mesentery, 
along great vessels, in the mediastinum, axilla, neck, at front of 
elbow, groin, and popliteal space, being usually named from their 
locality, as axillary, etc. 
Describe the thoracic duct. 
This conveys the bulk of the lymph and chyle into the blood, 
being the common lymph-trunk, except for right upper extremity, 
right side of head, neck, and thorax, right lung, same side of heart, 
and convexity of liver. It commences by the triangular receptac- 
ulum chyli, on the front of body of second lumbar vertebra, enters 
the thorax by aortic opening, and opposite the upper border of 
seventh cervical vertebra it curves downward to empty at the 
junction of the left internal jugular and subclavian veins. 
Describe the right lymphatic duct. 
It is about one inch long, receiving lymph from those parts ex- 
cepted in the account of the thoracic duct, and empties at the junc- NERVOUS SYSTEM. 
185 
tion of the right internal jugular and subclavian veins; both ducts 
have double semilunar valves at their orifices, preventing regurgi- 
tation of blood. 
Nervous System 
What are the two divisions of the nervous system? 
The cerebrospinal or that presiding over animal life, and the 
sympathetic, that regulating organic life. 
Describe the structure of the nervous tissue. 
It is composed chiefly of two structures, the gray or vesicular 
originating impulses and receiving impressions; and white or 
fibrous, conducting impressions; in the sympathetic system is 
found a third structure, gelatinous nerve-tissue; seventy-five per 
cent, of nerve-tissues is composed of water, the remainder being 
albumen, phosphorized-fat, and salts. 
Describe the microscopic structure of the white nerve- 
tissue. 
It is formed of tubular fibres each consisting of a central axis- 
cylinder, surrounded by the white substance of Schwann, the whole 
enclosed by the tubular membrane ox primitive sheath. A bundle of 
these fibres invested by a fibro-areolar membrane, the perineurium 
(neurilemma), constitutes a nerve, receiving a special blood-supply 
by the vasa nervorum', the gelatinous variety consists of finely 
granular fibrillse enclosed in a sheath—by some these are not con- 
sidered to be nerves. 
Describe the gray or vesicular nerve-tissue. 
This consists of large granular cells containing nuclei and 
nucleoli, ovoid, or with one or many processes (unipolar, multipolar), 
some of which become continuous with an axis-cylinder. 
How do nerves terminate ? 
Peripherally sensory nerves end in minute plexuses, end-bulbs, 
tactile corpuscles, and Pacinian corpuscles; in the special organs 
they end in cells and in other not well ascertained ways; motor 
nerves end peripherally in plexuses or by " motorial end plates,” 
The central terminations are not well understood. 186 
ESSENTIALS OF HUMAN ANATOMY. 
What organs compose the cerebro-spinal system ? 
The brain, spinal ganglia, and the cranial and spinal nerves. 
Name the membranes of the brain. 
The dura mater, the arachnoid, and pia mater. 
Describe the cerebral dura mater with its processes. 
It is a dense fibrous membrane lining the interior of skull, con- 
stituting the internal periosteum, is continuous with that of spinal 
cord, and is prolonged to outer surface of the skull through the 
various foramina; by separation of its layers the cerebral sinuses 
are formed; its smooth under surface is covered with endothelial 
cells ; its processes are the, 
Falx cerebri, a sickle-shaped layer occupying the longitudinal 
fissure of the brain; along the upper and lower border respectively 
run the superior and inferior longitudinal sinuses. 
Tentorium cerebelli, covering the upper surface of the cerebellum; 
it supports the weight of the posterior lobes of the cerebrum ; it is 
attached to the horizontal arms of the occipital cross, enclosing the 
lateral sinuses, to the upper margin of the petrous bone, including 
the superior petrosal sinuses, whence it extends to anterior and 
posterior clinoid processes; to the mid-line, above, the falx cerebri 
is attached antero-posteriorly, and below medianly the base of the 
Falx cerebelli, a small triangular process passing between cere- 
bellar lobes behind. 
What are the Pacchionian bodies ? 
Numerous aggregations of small whitish granulations of un- 
known function formed upon outer surface of dura mater near 
superior longitudinal sinus, lying in depressions in the bone, in 
the superior longitudinal sinus, on the inner surface of the dura 
mater, and on the pia mater; unknown in infancy, rare before 
third year; they are usually found after tenth year. 
Describe the arachnoid. 
It is a delicate membrane lying between the pia mater and dura 
mater, being sepaiated from the latter by the subdural space; it 
bridges over the convolutions, forming part of subarachnoidean 
space, and at the base, by being stretched between the middle lobes, NERVOUS SYSTEM. 
187 
the anterior subarachnoidean space is left; while between the cere- 
bellar hemispheres and medulla oblongata lies the posterior sub- 
arachnoidean space, the two communicating across the crura cere- 
belli, and by an opening in its lower boundary with the fourth 
ventricle; these spaces contain the cerebro-spinal fluid, forming 
an elastic water-cushion for the encephalon: it consists of inter- 
woven bundles of fibrous and yellow elastic tissue covered with a 
layer of endothelium. 
What is the pia mater ? 
It consists of a minute plexus of bloodvessels derived from the 
internal carotid and vertebral arteries, held together by fine areolar 
tissue; it dips between the convolutions, forms the velum inter- 
positum and choroid plexuses of the fourth ventricle, and contains 
nerves and lymphatics. 
What are the divisions of the brain called? 
The cerebrum, cerebellum, pons Varolii, and medulla oblongata. 
What is the weight of the brain? 
Forty-nine and a half ounces, on the average, in males, and 
forty-four ounces in females; heaviest male brain recorded sixty- 
eight and three-eighths ounces, lightest thirty-four ounces; female 
brain, heaviest fifty-six ounces, lightest wirty-one ounces ; idiots’ 
brains seldom weigh more than twenty-three ounces. 
Name the fissures and lobes of the cerebrum. 
Each half, or hemisphere, has its external surface subdivided 
into five lobes by the 
Fissure of Sylvius, f. Sy. p., beginning at anterior perforated space, 
it passes to external surface of hemisphere and subdivides, one 
arm (precentral fissure, f. Sy. a.) ascends toward longitudinal fissure, 
one passes nearly horizontally backward. 
The fissure of Rolando,/. Bo., commences at or near middle of 
the longitudinal fissure, running downward and forward to a little 
above the horizontal branch of the Sylvian fissure. 
Parieto-occipital fissure, par. oc. f, commences about midway 
between posterior extremity of brain and fissure of Rolando, run- 
ning downward and forward for a variable distance. 188 
ESSENTIALS OF HUMAN ANATOMY 
Thq frontal lobe lies in front of the fissure of Rolando, and above 
the horizontal part of the Sylvian fissure; its under surface is 
called the orbital lobe. 
Fig. 77. 
Tcmporo- Sph.en.oi.dal. L 
Convolutions of outer surface of brain. 
The parietal lobe is bounded in front by fissure of Rolando, 
behind by parieto-occipital fissure, and below by horizontal limb 
of Sylvian fisure. 
The occipital lobe lies behind parieto-occipital fissure. 
The temporo-sphenoidal lobe occupies middle cerebral fossa of 
skull, and is limited above and in front by Sylvian fissure. 
The central lobe, or island of Reil, lies in the fissure of Sylvius 
at the base of brain. 
The inner or median surface of each hemisphere presents five 
fissures: 
The calloso-marginal fissure, c. m. f. (Fig. 78), separating the 
marginal convolution from the gyrus fornicatus, g.f. 
The parieto-occipital fissure, par. oc.f., a continuation of that of 
same name on outer surface of hemisphere. 
The calcarine fissure, calc.f., runs from back of hemisphere hori- 
zontally forward to posterior inferior extremity of gyrus fornicatus, 
g.f.; it is joined by the parieto-occipital fissure. 
The collateral fissure, coll. /., runs below and nearly parallel to 
preceding, separated by the uncinate gyrus. NERVOUS SYSTEM. 
189 
The dentate fissure, d. f., commences below posterior extremity 
of corpus callosum, running forward to end at recurved part of 
uncinate gyrus. 
The transverse fissure, between the middle lobe and crus cerebri, 
admitting pia mater into the lateral ventricles. 
Mention the principal convolutions of the brain. 
The convolutions, or gyri, are elevated ridges covered with gray 
matter, separated by deep furrows, or sutri, thus securing a great 
extent of gray matter; while not uniform in all brains, nor sym- 
metrical, certain principal convolutions are constant, such as 
The gyrus fornicatus, g./orn., that lying over corpus callosum. 
The marginal, marg. c., forming anterior superior margin of the 
great longitudinal fissure. 
The ascending frontal, asc.fr. c. (Fig. 77), forming anterior boun- 
dary of fissure of Rolando. 
Fig. 78. 
Convolutions of outer surface of brain. 
The ascending parietal, asc. par. c., the posterior boundary of 
same fissure. 
Angular gyrus, ang. c., lying between back of horizontal limb of 
Sylvian fissure, and a short fissure running upward from it. 
Other convolutions are indicated by contractions of names on 
the diagrams, so that with the preceding explanations of points of 
reference no further details are requisite. 190 
ESSENTIALS OF HUMAN ANATOMY. 
What is the quadrate lobe (Fig. 78), and what is the 
cuneus (Fig. 78)? 
The former is the marginal convolution between the calloso- 
marginal fissure in front and the parieto-Occipital behind; the 
latter lies between the parieto-occipital and calcarine fissures. 
Mention the various objects seen on the under surface of 
cerebrum, naming them from before backward. 
Longitudinal fissure4 (Fig. 79), antero-posterior, 
Fig. 79. 
Base of brain. 
Corpus callosum, the transverse commissure, connecting cerebral 
hemispheres. NERVOUS SYSTEM. 
191 
Lamina cinerea, a thin layer of gray substance, extending from 
end of corpus callosum back to tuber cinereum above optic tracts. 
Fissure of Sylvius6, separating by its horizontal limb the frontal 
and parietal lobes from temporo-sphenoidal; (o&fwomenc/afere) sep- 
arates anterior and middle lobes chiefly by the ascending or pre- 
central limb. 
Anterior perforated spaces7, between roots of olfactory nerve on 
each side for passage of vessels into corpus striatum. 
Optic commissure2\ union of optic tracts. 
Tuber cinereum, an eminence of gray matter, part of floor of third 
ventricle. 
Infundibulum?, a hollow conical process of gray matter projecting 
from middle of under surface of tuber cinereum, communicating 
with third ventricle. 
Pituitary body, a vascular, two-lobed body projecting from apex 
of infundibulum into sella turcica of sphenoid. 
Corpora albicantia9, the two small rounded, infolded terminations 
of the anterior crura of fornix. 
Posterior perforated space10, between corpora albicantia in front, 
pons Varolii behind, and cerebral crura on either side, forms part 
of floor of third ventricle, and gives passage for vessels to optic 
thalami. 
Crura cerebri11 (peduncles of cerebrum) connect the cerebrum 
with cerebellum, medulla oblongata, and spinal cord. 
Pons Varolii12 (see page 195). 
Name the five great ganglia of the brain, other than the 
gray matter of the cerebral and cerebellar hemi- 
spheres and medulla oblongata. 
Olfactory bulbs23, 
Corpora striata, 
Optic thalami, 
Tubercula quadrigernina. 
Pons Varolii12, 
Describe these ganglia. 
Olfactory bulbs23, the ganglia of the sense of smell, lie in olfac- 
tory grooves of cribriform plate of the ethmoid, and arise by two 
white roots, one crossing Sylvian fissure from a nucleus of gray 
matter in middle lobe, the other from inner back part of frontal 
{orbital) lobe, and a gray root from under surface of same lobe. 192 
ESSENTIALS OF HUMAN ANATOMY. 
Corpora striata, chief part of motor tract, lying in lateral ventri- 
cles, the intra ventricular gray portion called caudate nucleus, the 
extra-ventricular, the lenticular nucleus, the internal capsule dividing 
the two. 
Optic thalami, they are white externally, the ganglia of general 
sensation, forming the lateral boundaries of the third ventricle, 
each presenting an anterior tubercle in lateral ventricle, and pos- 
teriorly two small internal and external geniculate bodies. 
Corpora quadrigemina (optic lobes) are four rounded eminences 
situated behind third ventricle and posterior commissure; the 
anterior pair are the nates, the posterior pair the testes; they are 
the centre of vision. 
The pons Varoiii, containing much gray matter and one special 
mass called the superior olivary body, might be considered a fifth 
ganglion. 
What are the commissures ? 
Connecting bands of white or gray matter 
Enumerate them. 
Those pursuing an antero-posterior course, are 
Olfactory tracts, 
Taenia semicircular is, 
Crura cerebri, 
Peduncles of pineal gland, 
Fornix, 
Gyrus fornicatus, 
Fasciculus unciformis, 
Processus e cerebello ad testes. 
Those passing transversely, are 
Strive longitudinales. 
Anterior, 
Middle, 
Posterior, 
Corpus callosum, 
Optic chiasm, 
Pons Varoiii, 
Fornix (also a longitudinal 
commissure), 
Posterior medullary velum, 
Valve of Vieussens. 
What are the ventricles of the brain? 
Five serous cavities in the brain, four of which intercommuni- 
cate ; they are two lateral, a third, a fourth, and a fifth. 
Describe the lateral ventricles. 
The corpus callosum roofs them in ; each has an anterior cornu, 
curving outward and forward into the anterior lobe, a middle cornu NERVOUS SYSTEM. 
193 
descending into the middle lobe downward and backward, then 
turning downward and forward, containing the curved hippocampus 
major, and a posterior cornu curving downward and inward into 
the posterior lobe, containing the hippocampus minor; the floor 
from before backward is formed by the corpus striatum, tcenia serni- 
circularis, optic thalamus, choroid plexus, corpus fimbriatum, and 
fornix; the septum lueidum forms the inner wall. 
Describe the following parts : 
The corpus callosum-, it is a thick arched layer of transverse 
fibres at the bottom of the longitudinal fissure, anteriorly curving 
upon itself, giving off two peduncles to the entrance of the Sylvian 
fissure, posteriorly it becomes continuous with the fornix; a 
median linear depression on its upper surface is called the raphe, 
parallel to which on each side run two or more elevated longitu- 
dinal bands, the striae longitudinales or nerves of Lancisi. 
The tcenia semicircularis; lies in a depression between corpus 
striatum and optic thalamus and is a commissure between these 
bodies. 
Choroid plexus; the vascular margin of the velum interpositum, 
communicating with that of opposite side just behind anterior 
pillars of fornix, through the oval foramen of Monro; posteriorly, 
it descends into the middle horn, becoming there continuous with 
pia mater through transverse fissure. 
The corpus fimbriatum (tcenia hippocampi); the lateral edge of 
the posterior pillar of the fornix, forming a white band just behind 
choroid plexus. 
The fornix; continuous with corpus callosum behind, consisting 
of a triangular body with apex forward, two anterior crura, curving 
downward to base of brain, there to form the corpora albicantia 
and terminate in the optic thalami, and two posterior crura, run- 
ning down the middle cornua of the lateral ventricles, as the 
hippocampi majores; on the back under surface, between posterior 
crura, certain transverse longitudinal and oblique lines have been 
termed the lyra. 
The septum lucidum; is a vertical septum, attached above to 
under surface of corpus callosum, below to anterior part of fornix 
and prolonged portion of corpus callosum ; it is triangular in form, 194 
ESSENTIALS OF HUMAN ANATOMY. 
and consists of two lamina of white nerve matter lined internally 
with gray matter, the space between forming the fifth ventricle, not 
communicating with other ventricles. 
What is the pes hippocampi ? 
The rounded elevations of lower extremity of hippocampus 
major. 
What is the pes accessorius ? 
A white projection at the junction of the two hippocampi. 
What is the fascia dentata ? 
The gray substance of the dentate convolution, seen by raising 
the edge of corpus fimbriatum. 
What is the internal capsule ? 
A large tract of white matter belonging to pyramidal tract, con- 
sisting of two limbs, the anterior lying between anterior part of 
lenticular nucleus and caudate nucleus, the posterior between 
posterior part of lenticular nucleus and thalamus, which, by their 
junction, form a projection inward, the knee or genus. 
What is the external capsule ? 
A small tract of white matter lying between the outer part of 
the lenticular nucleus and cerebral cortex. 
Describe the third ventricle. 
Narrow and oblong, the lateral walls being the optic thalami 
and peduncles of pineal gland; above the under surface of the 
velum interpositum roofs it in, containing the choroid plexuses of 
this ventricle; the lamina cinerea, tuber cinereum, infundibulum, 
corpora albican tia, and posterior perforated space form its floor; it 
is limited in front by the anterior crura of the fornix and part of 
anterior commissure; behind, by the posterior commissure, beneath 
which opens the iter e tertio ad quartum ventrieulum; while in front 
by the foramen of Monro it communicates with the lateral ven- 
tricles ; the cavity is crossed by an anterior and posterior white 
commissure and a middle gray one. NERVOUS SYSTEM. 
195 
Describe the fourth ventricle. 
It is the space between posterior surface of the medulla oblongata 
and pons in front, and the cerebellum behind. Its roof is the valve 
of Vieussens and that portion of the cerebellum? called the nodulus, 
uvula, and amygdalae-, the lateral boundaries on each side are the 
processus e cerebello ad testes, and posterior pyramids and restiform 
bodies of the medulla oblongata; the floor consists of the posterior 
surface of the medulla oblongata and the pons, upon the former of 
which will be seen the posterior median fissure obliterated above, 
terminating below in front of calamus scriptorius at the orifice of a 
short blind canal, the remains of the foetal central canal of cord; on 
each side of median fissure are two convex longitudinal eminences, 
the fasciculi teretes; external to these, opposite crus cerebri on each 
side, is the locus cceruleus—a ganglionic mass ; a thin streak of this 
embedded gray matter continued to top of ventricle is called the 
tcenia violacece, and certain white lines, the linece transversce: this 
cavity communicates with that of the third by iter e tertio, etc., 
and with the subarachnoid space, through an opening in the pia 
mater extending between the medulla oblongata and cerebellum. 
The fifth ventricle has been described with septum lucidum, 
p. 194. 
Describe the pons Varolii. 
It is the bond of union between the different segments of the 
encephalon: bridging the medulla oblongata is a broad transverse 
band forming the middle peduncles or crura cerebelli: longitudinal 
fibres pass up from the medulla oblongata to form the two crura 
cerebri, which become connected with the corpora striata and optic 
thalami, through which they pass to reach the gray matter of the 
hemispheres forming the corona radiata: the locus niger, a mass of 
gray matter, is found in the substance of each crus; the third nerve 
emerges from inner side of each crus, the fourth nerve around the 
outer side from above, while the optic tract is adherent by its upper 
border. 
Describe the corpora quadrigemina. 
These are four rounded projections placed just behind third 
ventricle beneath posterior border of corpus callosum: they are 196 
ESSENTIALS OF HUMAN ANATOMY. 
the centre of vision. Two white bands on each side connect them 
with optic thalamus and optic tracts, those passing from the an- 
terior pair, or nates, to thalamus are the brachia anteriora, those 
running from the posterior pair, the testes, to the thalamus are the 
brachia posterior a; passing from the testes to the cerebellum on 
each side is the processus e cerebello ad testes or inferior cerebellar 
peduncle. 
What is the valve of Vieussens ? 
A thin lamina of nerve tissue, stretching from the vermiform 
process of cerebellum from one processus e cerebello ad testes to 
the other, forming the roof of the iter e tertio, etc.: a little ridge 
descending upon the upper part from the corpora quadrigemina is 
the frcenulum, and on either side are the transverse fibres connect- 
ing the fourth nerves. 
What is the pineal gland ? 
A reddish conical body lying beneath the nates, connected by 
its base by two peduncles to the anterior crura of fornix: the gland 
has a small cavity—said by some to open into that of the third 
ventricle — containing a viscid fluid and a sandy substance, the 
acervulus cerebri, composed of calcium carbonate and phosphate, 
magnesium and ammonium phosphate, with some animal matter. 
Describe the medulla oblongata. 
It is the upper enlarged part of spinal cord, extending from 
upper border of atlas to lower border of pons Varolii; its posterior 
surface forms the floor of the fourth ventricle, its anterior rests on 
the basilar groove of the occiput. It contains the vaso-motor, car- 
diac, and respiratory centres, also those of deglutition, mastication, 
etc. Divided into lateral halves by the anterior (d, Fig. 80) and, 
Posterior median fissures, it presents on each side of anterior 
fissure, 
The anterior pyramid (p, a, Fig. 80) formed by antero-lateral 
columns of the cord, these latter fibres decussating above d (crossing 
from one pyramid to that of the other) at the lower part; behind 
the pyramid is the olivary bodyo containing in its interior a capsule 
of gray matter, the corpus dentatum; behind the olivary body is, NERVOUS SYSTEM. 
197 
The lateral tract continuous with lateral tract of the cord; back 
of this is the restiforW body, continuous with posterior columns of 
cord below, above passing into corresponding hemisphere of cere- 
bellum forming ;ts inferior peduncle ; running along the posterior 
median fissure on either side are the 
Posterior pyramids continuous with posterior median columns 
of cord; diverging above, they form the lateral boundaries of the 
calamus scriptorius. 
Describe the cerebellum 
It is that portion of the encephalon contained in the inferior 
occipital fossae composed of laminae covered with gray matter; on 
the upper surface the two hemispheres are seen connected by a 
median elevated lobe, the superior vermiform process, while they are 
separated in front and behind by notches respectively called the 
incisurce cerebelli anterior and posterior; the superior vermiform pro- 
cess consists of a lobulus centralis in incisura anterior, the monti- 
culus cerebelli the central projecting portion, and the commissura 
simplex, near the incisura posterior. 
Describe the under surface of the cerebellum. 
It is divided by a central longitudinal depression, the valley, into 
two hemispheres. Projecting from the bottom of the valley is the 
inferior vermiform process, consisting of the commissura brevis in 
the posterior notch, in front of the conical pyramid, more ante- 
riorly, the uvula, lying between two rounded lobes the amygdalae or 
tonsils, and which projects into fourth ventricle, and finally in front 
of uvula the nodule; attached to each side of nodule and also to 
flocculus, is a thin white layer which together form the posterior 
medullary velum. 
Name the lobes of the cerebellum 
Below, from before backward, they are, on each side, 
The flocculus, or pneumogastric lobule, a prominent tuft below and 
behind middle peduncle. 
The amygdala, just described. 
The digastric, on outside of tonsils, partially connected with 
pyramid. 198 
ESSENTIALS OF HUMAN ANATOMY. 
The slender, behind former, connected with commissura brevis 
and back of pyramid. 
The inferior posterior, joining the commissura brevis in the 
valley. 
Only one fissure—the great horizontal—pertains to the cerebellum, 
commencing in front at pons, and passing horizontally round free 
margin of each hemisphere to median line; from this numerous 
secondary fissures proceed, marking out lobes, as two on the upper 
cerebellar surface on each side, viz., the anterior, or square globe, ex- 
tending back to posterior edge of vermiform process, and the pos- 
terior, or semilunar, passing from preceding to great horizontal fis- 
sure. 
How many peduncles has the cerebellum ? 
Three; the transverse fibres of pons Varolii, or middle peduncle; 
on each side the restiform bodies of medulla oblongata, or inferior 
peduncles; and the processus e cerebello ad testis, forming the supe- 
rior peduncles. 
Describe the arrangement of the gray matter of the cere 
bellum. 
A vertical section reveals a central stem of white matter con- 
taining a capsule of gray matter, the corpus dentatum. From the 
central white stem ten or twelve plates, or lamince, spring, giving 
origin to smaller secondary and tertiary laminae, covered externally 
by a layer of gray matter, so that the cut surface presents the foli- 
ated appearance giving origin to the name arbor vitae. 
The Spinal Cord. 
What is the spinal cord ? 
The elongated cylindrical part of the cerebro-spinal axis con- 
tained in the vertebral canal, measuring about seventeen inches in 
length, extending from upper border of atlas to lower border of 
body of first lumbar vertebra, presenting a cervical enlargement 
from third cervical to first or second dorsal vertebra, and a lumbar 
enlargement opposite last two or three dorsal vertebrae; it terminates 
by a slender filament of gray substance, the filum terminate. The THE SPINAL CORD. 
199 
white matter is disposed externally, the gray internally in the form 
of two crescents joined by a transverse commissure, the anterior 
thicker extremities, forming the anterior cornua, or horns, the pos- 
terior the posterior cornua. 
How many membranes has the cord ? 
Three; the dura mater, continuous with that of brain, but sepa- 
rated from bony walls by loose areolar tissue, containing a plexus 
of veins; the arachnoid, continuous with cerebral arachnoid, also 
having a subdural and subarachnoidean space, the latter communi- 
cating with general ventricular cavity of brain by the foramen of 
Magendie, an aperture in pia mater of fourth ventricle—this space 
contains an abundant serous secretion, the cerebrospinal fluid; and 
the pia mater, sending processes down into anterior and posterior 
median fissures, having medianly in front a fibrous band, the linea 
splendens, and on each side another, the ligamentum denticulatum, 
whose outer border presents about twenty serrations, the apices of 
each attached to inner surface of dura mater, serving to support 
the cord. 
Describe the fissures. 
They are the anterior and posterior median, dividing cord into two 
lateral halves, joined medianly by a white commissure; on each 
side of anterior fissure is a series of foramina for the exit of anterior 
roots of nerves; this line of openings is called the antero-lateral fis- 
sure; two postero-lateral fissures run parallel to posterior median fis- 
sure, giving exit to posterior roots; finally, a delicate groove on 
each side between the postero-lateral and posterior median fissures 
exists, marking off thq posterior pyramids. 
Name the columns of the cord marked off by these fissures. 
On each side the anterior, continuous with the anterior pyramid 
of medulla oblongata. 
The lateral, continuous with lateral tract of medulla oblongata. 
The posterior, continuous with restiform body of medulla oblon- 
gata* 
The posterior median, continuous with posterior pyramid of 
medulla oblongata. 200 
. ESSENTIALS OF HUMAN ANATOMY. 
What is the ventricle of the cord ? 
The fcetal central canal, usually obliterated, except for a few 
lines below floor of fourth ventricle of brain. 
The Cranial Nerves. 
How many pairs of cranial nerves are there ? 
Nine, according to most anatomists; twelve, according to others. 
Describe each of the following nerves, giving their number 
according to each classification. 
First, Olfactory1'' (Fig. 80), nerve of smell; superficial origin, by 
one root from middle lobe, two from anterior lobe (see p. 191); 
deep origin, gray nucleus in 
temporo-sphenoidal lobe, cor- 
pus striatum, and gyrus forni- 
catus; escapes, by foramina of 
cribriform plate of ethmoid; 
distribution, nasal (Schneider- 
ian) mucous membrane; may 
be regarded as lobe of cere- 
brum. 
Second, Optic11, nerve of 
sight; deep origin, from optic 
tracts117, which arise from 
optic thalami, corpora geni- 
culata, and nates of corpora 
quadrigemina; is also attached 
to crus cerebri and receives 
fibres from tuber cinereum, 
laminacinerea, and, according 
to some, the taenia semicircu- 
laris and gyrus fornicatus; in 
front of tuber cinereum lies 
the optic chiasm or commis- 
sure, formed of six sets of 
fibres, viz., a set crossing from right side of brain to left eye, a 
second pursuing the same course from the opposite side, decussating 
Fig. 80. THE CRANIAL NERVES. 
201 
fibres; a third, anterior, connecting the two retinae — inter-retinal 
fibres; a fourth and fifth, lateral,, cerebro-retinal, connecting the 
hemisphere of one side with retina of eye of same side; and a 
sixth, posterior—inter-cerebral—connecting one optic tract with the 
other; distribution, retina. 
Third111, Motor oculi; superficial origin, inner surface of crus 
cerebri; deep origin, a nucleus for each in floor of iter e tertio ad 
quartum ventriculum ; escapes, by sphenoidal fissure ; distribution, 
to all eye muscles including iris, except external rectus and 
superior oblique. 
Fourthlv (Fig. 80), Patheticus, motor, superficial origin, outer side 
crus cerebri; deep origin, floor of aqueduct of Sylvius; escapes 
through sphenoidal fissure; distribution to superior oblique of eye. 
Fig. 81. 
Fifthv (Fig. 80), Trigeminus or Trifacial, nerve of general sensa- 
tion, motion, and taste; superficial origin, by a motor and a sensory 
root froth side of pons Varolii; deep origin, sensory root from upper 
expanded posterior gray horns of medulla at junction with resti- 202 
ESSENTIALS OF HUMAN ANATOMY. 
form body—the Gasserian ganglion formed on this root lies on apex 
of petrous portion of temporal bone; the motor root arises from a 
mass of gray cells to inner side of nucleus of sensory root; escapes, 
ophthalmic3 (Fig. 81) by sphenoidal fissure, superior maxillary4 
(Fig. 81) by foramen rotundum, inferior maxillary5 (Fig. 81) by 
foramen ovale. 
Ophthalmic division3 (Fig. 81), purely sensory, supplies eyeball, 
ciliary muscle, iris, lachrymal gland, nasal and ocular mucous 
membrane, skin and muscles of eyebrow, forehead and nose, and 
ciliary ganglion; its branches are 
Frontal, Lachrymal, Nasal. 
Superior maxillary division4 (Fig. 81), sensory, is distributed to 
temple, cheek, lower eyelid, nose, upper lip, and teeth, and, by 
Meckel’s ganglion connected with this nerve, the palate and 
pharynx; its branches are 
Orbital, 
Spheno-palatine, 
Posterior dental, 
Anterior dental. 
Infra-orbital 
' Palpebral, 
[ Nasal (Fig. 81), 
Labial. 
Inferior maxillary division5 (Fig. 81), nerve of common sensa- 
tion, motion, and taste; supplies masticatory muscles, teeth, gums, 
skin of temple and of external ear, lower part of face and lower 
lip, the tongue, otic and submaxillary ganglia; its branches are 
Masseteric, 
Two deep temporal, 
Buccal, 
Pterygoid, 
Auriculo- temporal, 
Gustatory 
Mylo-hyoid, 
Incisor, 
Dental, 
Mental. 
Inferior dental 
Sixth, Abducensvi (Fig. 80), motor; superficial origin, between 
anterior pyramid and pons Varolii; deep origin, from nucleus of 
fasciculus teres on floor of fourth ventricle ; escapes, by sphenoidal 
fissure; distribution, external rectus muscle. 
Seventh, Facial™ (Fig. 80) or portio dura of the seventh nerve, 
the motor nerve of the muscles of expression, of platysma, buc- 
cinator, two muscles of external ear, posterior belly of digastric, 
stylo-hyoid, stapedius, through chorda tympani, the lingualis, 
through otic ganglion, the tensor tympani, through Vidian, the 
levator palati and azygos uvulae muscles; superficial origin, medulla THE CRANIAL NERVES. 
203 
oblongata, from groove between olivary and restiform bodies; deep 
origin, from nucleus of fasciculus teres in floor of fourth ventricle 
and nucleus of motor root of fifth nerve; escapes, by internal audi- 
tory meatus to aquseductus Fallopii, and thence by stylo-mastoid 
foramen ; distribution, to muscles already mentioned ; its branches 
are 
Tympanic, 
Chorda tympani, 
Posterior auricular, 
Temporal, 
Malar, 
Infra-orbital, 
Temporo-facial 
Buccal, 
Supra-maxillary, 
Infra-maxillary. 
Digastric, 
Stylo-hyoid, 
Cervico-facial 
The communications of the facial are 
With auditory nerve; with Meckel’s ganglion by large petrosal 
nerve; with otic ganglion by small petrosal nerve; with sympa- 
thetic on middle meningeal by external petrosal nerve ; with pneu- 
mogastrie, glosso-pharyngeal, carotid plexus, auricularis magnus, 
auriculo-temporal and with the three divisions of fifth nerve. 
Eighth, Auditoryviii b (Fig. 80), or portio mollis of the seventh 
nerve, nerve of hearing; superficial origin, from medulla oblongata 
in groove between olivary and restiform bodies at lower border of 
pons; deep origin, superior vermiform process of cerebellum, 
gray substance of posterior pyramid and restiform body; escapes, 
by internal auditory meatus; distribution, to internal ear; its 
branches are, 
Vestibular, to the vestibule, Cochlear, to the cochlea (see p. 320). 
Ninth, Glosso-pharyngeal viii a (Fig. 80) or first divsion of eighth 
nerve, nerve of general sensation and taste; superficial origin, 
medulla oblongata just behind olivary body; deep origin, gray 
nucleus at lower part of floor of fourth ventricle; escapes, at 
central part of jugular foramen, after which it presents two gan- 
gliform enlargements, the jugular and petrous ganglia-, distribu- 
tion, to muscles of pharynx, mucous membrane of pharynx, fauces, 
tonsil, and tongue, and the middle ear; its branches are 
Tympanic (Jacobson’s), 
Carotid, 
Pharyngeal, 
Muscular, 
Tonsillar, 
Lingual. 204 
ESSENTIALS OF HUMAN ANATOMY. 
Tenth, Pneumogastric* (Fig. 80) or par vagum of the eighth 
nerve\ both motor and sensory; superficial origin, from lateral 
tract of medulla oblongata behind olivary body and below the 
glosso-pharyngeal; deep origin, gray nucleus lower part of floor of 
fourth ventricle—the motor filaments probably come from spinal 
accessory ; escapes, by jugular foramen presenting agangliform en- 
largement, ganglion of the root, and lower another, ganglion of the 
trunk; distribution, to organs of voice and respiration, the pharynx, 
oesophagus, stomach, and heart; the branches are 
Auricular, 
Pharyngeal, 
Superior laryngeal, 
Recurrent laryngeal, 
Cervical cardiac, 
Thoracic cardiac, 
Anterior pulmonary, 
Posterior pulmonary, 
(Esophageal, 
Gastric, 
Hepatic (to hepatic sympathetic 
plexus). 
Eleventh, Spinal accessoryxi (Fig. 80), or third division of the 
eighth nerve, a motor nerve; superficial origin, lateral tracts of 
medulla oblongata below roots of vagus, and from same part of 
spinal cord as low as sixth cervical vertebra; deep origin, gray 
matter below nucleus of vagus and anterior horn of gray matter 
of cord; it sends filaments to ganglion of root of vagus and 
pharyngeal and superior laryngeal branches of same nerve; 
escapes, by jugular foramen, the spinal portion first entering skull 
through foramen magnus; distribution, to sterno-cleido-mastoid 
and trapezius muscles, communicating with second, third, and 
fourth cervical nerves. 
Twelfth, Hypoglossalxii (Fig. 80), or ninth nerve, motor nerve of 
tongue; superficial origin, groove between pyramidal and olivary 
bodies by numerous filaments ; deep origin, special nucleus at 
lowest point of fourth ventricle; escapes, by anterior condyloid 
foramen; distribution, to thyro-hyoid, genio-hyoid, stylo-glossus, 
hyo-glossus, genio-hyo-glossus, and by descendens noni to sterno- 
hyoid, sterno-thyroid, and omo-hyoid muscles; it communicates 
with the pneumogastric, gustatory of fifth, sympathetic, and first 
and second cervical nerves ; its branches are 
Descendens noni, Muscular, Thyro-hyoid, Meningeal. THE SPINAL NERVES. 
205 
The Spinal Nerves. 
How many pairs of spinal nerves are there ? 
Eight cervical, twelve dorsal, five lumbar, five sacral, and one 
coccygeal—thirty-one in all. 
Describe their origin. 
Each nerve arises by an anterior motor root, emerging from the 
antero-lateral fissure, and a posterior sensory, having a ganglion on 
it, springing from postero-lateral fissure; these unite to pass out 
through the intervertebral foramina—except first cervical, which 
emerges between the atlas and occiput—after which they break 
up into an anterior and posterior division, the latter, the smaller, 
supplying the spine, dorsal muscles, and integument, while the 
anterior larger divisions form plexuses whence the remainder of 
the trunk and limbs receive their nerve-supply. 
Describe the cervical plexus with its branches. 
It is formed by the anterior divisions of the four upper cervical 
nerves lying upon the levator anguli scapula? and scalenus medius 
muscles ; its branches are, 
Superficialis colli, 
Auricularis magnus, 
Occipitalis minor, 
Sternal, 
Clavicular, 
Acromial, 
Communicating, 
Muscular, 
Communicans noni, 
Phrenic. 
Describe the phrenic nerve (internal respiratory nerve of 
Bell). 
It arises from third and fourth nerves with a branch from fifth, 
runs obliquely over scalenus anticus muscle, passes across sub- 
clavian artery, enters chest across root of internal mammary 
artery, to be distributed to pericardium, pleura, and under surface 
of diaphragm and phrenic plexus; it is joined by filaments from 
sympathetic, fifth and sixth cervical, the nerve to' subclavius 
muscle, and one from union of descendens noni with the spinal 
nerves. 206 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the brachial plexus with its branches. 
The anterior divisions of the fifth and sixth, with a branch of 
the seventh cervical nerves form the outer cord, the eighth cervical 
and first dorsal form the inner cord, a branch from the latter and 
one from the united fifth and sixth join the seventh nerve to form 
the posterior cord; this is the usual, but not invariable arrangement; 
its branches are, 
Communicating, above clavicle to phrenic. 
Muscular, to longus colli, scaleni, rhomboidei, and subclavius 
muscles. 
Posterior or long thoracic (external respiratory nerve of Bell), 
from fifth, sixth, and seventh nerves, to serratus magnus muscle. 
Suprascapular, from outer cord; to supra- and infra-spinatus 
muscles and shoulder-joint. 
External anterior and internal anterior thoracic, the former from 
outer cord, the latter from inner cord ; both to pectoral muscles. 
The three scapular, the upper from communicating branch from 
outer to posterior cord, the other two from posterior cord ; to sub- 
scapular, teres major, and latissimus dorsi muscles. 
Circumflex, from posterior cord with musculo-spiral; to deltoid 
and teres minor muscles, the shoulder-joint, and skin of lower 
deltoid region. 
Musculo-cutaneous (external cutaneous), from outer cord and 
pierces the coraco-brachial muscle; to coraco-brachial, biceps, 
brachialis anticus muscles, elbow-joint, and skin of outer half of 
front of forearm. 
Internal cutaneous, from inner cord with ulnar and inner head of 
median ; to skin over biceps and that of inner half of forearm in 
front and behind. 
Lesser internal cutaneous (nerve of Wrisberg), from inner cord 
alone, or a branch from this joined with intercosto-humeral (the 
lateral cutaneous branch of second intercostal nerve, piercing ex- 
ternal intercostal muscle to supply skin of upper half of inside of 
arm), or, again, the intercosto-humeral may entirely replace it; to 
skin of inner side of arm. 
Median, from outer aild inner cords by two roots which embrace 
the axillary artery uniting in front or to its outer side, first lying 
external to brachial artery, then crossing to its inner side, passing 
between heads of pronator radii teres muscle to run between deep THE SPINAL NERVES. 
207 
and superficial flexor of fingers to within two inches of wrist, 
when it becomes superficial; its branches are, 
Muscular, to all anterior superficial forearm muscles except flexor 
carpi ulnaris. 
Anterior interosseous, to deep forearm muscles except inner half 
of flexor profundus digitorum. 
Palmar cutaneous, piercing fascia above wrist; to skin of palm 
to radial side. 
Muscular, to abductor, opponens, and outer head of flexor brevis 
pollicis. 
Five digitals, supplying both sides of thumb, index, middle, and 
radial side of ring fingers. 
Dinar, from inner cord runs behind inner condyle, thence passing 
into forearm between heads of flexor carpi ulnaris to run some dis- 
tance from ulnar artery at upper third, but close to it for rest of its 
extent; it partially supplies elbow and wrist-joints, both sides of 
little and ulnar side of ring finger and skin of forearm and hand; 
its branches are, 
Articular. 
Muscular, to flexor carpi ulnaris, inner half of flexor profundus 
digitorum, the little finger muscles, the interossei and lumbricals, 
palmaris brevis, adductor, and inner head of flexor brevis pollicis. 
Cutaneous, 
Dorsal cutaneous, 
Superficial palmar. 
Deep palmar (muscular). 
Musculo spiral, from posterior cord and branch of inner cord, 
running in same-named groove with superior profunda vessels to 
divide in front of condyle into the radial and posterior interosseus; 
its branches are, 
Radial, 
Cutaneous, 
Muscular, 
Posterior interosseous. 
Radial, to skin of ball and outer side of thumb, and that on back 
of index, middle, and part of ring fingers; 
Posterior interosseous, supplying wrist-joint and all muscles on 
back of forearm except anconeus, supinator longus, and extensor 
carpi radialis longior. 
Muscular, to triceps, anconeus, supinator longus, extensor carpi 
radialis longior, and brachialis anticus. 
Cutaneous, to skin of lower, outer, and back part of arm, forearm, 
and hand. 208 
ESSENTIALS OF HUMAN ANATOMY. 
Dorsal Nerves. 
Describe them. 
Twelve in number on each side, the first escapes between first 
and second dorsal vertebrae, the last between the last dorsal and 
first lumbar; they divide into an anterior and posterior division, the 
latter supplying spine, extensor muscles of back and dorsal integu- 
ment; the former (anterior) are, 
The intercostal nerves, each connected by one or two filaments 
with the adjacent sympathetic ganglia: the anterior division of 
the first nerve aids in the formation of the brachial plexus, its in- 
tercostal branch is small and gives off no lateral cutaneous branch: 
the lateral branch of the second nerve is the intercosto-humeral (see 
p. 206): the remaining nerves give off lateral cutaneous branches 
supplying skin of front of thorax and abdomen, while they give 
muscular branches to the intercostal and abdominal muscles. 
Describe the lumbar nerves. 
The posterior branches resemble in origin and arrangement those 
of the dorsal region, while their anterior branches form the lumbar 
and part of the sacral plexuses. 
Describe the lumbar plexus and branches. 
It is formed by loops of communication between the anterior 
divisions of the four upper lumbar nerves in the substance of the 
psoas muscle, thus, 
The first nerve gives off, 
Ilio-hypogastric, to skin of gluteal and hypogastric regions. 
Ilio-inguinal, to internal oblique muscle and skin of scrotum 
(labium in female), and upper inner part of thigh, and 
A communicating loop, to second lumbar nerve, from which arises, 
in conjunction with a branch from the third nerve, the 
External cutaneous, to skin of antero-external and posterior sur- 
faces of thigh: from the second nerve and loop from first nerve 
comes, the 
Genito-crural, to cremaster muscle and skin of front of upper part 
of thigh ; and a 
Communicating loop, to third lumbar nerve. By a branch of the 
third and fourth nerves with fibres from the second is formed the DORSAL NERVES. 
209 
Obturator, to obturator extern us and adductor muscles, hip- and 
knee-joints, also sometimes to skin of thigh and leg. 
The accessory obturator, either from obturator or formed by two 
filaments from third and fourth nerves, to pectineus muscle and 
hip-joint. 
Communicating loop, between third and fourth nerves. 
Communicating loop, between fourth and fifth nerves. 
Anterior crural, from third and fourth, with communicating 
branch from second lumbar nerve. It descends beneath Poupart’s 
ligament external to artery between the psoas and iliacus muscles 
after emerging from former, and divides into an anterior and pos- 
terior division : its branches are, within the pelvis, 
Muscular to iliacus internus, to femoral artery; external to pelvis, 
Middle cutaneous, 
Internal cutaneous, 
Long saphenous, 
Articular (hip and knee), 
Muscular. 
It supplies all the anterior thigh-muscles except tensor vaginse 
femoris, and skin of front and inner side of thigh, leg, and foot. 
Describe the sacral plexus. 
It is formed by the lumbo-sacral cord (the anterior division of 
fifth nerve with a branch of the fourth), and anterior divisions of 
three upper sacral nelves and part of that of fourth : it rests upon 
the anterior surface of the pyriformis muscle, giving oif the 
Superior gluteal, from lumbo-sacral cord passing out through great 
saero-sciatic foramen, to gluteus medius and minimus and tensor 
vaginse femoris muscles. 
Muscular branches, to pyriformis, obturator internus, gemelli, and 
quadratus femoris. 
Pudic passes out of pelvis by greater sacro-sciatic foramen to 
reenter it by lesser sacro-sciatic foramen : its branches are, 
Inferior hemorrhoidal, Perineal, Dorsal of penis. 
Muscular, to transversus peronei, accelerator urinse, erector penis 
and compressor urethrae muscles: the preceding branches supply 
analogous muscles and parts in female. 
Small sciatic, escapes by greater sacro-sciatic foramen, to skin of 
scrotum, back of leg and thigh, and gluteus maximus muscle. 
Great sciatic, is a continuation of lower part of sacral plexus, 210 
ESSENTIALS OF HUMAN ANATOMY. 
forming the largest nerve in the body. Escaping by the greater 
sacro-sciatic foramen below pyriformis muscle, it gives off these 
branches, 
Articular (to hip). 
Muscular, to biceps, semi-tendinous, semi - membranous and 
adductor magnus, and divides into the internal and external pop- 
liteal nerves. 
Give the branches of the internal popliteal nerve. 
Articular (to knee). 
Muscular to gastrocnemius, plantaris, soleus, and popliteus. 
External or short saphenous, a cutaneous branch communicating 
with external popliteal, musculo-cutaneous, and small sciatic 
nerves. 
Describe the posterior tibial nerve. 
It is a continuation of former, runs down middle of back of leg 
beneath the calf muscles to divide between the inner malleolus and 
the heel into the internal and external plantar: its branches are, 
Muscular, to tibialis posticus, flexor longus digitorum and pollicis 
muscles. 
Plantar cutaneous, to skin of heel and inner side of sole of foot. 
Internal plantar, supplying skin of sole, tarsal, and metatarsal 
articulations, the two inner lumbricals, abductor pollicis, and 
flexor brevis digitorum, with four digital branches which supply 
both sides of first, second, and third toes and inner half of fourth. 
Externalplantar, smaller than preceding, supplying flexor acces- 
sorius, abductor minimi digiti, flexor brevis minimi digiti, all the 
interossei, two outer lumbricales, adductor pollicis, transversus 
pedis muscles, and skin of little toe and adjoining side of fourth 
toe. 
Describe the external popliteal nerve. 
It descends obliquely along outer side of popliteal space close to 
tendon of biceps, giving off, 
Two articular branches to knee; cutaneous branches to skin of 
postero-external surface of leg, and a branch, the cornmunicans 
peronei, joining external saphenous nerve: it divides into the 
Anterior tibial, about one inch below head of fibula, giving rnus- THE SYMPATHETIC NERVE. 
211 
cular branches to tibialis anticus, extensor longus digitorum, pero- 
.neous tertius, extensor proprius pollicis, and extensor brevis 
digitorum, articular to tarsal and metatarsal joints, and cutaneous 
to skin of adjacent sides of great and second toes; 
Musculo-cutaneous, giving off muscular branches, to peroneus 
longus and brevis, and cutaneous, to skin of lower part of leg, and 
dorsum of foot and toes, except outer side of little and adjoining 
sides of great and second toes. 
Describe the sacral and coccygeal nerves. 
They are five in number, their long roots forming the cauda 
equina in the spinal canal; each divides into an anterior (see page 
209) and posterior division, the latter escaping by the posterior 
sacral foramina, except the fifth, which emerges between sacrum 
and coccyx, and supplies multifidus spin* muscle and skin of 
posterior gluteal region; a branch goes from third nerve to bladder; 
the two lower nerves join with coccygeal, forming loops, which 
supply skin over coccygeal region and coccygeus, levator, and 
sphincter ani muscles. 
The Sympathetic Nerve. 
What is the sympathetic nerve or system ? 
It consists of a series of ganglia with intervening commissural 
bands, forming two cords on either side of spinal column connected 
above by ganglion of Ribes on the anterior cerebral communicating 
artery, and below by ganglion impar, in front of coccyx; they also 
communicate with the spinal system of nerves. 
Locate and briefly describe the connections of the cranial 
and facial ganglia. 
Ganglion of Ribes, on anterior communicating artery, connected 
with cavernous and carotid plexuses. 
Carotid ganglion (Laumonier’s) on under surface of vessel. 
Gasserian, on fifth nerve (infra). 
Ciliary or ophthalmic, in orbit (infra). 
Sjpheno-palatine (Meckel’s), in spheno-maxillary fossa (infra). 
Otic (Arnold’s), on inner side of inferior maxillary nerve below 
foramen ovale (infra). 
Ganglia are occasionally found on middle meningeal, lingual, 212 
ESSENTIALS OF HUMAN ANATOMY. 
temporal, and pharyngeal arteries, receiving the name of their dis- 
coverer, as Bidder, Cloquet, etc. 
Ganglion of Bochdalek is situated at point of junction of one of 
the nasal branches of Meckel’s ganglion and anterior dental nerve. 
Submaxillary lies above deep portion of submaxillary gland 
(infra). 
Describe the ciliary ganglion 
Situated in the orbit between the optic nerve and external rectus 
muscle, its roots are, sensory, from nasal branch of ophthalmic (fifth 
pair); motor, third nerve; sympathetic, cavernous plexus; its 
branches are, 
Short ciliary to ciliary muscle and iris. 
Describe the spheno-palatine ganglion. 
Deeply placed in spheno-maxillary fossa, its roots are, sensory, 
from superior maxillary; motor, facial, through Vidian; sympa- 
thetic, from carotid plexus; its branches are, 
Ascending, 
Anterior palatine, 
Posterior palatine, 
Middle palatine, 
Superior nasal, 
Naso-palatine, 
Vidian, 
Pharyngeal, or 
Pterygo-palatine. 
Describe the otic ganglion. 
It lies immediately beneath foramen ovale on the inner surface 
of inferior maxillary nerve; its roots are, sensory, from auriculo- 
temporal ; motor, internal pterygoid branch of inferior maxillary, 
also facial and glosso-pharyngeal through continuation of small 
petrosal nerve; sympathetic, from middle meningeal plexus; its 
branches supply tensor tympani and tensor palati muscles. 
Describe the submaxillary ganglion. 
Situated above deep portion of submaxillary gland, its roots are, 
sensory, from gustatory branch of inferior maxillary; motor, facial, 
through chorda tympani; sympathetic, from facial plexus; its 
branches go to mucous membrane of mouth, to submaxillary gland 
and to its duct. 
Describe the petrosal nerves. 
The great petrosal (large superficial petrosal) is usually described 
as a branch of the spheno-palatine ganglion passing through the THE SYMPATHETIC NERVE. 
213 
Vidian canal, distributing twigs to mucous membrane of back part 
of nose, septum, and end of Eustachian tube, entering skull through 
foramen lacerum medium, where it divides into the large superficial 
petrosal, which enters hiatus Fallopii, receives a twig from Jacob- 
son’s nerve, and terminates in the geniculate ganglion of facial 
nerve, and the carotid (large deep petrosal) joining the carotid plexus. 
Small petrosal (small superficial petrosal) connects geniculate 
ganglion of seventh nerve with otic ganglion. 
External petrosal (external superficial petrosal) passes between 
geniculate ganglion of seventh nerve to middle meningeal plexus. 
More correctly, the-great petrosal and carotid branches may be 
said to form the Vidian nerve, which runs forward through the 
same named canal to join the spheno-palatine ganglion, supplying 
it with motor and sympathetic fibres. According to this descrip- 
tion, the twigs said to be given off by the Vidian nerve to the nasal 
mucous membrane must be considered branches of the ganglion 
running back in the same sheath. 
Describe the cervical ganglia. 
There are three on either side, viz., the 
Superior cervical ganglion. It is placed opposite second and 
third cervical vertebrae behind carotid sheath, and gives off a 
Superior branch, to internal carotid artery, forming by its division 
the cavernous plexuses and carotid plexus (with its subdivisions); 
Descending branch, connecting superior with middle ganglion; 
External branches to cranial and spinal nerves, and anterior 
branches forming plexuses on external carotid and its branches; 
Pharyngeal, forming with branches from pneumogastric, glosso- 
pharyngeal, and external laryngeal nerves, the pharyngeal plexus-, 
Laryngeal, uniting with superior laryngeal nerve and its 
branches; 
Superior cardiac, connected with other branches of sympathetic, 
and with some of pneumogastric, passes to back of aorta, the right 
joining the deep, and the left (usually) the superficial cardiac plexus. 
Middle cervical ganglion is placed opposite fifth cervical vertebra; 
by its 
Superior and inferior branches it communicates respectively with 
superior and inferior cervical ganglia; the external filaments join 214 
ESSENTIALS OF HUMAN ANATOMY. 
fifth and sixth spinal nerves, the internal are the thyroid to inferior 
thyroid artery and gland, and the middle or great cardiac nerve, 
communicating with other sympathetic branches and recurrent 
laryngeal, to terminate in the deep cardiac plexus. 
Inferior cervical ganglion is placed between base of transverse 
process of seventh cervical vertebra and neck of first rib on inner 
side of superior intercostal artery ; its superior and inferior branches 
connect it respectively with middle cervical, and first thoracic 
ganglia; the external branches join the spinal nerves, others form 
a plexus or vertebral artery; its chief branch is the 
Inferior cardiac nerve, communicating with recurrent laryngeal 
and middle cardiac nerves, terminating in the deep cardiac plexus. 
What is the carotid plexus ? 
It is a plexus situated on the outer side of the internal carotid 
artery communicating with the Gasserian and spheno-palatine 
ganglia, the sixth nerve, and tympanic branch of glosso-pharyn- 
geal; it supplies the carotid artery and dura mater 
What is the cavernous plexus ? 
It is one situated below and internal to that part of the internal 
carotid artery running alongside of the sella turcica, in the 
cavernous sinus; it communicates with third, fourth, fifth, and 
sixth nerves, and ophthalmic ganglion, and supplying carotid, it, 
with the carotid plexus, forms plexuses embracing the cerebral 
and ophthalmic arteries. 
What are the other ganglia of the sympathetic system ? 
Usually twelve thoracic, four lumbar, four or five sitfcral, one 
coccygeal (ganglion impar), and numerous ganglia connected 
with the various viscera, whence plexuses are formed named from 
their locality, or the organ. 
What are the branches of the thoracic portion ? 
Communicating, with one another and the dorsal spinous nerves, 
filaments to aorta and its divisions and to posterior pulmonary 
plexus, and 
The Great Splanchnic nerve, formed by internal branches from 
thoracic ganglia between sixth and tenth, with filaments from THE SYMPATHETIC NERVE. 
215 
upper six; it perforates crus of diaphragm to terminate in semi- 
lunar ganglion, sending branches to renal plexus and suprarenal 
capsule. 
The Lesser Splanchnic, springing from tenth and eleventh ganglia 
and cord between and communicating with great splanchnic, it 
pierces diaphragm with preceding, to join the cceliac plexus. 
Smallest, or Renal Splanchnic, arises from last ganglion, occasion- 
ally communicates with preceding, pierces diaphragm, and termi- 
nates in renal and lower part of cceliac plexus. 
Describe the solar plexus. 
It supplies all the abdominal viscera, consisting of a network of 
nerves and ganglia lying in front of the aorta and crura of dia- 
phragm, surrounding the cceliac axis and root of the superior 
mesenteric artery, extending below to the pancreas, laterally to the 
suprarenal capsules. The great and part of lesser splanchnic 
nerves of both sides and termination of the right pneumogastric 
form this plexus, in conjunction with the two semilunar ganglia, 
these latter being large, irregular gangliform masses, composed of 
smaller ganglia with interspaces between, placed by side of cceliac 
axis and superior mesenteric artery, close to suprarenal capsules, 
that on the right lying beneath the vena cava. From this are 
derived the following plexuses accompanying the same-named 
arteries to the various organs: 
Phrenic, or diaphragmatic, Suprarenal, 
Cceliac, Renal, 
Gastric, Superior mesenteric, 
Hepatic, Spermatic, 
Splenic, Aortic, Inferior mesenteric. 
Name some of the more important 
Tympanic (see p. 316). 
Great, or deep, cardiac is placed in front of bifurcation of trachea, 
and above that of pulmonary artery, behind aortic arch, and is 
formed by all sympathetic cardiac nerves (except left superior), and 
cardiac branches of recurrent laryngeal and pneumogastric (except 
left superior cardiac and left inferior cardiac of pneumogastric). 
Superficial cardiac lies beneath aortic arch in front of right pul- 216 
ESSENTIALS OF HUMAN ANATOMY 
monary artery, and is formed by left superior cardiac, left inferior 
cardiac of pneumogastric, and branches from deep cardiac plexus. 
Coronary, the posterior, chiefly from deep, the anterior from 
superficial cardiac plexus. 
Aortic, on sides and front of vessel between roots of superior 
and inferior mesenteric arteries. 
Hypogastric, lying in front of sacrum, between common iliac 
arteries, it supplies the pelvic viscera, and is formed by filaments 
from aortic plexus, and from lumbar and first two sacral ganglia, 
contains no ganglia, and divides into two lateral portions, forming 
the inferior hypogastric or pelvic plexuses. 
Inferior hypogastric plexuses. These lie upon each side of rectum 
and bladder (rectum, vagina, and bladder, in females), and each is 
formed by a continuation of the hypogastric plexus and branches 
from second, third, and fourth sacral nerves, and a few filaments 
from sacral ganglia; the branches accompany those of internal 
iliac artery, and are distributed to all the pelvic viscera; their 
branches are 
Inferior hemorrhoidal plexus. 
Vesical plexus. Vaginal plexus. 
Prostatic plexus 
Small and large 
cavernous nerves 
to penis. 
Uterine nerves. 
VISCERAL ANATOMY. 
The Digestive Organs. 
What is a viscus ? 
Any of the internal organs with their appendages, contained 
within the cranial, thoracic, or abdominal cavities. 
Of what does the digestive apparatus consist ? 
• Of the alimentary canal, a musculo-membranous tube, lined 
with mucous membrane, about thirty feet long, and extending 
from the mouth to the anus, and certain accessory organs. THE TEETH. 
217 
Name the subdivisions of the alimentary canal. 
Mouth, pharynx, oesophagus, stomach, small intestine (duode- 
num, jejunum, ilium), large intestine (caecum, colon, rectum). 
What are the accessory organs ? 
The teeth, salivary glands (parotid, submaxillary, sublingual), 
liver, pancreas, and spleen. 
The Teeth. 
What is their function ? 
To reduce the food to fragments, thus enabling the digestive 
fluids to act to best advantage. 
Into what classes are they divided ? 
Into 
Temporary, or milk teeth, ten in each jaw, viz., four incisors, two 
canines, and four molars ; 
Permanent teeth, sixteen in each jaw, viz., four incisors, two 
canines, four bicuspids or premolars, six molars. 
Of what parts does every tooth consist ? 
Of a 
Crown or body (Fig. 82), that part projecting above the gum. 
Neck, the constricted portion between crown and fang. 
*Fang, or root, that part occupying the alveolus, held there by 
the periodontium (periosteum), lining the socket; in addition, the 
teeth are steadied by the gums, composed of dense fibrous tissue 
covered with mucous membrane. 
3Pulp-cavity, an interior cavity filled with the tooth-pulp, a 
vascular connective tissue with numerous nerves, both arteries and 
nerves reaching the pulp by a canal opening at apex of fang. 
Describe the characteristics of each of the four varieties of 
teeth. 
Incisor or cutting teeth. The crown is wedge-shaped, convex in 
front, bevelled and slightly concave behind; the fang is single, 
long, conical, and transversely flattened. 218 
ESSENTIALS OF HUMAN ANATOMY. 
Canines. Crown is large, conical, convex in front, rises above 
level of other teeth; fang long, conical, compressed laterally; 
upper pair are called in common parlance “ eye-teeth,” the lower 
“ stomach-teeth.” 
Bicuspids. Crown has two projecting cusps, fang generally is 
single, laterally grooved with bifid apex; they are also called pre- 
molars. 
Molar (grinders). Crown nearly cubical, with four cusps in 
upper, and five in lower molars ; fangs, usually three for first two 
upper, and two for first two lower molars; the third molar is called 
the “ wisdom tooth ” (dens sapiential), from 
its late appearance, and usually has but one 
fang with grooves indicating a tendency to 
formation of three fangs in upper, two in 
lower jaw. 
The second temporary molar is the largest 
milk tooth, and is succeeded by the second 
permanent bicuspid. 
Describe the structure of a tooth. 
Each is formed chiefly of 
Dentine, or ivory2, composed of minute, 
wavy, branching tubes, called dental tubuli, 
embedded in a hard, homogeneous substance, 
the intertubular tissue. The tubules are 
about ¥5\jijth of an inch in diameter, divid- 
ing dichotomously, giving the wavy appear- 
ance of the cut surface, and open into the pulp cavity. Chemically 
dentine consists of twenty-eight parts of animal, and seventy-two 
of earthy matter. 
Enamel1 forms a thin crust over crown, is the densest of all 
animal tissues, containing only 3.5 per cent, of animal matter, and 
is composed of minute parallel hexagonal rods, about of an 
inch in diameter, pursuing a wavy course. 
Cement, or crustapetrosa*, is a layer of true bone commencing at 
the neck and becoming thicker toward apex of fang. 
Pulp, filling the pulp-cavity*, consisting of soft, very vascular 
connective tissue, with numerous nerves and cells, the latter being 
Fig. 82. THE TEETH. 
219 
of two kinds, columnar, called odontoblasts—arranged in a layer 
lining pulp-cavity—and fusiform cells wedged in between these 
or permeating the pulp, both having fine processes, said to be pro- 
longed into the dentinal tubules. 
Whence do the teeth obtain their blood and nerve supply? 
From the alveolar and infraorbital branches of internal maxil- 
lary, and from inferior dental artery; the nerves come from the 
anterior and posterior dental branches of the superior maxillary, 
and from the inferior maxillary division of the fifth nerve 
When do the temporary teeth appear ? 
The time is variable, but, according to the latest authority, they 
erupt as follows, expressed in months: 
Molar 
a 
o ■ 
o 
o 
o 
a 
Jh 
'o 
a 
a 
Q 
a 
3 
t—( 
O 
a 
a 
M 
a 
eS 
O 
'o 
s 
'o 
Upper. . . . 
20-30 
12-15 
18-21 
8-10 
8-10 
8-10 
8-10 
18-24 
12-15 
20-30 
Lower . . . 
20-30 
12-15 
18-24 
12-15 
4-7 
1-7 
12-15 
18-24 
12-15 
20-30 
The order of their appearance is first, lower central incisors; 
then upper central incisors, closely followed by laterals; then 
lower laterals; next upper anterior molars followed by lower; then 
upper canines followed by lower; finally, lower back molars, fol- 
lowed by upper. 
Describe the order of appearance of the permanent teeth. 
The first to appear are first molars at end of sixth year, the 
lower teeth usually preceding the upper; thus, expressed in years, 
these teeth erupt as follows: 
Upper 
Lower 
17-21 
17-21 
Wisdom. 
l l 
CO CO 
Molar. 
Molar 
o o 
Bicuspid. 
<0 CO 
Bicuspid. 
11-12 
11-12 
Caniue. 
00 QC 
Incisor. 
Incisor. 
—■I -I 
Incisor. 
00 00 
Incisor. 
11-12 
11-12 
Canine. 
CD CO 
Bicuspid 
o o 
Bicuspid. 
05 Ci 
Molar. 
l t 
CO CO 
Molar. 
T1 T1 
to to 
Wisdom 220 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the development of the teeth. 
About the seventh foetal week appears a depression in each jaw, 
the primitive dental groove, from the bottom of which is developed 
a ridge which, atrophying at intervals, leaves a row of projecting 
papillae, containing odontoblasts, which become capped with epithe- 
lial masses developed from the margins and sides of the groove, 
the enamel organ. Now the groove becomes converted into folli- 
cles, each containing a papilla, by contraction and projection of its 
margins and the ingrowth of membranous septse. 
About the thirteenth week the papillae grow rapidly, the follicles 
deepen and become closed in by the coalescence of from two to 
five small membranous outgrowths springing from their margins, 
called opercula. The lips of the dental groove advance and fuse, 
completing the saccular stage about the end of the fifteenth week. 
The more superficial portion of the groove remains open, leaving 
the secondary dental groove, in which ten lunated depressions appear 
behind each of the sacs of the milk teeth, for the ten anterior 
permanent teeth; the secondary groove closes in like the primary 
one, the follicles becoming cavities of reserve, into which papillae 
grow to be closed in as for the temporary teeth; the remaining 
teeth arise from successive expansions backward of the primitive 
dental groove. The dentine forms from without inward capped 
with enamel, and by the gradual growth of the fang the crown 
produces absorption by pressure upon the overlying bone and 
mucous membrane, when eruption occurs; the cementum is formed 
by the periodontal membrane last of all, increasing up to old age. 
The Mouth. 
What is the mouth'? 
It is an ovoid cavity in which food is masticated, bounded by 
lips in front, by cheeks and alveolar processes of both jaws with 
their contained teeth at sides, by hard and soft palate above, by 
tongue and floor of mouth below, and terminates at the anterior 
pillars of the fauces Avhere it opens into pharynx by fauces, and is 
lined by mucous membrane covered by scaly stratified epithelium 
containing numerous racemose glands, continuous with external 
skin ; it presents for examination THE MOUTH. 
221 
The hard palate, formed by palatal processes of superior maxil- 
lary and palate bones covered by the intimately adherent peri- 
osteum and mucous membrane. 
Soft palate, consisting of a fold of mucous membrane depending 
from posterior border of hard palate, enclosing muscular tissue, 
an aponeurosis, adenoid tissue, mucous glands, etc. ; the muscles 
on each side being the levator and tensor palati, palato-glossus, 
palato-pharyngeus, and azygos uvulae—the latter with fellow 
forming the median projecting conical uvula. 
Anterior and posterior pillars of the fauces, the former contain- 
ing within a fold of mucous membrane the palato-glossus muscle 
on each side, arching downward and forward from palate to base 
of tongue; the latter, the palato-pharyngei muscles, passing back- 
ward and downward to sides of pharynx. 
Isthmus faucium, bounded by pillars of fauces, base of tongue, 
and free margin of soft palate. 
Tonsils7 (Fig. 83), situated between anterior and posterior pillars 
on each side, consisting of glandular tissue containing twelve to 
fifteen openings leading into crypts lined with mucous membrane, 
external to which is a layer of closed capsules analogous to those 
of Peyer’s glands; the tonsil is only separated from the internal 
carotid artery by superior constrictor muscle. 
Openings of ducts of Stem, opposite second upper molar tooth on 
each side, delivering the secretion of parotid glands. 
Openings of ducts of Wharton, one on either side of f'nenum of 
tongue, delivering secretion of submaxillary glands. 
Openings of ducts of sublingual gland (ducts of Hivinus), from 
eight to twenty in number, they open on an elevated crest of mucous 
membrane on each side of frsenum linguae, one or more joining in 
a tube opening into Wharton’s duct called the duct of Bartholine. 
What are the salivary glands ? 
Three compound racemose glands on each side. The parotid, 
the largest, lies below and in front of ear between zygoma above, 
mastoid behind, and ramus of jaw in front—its duct is Stemon’s; 
the submaxillary lies below jaw in anterior part of submaxillary 
triangle—its duct is Wharton's; the sublingual lies beneath mucous 222 
ESSENTIALS OF HUMAN ANATOMY. 
membrane of floor of mouth against jaw, close to symphysis—its 
ducts are those of Rivinug. 
Describe the tongue. 
Its base is attached to hyoid bone by muscles, to epiglottis by 
the two lateral and one median9 glosso epiglottidean fold of 
Fig 83. 
mucous membrane, and to soft palate by anterior pillars; its tip, 
sides, dorsum, and part of under surface are free; a median raphe THE MOUTH. 
223 
and fibrous septum divide the organ into halves; its mucous mem- 
brane reflected over floor of mouth to gums forms in front an an- 
tero-posterior fold, the frcenum linguce; the tongue is formed by 
certain intrinsic muscular fibres, viz., those of lingualis, and by ex- 
trinsic muscles, the stylo-glossus, hyo-glossus, genio-hyo-glossus, 
and palato-glossus (see p. 121). The mucous membrane of tongue 
presents the 
Circumvallate papillae, numbering eight to ten, arranged on back 
part of dorsum in two lines converging behind like a letter V, 
presenting at their junction a deep mucous follicle, the foramen 
ccecuni1. 
Fungiform papilla?, scattered over dorsum, but chiefly found at 
sides and apex. 
Filiform papilla?, with secondary papillae projecting from apices, 
arranged in lines, cover the anterior two-thirds of dorsum of 
tongue. 
Racemose glands?, situated along sides beneath tip, but chiefly 
over posterior third of dorsum. 
Lymphoid tissue, collected into masses or follicles, some resem- 
bling crypts of tonsil. 
Describe the blood supply. 
This is from, 
Dorsalis linguae,, 
Sublingual, 
Ranine, 
Facial, by submental branch anas- 
tomosing with sublingual. 
Lingual 
Ascending pharyngeal. 
Describe the nerve supply. 
The gustatory branch of fifth is distributed to papillae at front 
and sides, which endows these parts with general sensibility ; and 
also by its connection with the chorda tympani becomes the nerve 
of taste. 
Lingual branch of the glossopharyngeal, supplying mucous mem- 
brane of base and sides and circumvallate papillae ; it is the nerve 
of taste for these parts. 
Hypoglossal, to muscles; the motor nerve. 
Superior laryngeal, sends a few filaments to base from its internal 
branch. 224 
ESSENTIALS OF HUMAN ANATOMY. 
What two anatomical points of surgical interest does the 
palate present in the neighborhood of the last molar 
tooth ? 
Just behind this tooth the hamular process and internal pterygoid 
plate can be felt, the point for division of tensor palati aponeurosis 
in the operation for cleft palate, and in front of this to inner side 
of last molar tooth is the posterior palatine artery as it emerges from 
the canal, sometimes requiring plugging after a cleft-palate 
operation. 
The Pharynx. 
What is the pharynx ? 
A conical musculo-membranous sac, about four and a half inches 
long, extending from under surface of base of skull to a point cor- 
responding to the cricoid cartilage in front, and the fifth cervical 
vertebra behind. It is widest opposite cornua of hyoid bone, 
narrowest below, where it terminates in the cesophagus; it is 
bounded above by basilar process of occiput, is connected posteri- 
orly with the cervical vertebrae and longus colli and recti capitis 
antici muscles; anteriorly it is incomplete, opening into the mouth, 
being attached to internal pterygoid process, pterygo-maxillary 
ligament, lower jaw, tongue, hyoid bone and larynx ; laterally, it is 
attached to styloid processes and muscles arising from them, while 
the common and internal carotid arteries, the internal jugular veins, 
and eighth, ninth, and sympathetic nerves here lie in contact 
with it. 
How many openings communicate with it ? 
Seven: the two posterior nares, two Eustachian tubes, mouth, 
larynx, and oesophagus. 
Of how many coats does it consist ? 
Three: an internal mucous, continuous with lining of mouth, etc., 
covered with ciliated epithelium down to the level of floor of 
nares, below by squamous epithelium, containing racemose glands 
most plentiful around orifices of Eustachian tubes, and much 
lymphoid tissue surrounding crypts like those of tonsil; a middle THE PHARYNX. 
225 
fibrous coat [pharyngeal aponeurosis), thick above, where the mus- 
cular fibres are wanting; and an external muscular coat composed 
of the superior, middle, and inferior constrictors, stylo-pharyngeus, 
and palato-pharyngeus muscles. 
Describe the pharyngeal muscles. 
Inferior constrictor8: origin, side of cricoid and thyroid cartilages ; 
insertion, posterior median raphe; action, constricts pharynx during 
swallowing; nerves, pharyngeal plexus, 
glosso-pharyngeal, external laryngeal, 
recurrent laryngeal. 
Middle constrictor9: origin, greater and 
lesser cornua of hyoid bone and stylo- 
hyoid ligament; insertion, posterior 
median raphe; action, same as superior 
constrictor; nerves, glosso-pharyngeal, 
pharyngeal plexus. 
Superior constrictor10: origin, lower third 
of margin of internal pterygoid plate 
and hamular process, contiguous surface 
of palate bone, reflected tendon of tensor 
palati muscle, pterygo-maxillary liga- 
ment, alveolar process above posterior 
end of mylo-hyoid ridge and side of 
tongue; insertion, posterior median raphe 
and pharyngeal spine of occipital bone; action, same as other 
constrictors; nerves, glosso-pharyngeal plexus. 
Stylo-pharyngeus6: origin, inner side of base of styloid process; 
insertion, blends with constrictor muscles, and is also inserted into 
the posterior border of thyroid cartilage; action, draws sides of 
pharynx upward and outward; nerves, glosso-pharyngeal, pharyn- 
geal plexus, the former running on outer side, and crossing muscle 
to reach tongue. 
Fig. 84. 
What is the pharyngeal tonsil ? 
A considerable mass of lymphoid tissue extending across back 
of pharynx, between the orifices of the Eustachian tubes. 226 
ESSENTIALS OF HUMAN ANATOMY. 
What arteries supply the pharynx ? 
Superior thyroid, 
Ascending pharyngeal, 
Ptery go-palatine, 
Descending palatine, to 
epiglottis, etc. 
What are its nerves ? 
Branches from pharyngeal plexus, formed by pharyngeal 
branches of glosso-pharyngeal, pneumogastric, superior laryngeal, 
and sympathetic nerves. 
The (Esophagus. 
Describe it. 
It is a muscular canal, about nine inches long, joining the 
pharynx and the stomach, commencing at lower border of cricoid 
cartilage, passing through the oesophageal opening of the dia- 
phragm, to terminate at cardiac orifice of the stomach, opposite 
the ninth dorsal vertebra ; in the neck it lies between trachea and 
spinal column and longus colli muscle, at lower part inclining to 
the left, having on either side the common carotid artery, with 
lateral lobes of thyroid gland—the recurrent laryngeal nerves 
ascend between it and tracliea; in the thorax, while a little to the 
left at first, after passing behind aortic arch, it runs to right of the 
vessel, to pass in front and to the left again before piercing the 
diaphragm. 
What coats has it ? 
It has three: an internal mucous, when empty thrown into longi- 
tudinal folds, containing numerous racemose glands, its surface is 
studded with small papillae, and it is covered by a thick layer of 
squamous epithelium; a middle cellular, loosely connecting the 
mucous and the succeeding coat; a muscular, composed of an ex- 
ternal longitudinal and internal circular layer, the fibres above con- 
sisting chiefly of the striated, but below almost entirely of the 
unstriped involuntary variety. 
Name its arteries and nerves. 
Arteries, chiefly from thoracic aorta. 
Veins, are drained by vena azygos minor. THE STOMACH. 
227 
Nerves, from oesophageal plexus, formed by pneumogastrics with 
some sympathetic filaments. 
The Stomach. 
Describe it. 
The stomach is irregularly conical, curved upon itself, present- 
ing a round base turned to left side. Moderately distended, it 
measures about twelve inches in its longest, and four inches in its 
vertical diameter. It lies in left hypochondriac, epigastric, and 
part of right hypochondriac regions, immediately behind anterior 
wall of abdomen below the liver and diaphragm, and above the 
colon; it presents for examination the 
Greater or splenic end, or fundus, situated to the left, being 
attached to the spleen by gastro-splenic omentum, and to dia- 
phragm by gastro-phrenic ligament. 
The lesser, ox pyloric end, is in contact with abdominal wall and 
under surface of liver near end of cartilage of eighth rib. 
The oesophageal, or cardiac orifice, is the highest point of the 
stomach, is funnel-shaped, and communicates with (esophagus. 
The pyloric orifice communicates with duodenum, the opening 
being guarded by a reduplication of the mucous lining containing 
numerous circular muscular fibres, forming a thick ring—this is 
called tho pyloric valve. 
The lesser curvature extends along the upper border of organ 
between the cardiac and pyloric orifices, is concave, and is con- 
nected with under surface of liver by the lesser omentum. 
The greater curvature is convex, extends along lower border be- 
tween the two orifices, and gives attachment to great omentum. 
How many coats has the stomach ? 
Four, as follows: a 
Serous, derived from peritoneum covering all parts except along 
greater and lesser curvatures, where the omenta leave a triangular 
space, along which pass the vessels and nerves; a 
Muscular, consisting of three sets of fibres: longitudinal, con- 
tinuous with the longitudinal coat of oesophagus and small intes- 
tine, more distinct along the curvatures; the circular fibres form a 
continuous layer beneath the former set, most abundant at pyloric 228 
ESSENTIALS OF HUMAN ANATOMY 
end, forming valve (supra); the oblique fibres, some passing obliquely 
from left to right, others vice versa, around the cardiac orifice, to 
which part they are chiefly limited; a 
Mucous, covered with columnar epithelium, and thrown into 
longitudinal folds or rtigce when stomach is empty, covered by 
small shallow polygonal-shaped alveoli from TJ5th to of an 
inch in diameter, into which the gastric follicles open. 
Describe the gastric glands. 
They are of three kinds, the 
Peptic follicles, lined throughout with columnar epithelium, con- 
sisting of a duct into which open several csecal tubes, in which, 
beneath the epithelium, lie large spheroidal, coarsely granular 
peptic cells; these glands are found in all parts of the stomach. 
Mucous glands, found in greatest numbers at pyloric end, and 
resemble the preceding, but are without the large peptic cells, and 
the csecal tubes are longer. 
Lenticular, or simple solitary, found especially in early life, consist- 
ing of masses of lymphoid tissue. 
Give the blood and nerve supply. 
The arteries are, gastric13, pyloric and right gastro-epiploic17 
branches of the hepatic artery1*. 
Fig. 85. 
Left gastro-epiploic21, 
Vasa brevida, 
Branches of 
Splenic artery1®. THE SMALL INTESTINE. 
229 
The veins empty into splenic and portal veins. 
The nerves are terminal branches of both pneumogastrics and 
numerous branches from sympathetic. 
The Small Intestine. 
Describe it. 
It is the narrowest part of the digestive tract, is a convoluted 
tube some twenty feet long, occupying the central and lower parts 
of the abdominal and pelvic cavi- 
ties, and is suspended from the 
spine by a fold of peritoneum 
called the mesentery, its three di- 
visions are the 
Duodenum2 (Fig. 86), as long as 
the breadth of twelve fingers, i. e., 
eight to ten inches, passing up- 
ward and backward to the right 
to under surface of liver, near 
gall-bladder—ascending portion— 
then descending in front of 
right kidney—descending portion 
— thence running transversely 
across spine to end in thejejunum 
on left side of second lumbar 
vertebra—transverse portion—the 
junction being crossed by superior 
mesenteric artery; it is only 
partially covered by peritoneum, 
has no mesentery, and surrounds 
the head of the pancreas; into 
the descending portion, to the 
inner side, pass obliquely the com- 
mon bile and pancreatic ducts. 
Jejunum3, so-called because usually empty after death, includes 
upper two-fifths of remainder of small intestine, and lies chiefly 
in the umbilical region. 
Fig. 86. 280 
ESSENTIALS OF HUMAN ANATOMY. 
Peum*, includes remainder (three-fifths) of small intestine, is 
named from its numerous coils, occupies chiefly umbilical, hypo- 
gastric, right iliac, and occasionally pelvic regions, and opens into 
the inner side of the commencement of the large intestine in the 
right iliac fossa; the orifice is guarded by a two-leaved valve (see 
page 231). 
The same as stomach. 
The mucous membrane is covered with columnar epithelium, 
arid forms transverse folds encircling the tube for one-half to two- 
thirds its circumference, forming the 
Valvulae conniventes-, they are absent in first two inches of duode- 
num and almost disappear in lower part of ileum; villi cover the 
surface, formed of a central lacteal vessel accompanied by un- 
striped muscular tissue, an encircling plexus of capillaries, lym- 
phoid tissue and granular corpuscles, all enclosed by a basement 
membrane supporting columnar epithelium : their number is esti- 
mated at four million; the 
Cellular coat connects mucous with muscular coat, and contains 
the intestinal vessels; the 
Muscular coat, externally is composed of longitudinal and in- 
ternally of circular fibres, these not forming complete rings. 
What coats has the small intestine ? 
Describe the glands of the small intestine, 
They are, 
Brunner's (/lands, resembling pancreas in structure, and are 
limited to duodenum and commencement of jejunum. 
Simple follicles or glands of Lieberkuhn, are minute tubular de- 
pressions lined with columnar epithelium. 
Solitary glands, most numerous in lower part of ileum, but 
found in all parts, and consist of masses of lymphoid tissue about 
half a line to a line in diameter. 
Beyer s glands or patches are twenty to thirty ovoidal patches 
composed of numerous solitary glands (hence named agminated 
glands), situated opposite to mesenteric attachment, their long 
axis lengthwise, and are largest and most numerous in ileum, 
although occasionally seen in duodenum ; the valvulae conniventes 
cease at their margins. THE LARGE INTESTINE. 
231 
Name bloodvessels and nerves. 
The arteries are from gastro-duodenal of hepatic and superior 
mesenteric arteries; the veins chiefly empty into portal vein; nerves 
are, from superior mesenteric plexus of sympathetic. 
The Large Intestine. 
Describe it5,7,8/. 
It extends from ileum to anus, is about five feet long, is large 
and sacculated, has the same coats as small intestine, the mucus 
destitute of villi, but thrown into crescentic folds by the longi- 
tudinal muscular fibres which are disposed in three bands, shorter 
than the other coats, so forming them into pouches. 
Describe the subdivisions of the colon. 
They are, 
The caecum* or caput coli, the dilated commencement of the large 
bowel situated in the right iliac fossa, and usually wholly covered 
by peritoneum. 
The appendix vermi/ormis6, a narrow, blind-ended, worm-like 
tube, from three to six inches long, springing from lower back 
part of caecum, held, coiled upon itself, by a peritoneal fold. 
The ileo-coecal valve (or Bauhin’s) is formed by two horizontal 
semilunar folds of mucous membrane at the termination of ileum in 
caecum, opening toward large intestine and guarding against re- 
flux from large into small bowel; the mucous folds are reinforced 
by circular muscular fibres, and the surfaces toward the ileum are 
covered with villi, while these are absent on the caecal side. 
The ascending colon’’ extends up from caecum in front of right 
kidney, to under surface of liver to right of gall-bladder, where 
abruptly bending to the left, it forms the hepatic flexure; it is 
almost—sometimes entirely—enveloped in peritoneum, in which 
latter event it has an ascending meso-colon. 
The transverse colon8 traverses the abdomen from right to left, 
just below liver, stomach, and spleen, to left hypochondriac region, 
where it curves downward beneath lower end of spleen, forming 
th e splenic flexureit has a wide transverse meso-colon, attaching 
it to the spine. 232 
ESSENTIALS OF HUMAN ANATOMY 
The descending colon9 passes down in front of left kidney to left 
iliac fossa and is only partially covered with peritoneum, its pos- 
terior surface usually being free. 
The sigmoid flexure10, the narrowest part, lies in left iliac fossa 
extending from descending colon at crest of ilium to left sacro- 
iliac symphysis; it is curved like an S, and is held in place by a 
loose peritoneal fold, the sigmoid meso-colon. 
The rectum11 extends from left sacro-iliac symphysis to anus, is 
from six to eight inches long, curves slightly to right and then 
adapts itself to sacral curve, and near top of coccyx inclines back- 
ward to anus; it is non sacculated, but ju3t above anus presents a 
considerable dilatation; it is only covered with peritoneum at its 
anterior portion—except above—while its lower inch and a half is 
destitute of any such covering; the longitudinal muscular fibres 
form a continuous layer around the rectum. 
What are the appendices epiploic* ? 
They are little peritoneal pouches filled with fat placed along 
colon and upper part of rectum. 
What guards the anal orifice ? 
The sphincter ani and internal sphincter; a third has been 
described as some three inches up the bowel (see page 331 
What are the folds of Houston ? 
Three semilunar folds of mucous membrane, one at upper right 
side of rectum, one at left middle portion, and one projecting from 
front of rectum opposite bladder. 
Name the glands of the large intestine. 
Follicles of Lieberkiihn and solitary glands. 
Give the blood- and nerve-snpply of the large intestine 
and rectum. 
The arteries are branches of the superior and inferior mesenteric, 
the middle hemorrhoidal from the internal iliac, and the inferior 
hemorrhoidal from internal pudic. 
The nerves come from sympathetic plexuses around mesenteric 
arteries, and, in case of rectum, the fourth anterior sacral nerve 
supplies the sphincter muscle. THE LIVER. 
233 
Describe it. 
The Liver. 
It occupies the right hypochondriac region extending across the 
epigastrium into the left hypochondriac. It is the largest gland in 
the body, weighing from three to four pounds, its transverse diam- 
eter is from ten to twelve inches, its antero-posterior six to seven, 
its thickest part behind three inches. Covered by peritoneum, 
except at attachments of ligaments and bottom of fissures, it 
possesses a fibrous coat, covering the whole organ continuous with 
the capsule of Glisson at transverse fissure; there are five fissures, 
five lobes, five ligaments, and five sets of vessels; the 
TJpper surface is convex, smooth, lying in contact with dia- 
phragm above, and below with a small portion of abdominal 
wall; it is divided into two unequal lobes by a peritoneal fold, the 
suspensory ligament ; the 
Under surface is concave, is in relation with stomach, duodenum, 
Fig. 87. 
hepatic flexure of colon, right kidney, and suprarenal capsule, 
and is divided by a longitudinal fissure 8,9, into a right and left 
lobe; the 
Anterior border4 is thin, sharp, and deeply notched at site of 234 
ESSENTIALS OF HUMAN ANATOMY. 
round ligament; it corresponds usually with margins of ribs in 
males, projecting a little lower in women and children ; the 
Posterior border3 is rounded and grooved, or even perforated, by 
inferior vena cava. 
Describe the ligaments. 
They are five in number, four being composed of folds of peri- 
toneum, the fifth is the obliterated umbilical vein ; the 
Suspensory or broad ligament18 (falciform) is a falciform antero- 
posterior peritoneal fold, with apex backward, attached to liver 
from notch on anterior border to posterior border,—its anterior 
free edge enveloping the round ligament—and to diaphragm and 
sheath of right rectus muscle as low as umbilicus ; the 
Coronary ligaments consist of two layers reflected from diaphragm 
on upper and lower margins of posterior border of organ, between 
which firm areolar tissue binds the liver to diaphragm ; the 
Lateral ligaments, right and left, triangular, are formed of two 
layers of peritoneum extending from sides of diaphragm to ad- 
jacent margins of posterior border of liver; the 
Round ligament11, a fibrous cord, ascends from umbilicus in an- 
terior free margin of broad ligament to longitudinal fissure, trace- 
able back to vena cava, the back portion, the remains of ductus 
venosus, the anterior of umbilical vein. 
Describe the fissures. 
They are five in number, dividing the under surface of the 
organ into five lobes; the 
Longitudinal fissure??, extends from notch on anterior border to 
posterior border, separating right and left lobes, and is joined by the 
transverse fissure10 at posterior third ; the anterior two-thirds of the 
longitudinal fissure is called the umbilical fissure from lodging foetal 
umbilical vein, the posterior third the fissure of the ductus venosus 
lodging the obliterated foetal vessel; the anterior part of the former 
is often partially bridged over by the pons hepaticus ; the 
Transverse fissure10 is about two inches long, passing transversely 
across under surface of right lobe from junction of posterior and 
middle thirds of longitudinal fissure; here enter the portal vein, 
hepatic artery, and nerves, and the bile ducts and lymphatics 
emerge; the THE LIVER. 
235 
Fissure of the gall-bladder14 lies parallel and to right of longi- 
tudinal fissure reaching back nearly to transverse fissure; the 
Fissure for vena cava is short and deep, sometimes converted 
into a canal, extending obliquely upward from a little behind 
right extremity of transverse fissure to posterior border of liver, 
there joining the fissure of ductus venosus ; the hepatic veins here 
empty into vena cava. 
Describe the lobes of the liver 
They are five in number; the 
Right lobe1, the largest, of a quadrilateral form, its under surface 
marked by three fissures : viz., transverse, for gall-bladder, and 
for inferior cava, and by an anterior depression for colon, a pos- 
terior one for right kidney; the longitudinal fissure forms the 
division between this and the 
Left lobe2, smaller and flattened, resting by its anterior concave 
surface on stomach; the 
Lobus quadratus’ is marked off from under surface of right 
lobe by transverse fissure behind, by that for the gall-bladder on 
the right, and anterior part of longitudinal fissure on left; the 
Lobus Spigelii6 projects from back under surface of right lobe, 
bounded in front by transverse fissure, on right by that for cava, 
and on left by posterior third of longitudinal fissure; the 
Lobus caudatus1 is a small elevation running obliquely outward 
from base of lobus Spigelii to under surface of right lobe; it inter- 
venes between right end of transverse fissure and commencement 
of that for vena cava. 
Describe the vessels of the liver. 
They number five, viz., hepatic artery, portal vein, hepatic vein, 
hepatic duct, and the lymphatics; the first three are enveloped in 
loose areolar tissue called capsule of Olisson, which accompanies 
the vessels through the portal canals in the interior of the organ; 
the 
Portal vein”, about four inches long, is formed by the junction of 
superior mesenteric and splenic veins, the latter receiving the 
blood returned by inferior mesenteric vein, while the gastric veins 
empty into the portal vein itself. Entering the transverse fissure it 
divides into branches for right and left lobe, which receive the 236 
ESSENTIALS OF HUMAN ANATOMY. 
vaginal and capsular veins, and subdividing form interlobular veinsb 
(Fig. 88), which send branches to interior of each lobule forming 
a plexus converging to empty into the central intra-lobular veina 
running at right angles to other vessels; the intra-lobular vein 
empties into a sufylobular vein, a radicle of hepatic vein ; the 
Hepatic veins16 (Fig. 87) commence in sublobular veins as just 
described, which unite to form three large and several smaller 
branches terminating in inferior in fissure for that 
vessel; the 
Fig. 88. 
Hepatic artery12 springs from coeliac axis, enters transverse 
fissure, and divides into branches which ramify in the capsule of THE LIVER. 
Glisson—vaginal, supplying nutriment to vessels, ducts, etc., cap- 
sular to terminate in external fibrous coat—and ends in a plexus 
on outer surface of each lobule formed by ultimate branches of 
portal vein, the interlobular plexus above described ; the 
Hepatic rf/<dabove13 is formed by the union of two trunks of 
nearly equal size which emerge from the transverse fissure, one 
from the right and other from left lobe; it passes downward to the 
right for one inch and a half to be joined by the cystic duct from 
the gall-bladder, to form the ductus communis choledochus (see 
p. 238); the 
Lymphatics accompany bloodvessels, and consist of a deep and 
superficial set. 
Whence do the nerves of the liver come ? 
From the hepatic plexus of the sympathetic, from the pneumo- 
gastric nerves, especially the left, and right phrenic. 
Describe the liver structure. 
It is composed of numerous lobules from one-twentieth to one- 
tenth of an inch in diameter, of irregular form in human liver, 
polygonal in pigs, their bases clustered round the sublobular vein, 
to which each is connected by its intralobular vein ; the lobules 
are bound together by loose areolar tissue; each lobule is formed 
of hepatic cells, spheroidal or many-sided nucleolo-nucleated cells, 
measuring from one-one thousandth to one-two thousandths of an 
inch, containing granular yellow coloring matter and globules, 
which cells lie in the meshes of the dense capillary network 
occupying its interior, spaces between the cells forming inter- 
cellular biliary passages?, the radicles of the bile ducts. 
What is the capsule of Glisson? 
The areolar tissue entering the transverse fissure, surrounding 
the hepatic vessels to their ultimate ramifications, and continuous 
with fibrous coat of organ. 
How may the portal be distinguished from the hepatic 
veins in a liver section ? 
The portal veins are collapsed, being surrounded by the capsule 
of Glisson, while the hepatic are patulous, being closely connected 
with liver substance. 238 
ESSENTIALS OF HUMAN ANATOMY 
Describe the gall-bladder14. 
It is a pear-shaped, fibro-muscular receptacle for the bile; its 
fundus and under surface of body and neck covered by peritoneum, 
while its interior is lined with a cylindrical-celled, epithelial- 
coated mucous membrane, presenting a honeycombed appearance 
from the confluence of numerous minute rugae; its length is from 
three to four inches, its capacity from eight to twelve fluidrachms, 
and it lies in a fissure on the under surface of liver, its fundus— 
most dilated portion—projecting slightly beyond the anterior border, 
touching abdominal wall just below ninth costal cartilage; the 
narrow neck curves upon itself like an italic /, to terminate in the 
cystic duct, which is about one inch long, and is lined by mucous 
membrane so disposed in a series of crescentic folds as to present 
the appearance of a spiral valve; it joins the hepatic duct to form 
the common bile-duct. 
Describe the ductus communis choledochus13 (Fig. 87), 
It is about three inches long, three-sixteenths of an inch in 
diameter, and is formed by the junction of the hepatic and cystic 
ducts; it opens usually by a common orifice with the pancreatic 
duct, a little below the middle of inner side of descending portion 
of duodenum; its walls are composed of fibrous with a little mus- 
cular tissue, its mucous membrane is covered with columnar epithe- 
lium, and it runs between the layers of gastro-hepatic process of 
the peritoneum. 
The Pancreas. 
Describe the pancreas9 (Fig. 85). 
It is a compound racemose gland, from six to eight inches long, 
by one and one-half inches at its widest part, lying behind the 
stomach and in front of the first lumbar vertebra. It is composed 
of lobules connected by areolar tissue, each lobule consisting of 
an ultimate branch of the duct lined with columnar epithelium, 
terminating in csecal pouches or acini, also lined with cylindrical 
epithelium, outside of which is a fine capillary network. The 
Pancreatic duct {canal of Wirsung) extends the whole length of THE SPLEEN. 
239 
gland and opens into middle of descending part of duodenum, to 
the inner side, with common bile-duct; its 
Head or right extremity is embraced by the concavity of the 
duodenum, the common bile-duct lying behind, the pancreatico- 
duodenal artery in front; the 
Tail or left extremity reaches spleen above left kidney and supra- 
renal body; the 
Body is covered by the ascending layer of transverse meso-colon 
and posterior surface of stomach ; posteriorly, the superior mesen- 
teric artery and vein, the portal vein, the vena cava, and the aorta 
separate it from the first lumbar vertebra. 
The arteries18 (Fig. 85) are derived from the splenic, pan- 
creatico-duodenal branch of hepatic and superior mesenteric 
arteries. 
The veins empty into splenic and superior mesenteric veins. 
The nerves come from the splenic plexus of the sympathetic. 
What is the lesser pancreas ? 
A lobular fold, passing transversely to the left behind the supe- 
rior mesenteric vessels, which is sometimes detached from the 
gland when it may open into duodenum by a separate duct an 
inch or more above the pancreatic duct. 
The Ductless Glands. 
What are the ductless glands ? 
The spleen, suprarenal capsules, thyroid and thymus glands, 
bodies whose functions are uncertain and which have no ducts. 
The spleen and suprarenal capsules lie in the abdominal cavity, 
but the others will be for convenience described after them. 
Describe it. 
The Spleen10 (Fig. 85). 
It is a soft, brittle, very vascular, oblong, flattened organ em- 
bracing the cardiac end of the stomach, to which it is attached by 
the gastro-splenic fold of peritoneum, which latter membrane 
completely invests the spleen, except where the gastro-splenic 240 
ESSENTIALS OF HUMAN ANATOMY. 
omentum and suspensory ligament are attached; the organ lies 
deeply in the left hypochondriac region; the 
Older surface is convex, smooth, lying in contact with diaphragm, 
which separates it from the ninth, tenth, and eleventh ribs; the 
Inner surface is concave, lies in contact with stomach, and 
presents the 
Hilum, a vertical fissure pierced at various points by bloodvessels, 
lymphatics, and nerves ; the 
Anterior border is often notched, and the 
Posterior border is rounded and in relation with left kidney ; the 
Suspensory ligament, a peritoneal fold, connects it with the under 
surface of diaphragm ; the 
Fibro-elastic coat, beneath the serous (see above) which inti- 
mately adheres to it, forms the framework of the spleen, passing 
inward at the hilum with the vessels as sheaths, from which, and 
the inner surface of capsule, numerous bands or trabeculae pass, 
uniting to form numerous small spaces or areolae filled with the 
splenic pulp. 
Describe the spleen-pulp. 
It is of a dark reddish-brown color, and under the microscope is 
seen to consist of a network of branched connective-tissue cells, 
containing pigment granules (broken-down blood corpuscles), 
granular matter, nucleated cells, free nuclei, and red blood-cells 
in all stages of disintegration ; the 
Splenic artery20 (Fig. 85) is large, tortuous, and divides at 
hilum into five or six branches which do not anastomose to any 
extent, each branch breaking up again and again into smaller 
ones, until they terminate in bundles of straight vessels which 
open into the interstices of the reticulum formed by the branched 
connective-tissue cells. 
What are the Malpighian bodies ? 
Small, rounded, expanded masses of the lymphoid tissue of the 
external coat of the small splenic arteries, from one-one hundredth 
to one twenty-fifth of an inch in diameter, usually surrounding 
the vessel, but sometimes projecting from one side ; they are com- 
posed of a delicate reticulum packed with lymph corpuscles and 
pervaded by capillaries; the THE THYROID GLAND 
241 
Splenic vein arises from the lacunar spaces in the pulp, and 
empties into the portal vein ; the 
Nerves are derived from the right pneumogastric nerve and the 
right and left semilunar ganglia. 
The Thyroid Gland. 
Describe it. 
It consists of two lateral lobes situated at the sides of the upper 
portion of the trachea, connected about their lower thirds by n 
narrow transverse portion, the isthmus, which is occasionally 
absent. A third lobe, the pyramid, sometimes springs from the 
left upper side of isthmus, or the left lobe, and extends to hyoid 
bone; it is at times detached; occasionally a slender muscular 
band—the levator glandulce thyroidece—extends from hyoid bone to 
isthmus or the pyramid. Structurally, the gland consists of a 
connective-tissue capsule, sending in septa subdividing the organ 
into lobes, each of which is formed of numerous closed vesicles 
filled with a viscid yellowish fluid embedded in connective tissue 
containing a dense vascular plexus surrounding the vesicles. 
What arteries supply this gland ? 
The superior and inferior thyroid branches respectively of ex- 
ternal carotid and thyroid axis, and at times the middle thyroid, or 
thyroidece imn, springing either from the innominate artery or 
aortic arch, itself to pass up on the front of the trachea. These 
vessels are remarkable for their size and frequent anastomoses. 
(For description of those vessels, see pages 159 and 161.) 
Describe the veins of the thyroid gland 
They form a plexus on the surface of the gland, whence arise the 
Superior thyroid vein, 
Middle thyroid vein, 
Emptying into internal jugular vein. 
Inferior thyroid vein opening into innominate vein. 
Name the nerves. 
Branches of the pneumogastric nerves and of middle and inferior 
cervical ganglia. 242 
ESSENTIALS OF HUMAN ANATOMY. 
Describe it. 
The Thymus Gland. 
This is a temporary organ of unknown function, reaching its 
full development at the end of the second.. year, after which it 
gradually atrophies, having nearly disappeared at puberty. When 
fully developed it extends from fourth costal cartilage to lower 
border of thyroid gland, consisting of two lateral lobes in close 
contact along the middle line, while sometimes an intermediate lobe 
exists; the sternum and origins of the sterno hyoid and sterno- 
thyroid muscles cover it, as it lies in the neck behind these muscles 
upon front and sides of trachea; it rests, in the mediastinum, upon 
the pericardium, the thoracic fascia separating it from the aortic 
arch and great vessels. Its dimensions are: length, two inches, 
breadth, one and a half inches, thickness, three to four lines ; at 
birth it weighs about half an ounce. 
Describe its structure. 
It is formed of numerous lobules bound together by delicate 
areolar tissue, all being inclosed by a fibrous capsule; the lobules 
are composed of a cortical lymphoid tissue, and a medullary portion 
containing a few lymphoid cells, but toward the centre granular 
cells and concentric corpuscles exist. Each follicle is surrounded 
with a capillary plexus. 
Describe the arterial and nerve supply. 
The arteries are derived from internal mammary, and superior 
and inferior thyroid. 
The veins empty into thyroid and left innominate veins. 
The lymphatics arise in the substance of the gland, and are said 
to empty into internal jugular vein. 
The nerves are very minute, coming from pneumogastric and 
sympathetic. 
The Suprarenal Capsules. 
What are they ? 
Two triangular or semilunar flattened bodies, situated behind 
peritoneum, immediately in front of upper part of each kidney. THE ABDOMINAL CAVITY. 
243 
They consist of a thin, closely adherent fibrous capsule, which sends 
numerous communicating partitions inward, a cortical and medul- 
lary portion, the former containing groups of finely granular poly- 
hedral cells, with a channel between them and the fibrous portions, 
believed to be a lymph sinus; the medullary portion is formed of 
stout connective-tissue bundles, between which lie coarsely granu- 
lar columnar and branched cells, which have been thought to com- 
municate with the nerve fibres of the very fine plexus found in the 
medulla. 
What parts do these organs lie in contact with ? 
The lower concave border rests upon upper end of kidney ; their 
anterior surfaces touch respectively the under surface of liver, 
pancreas, and spleen; their posterior surfaces lie upon crura of 
diaphragm, opposite tenth dorsal vertebra, and their inner margin 
is related to the great splanchnic nerves and semilunar ganglia, on 
the right side touching vena cava, on left aorta. 
Name its vessels and nerves. 
The arteries are the suprarenal and branches of inferior phrenic 
and renal arteries forming a dense capillary network in its inte- 
rior; the 
Veins return blood from the medullary venous plexus by supra- 
renal veins into inferior vena cava on right side, and on left into 
renal vein; the 
Nerves are very numerous, chiefly distributed to medulla, and are 
derived from solar and renal plexuses and phrenic and pneumo- 
gastric nerves, having developed upon them numerous small 
ganglia, whence the opinion held by some that these bodies belong 
to the sympathetic nervous system. 
The Abdominal Cavity. 
What is the abdomen ? 
An ovoidal cavity, limited above by the thorax, below by the 
brim of pelvis; in front and at sides, by lower ribs, abdominal 
muscles, and venter ilii; behind, by spine, psoas, and quadratus 
lumborum muscles; it is lined with peritoneum—a serous mem- 244 
ESSENTIALS OF HUMAN ANAlOMY. 
brane—which is reflected to form partial or complete investments 
for the contained organs or viscera. 
Name the abdominal viscera. 
Stomach, 
Liver, 
Spleen, 
Kidneys, 
Bladder (when full), 
Uterus (during pregnancy), 
Receptaculum chyli, 
Intestines, 
Gall-bladder, 
Pancreas, 
Suprarenal capsules, 
Abdominal aorta, 
Inferior vena cava, 
Thoracic duct. 
Describe the openings in its walls. 
They are the 
Umbilical, for foetal umbilical vessels, obliterated after birth, 
leaving a depression, the umbilicus. 
Opening for inferior vena cava, in diaphragm. 
Aortic opening, behind diaphragm between crura, for aorta, vena 
azygos major, thoracic duct, and sometimes left sympathetic nerve. 
Qdsophageal opening, in diaphragm for oesophagus and pneumo- 
gastric nerves. 
Internal abdominal ring, on each side, for spermatic cord in male, 
round ligament in female. 
Femoral, or crural ring, on each side, below Poupart’s ligament, 
for femoral vessels. 
Into what regions is the abdomen artificially divided ? 
Into nine, by two imaginary parallel lines encircling the body 
on a level with ninth costal cartilages and summits of iliac crests, 
and two other parallel lines drawn from the cartilage of the eighth 
rib on each side to the centre of Poupart’s ligament. 
What are these regions named, and what does each con- 
tain? 
The right lateral are, from above downward (see cut), the 
Right hypochondriac, which contains right lobe of liver, gall- 
bladder, hepatic flexure of colon, upper part of right kidney, and 
part of right suprarenal capsule. THE ABDOMINAL CAVITY 
245 
Right lumbar, contains ascending colon, lower part of right 
kidney, and some coils of small intestine. 
Fig. 89. 
Right inguinal {iliac), contains caecum and appendix vermiformis, 
ureter, spermatic vessels. 
The median regions are, from above downward (see cut); the 
Epigastric, contains middle and pyloric end of stomach, left lobe 
of liver, lobulus Spigelii, pancreas, duodenum, parts of kidneys 
and suprarenal capsules, aorta and branches, vena cava, semilunar 
ganglia, thoracic duct. 
Umbilical, contains transverse colon, part of great omentum and 
mesentery, transverse portion of duodenum, and some coils of 
jejunum and ileum, part of both kidneys, and the receptaculum 
chyli. 246 
ESSENTIALS OF HUMAN ANATOMY. 
Hypogastric, contains coils of small intestine, the bladder in 
children, or when distended in ddults, and the uterus during 
latter six months of pregnancy, often caecum, appendix vermi- 
formis, and sigmoid flexure of colon. 
Left lateral regions from above downward (see cut) are, 
Left hypochondriac, contains splenic end of stomach, spleen, and 
tail of pancreas, splenic flexure of colon, upper half of left kidney, 
and part of left suprarenal capsule. 
Left lumbar, contains descending colon, part of omentum, lower 
part of left kidney, and some coils of small intestine. 
Left inguinal (iliac), contains sigmoid flexure of colon, ureter, 
spermatic vessels. 
The Peritoneum. 
Describe it. 
A serous membrane forming a closed sac (in male), the layer 
covering the walls being called the parietal, that reflected over 
the viscera, the visceral layer; it is coated with a layer of flattened 
endothelium, its attached surface being connected with subjacent 
parts by the subperitoneal areolar tissue or fascia. 
Does the peritoneum always form a closed sac ? 
No; in the female the Fallopian tubes open into its cavity. 
How is the peritoneum divided for convenience of descrip- 
tion? 
Into the greater sac15, or that covering upper anterior portion of 
liver5, the stomach8 behind and above, descending to ileum forming 
the anterior layer of great omentum15, the under surface of meso- 
colon20, the mesentery21, and reflections23 upon and between the 
rectum11, uterus in female22, and bladder13, then lining the antero- 
lateral abdominal walls to reach, from the under surface of dia- 
phragm17, the upper surface of liver, the starting-point of this 
description (see Fig. 90). 
The lesser sac, or cavity of the great omentum16, starting from 
diaphragm behind, this layer passes over back of liver18, then THE PERITONEUM. 
247 
covers back and under side of stomach6, forms the inner layer of 
great omentum16, passes over colon7 completing meso-colon20, and 
thence passes over duodenum9 and pancreas10 to line the posterior 
abdominal wall, reaching the point 
started from; the two cavities com- 
municate through the foramen of 
Winslow. 
Describe the foramen of Wins- 
low18 (Fig. 90). 
It is an opening at the con- 
stricted portion of peritoneum 
where it curves around the hepatic 
vessels. 
Does this foramen transmit 
anything ? 
No; it is merely the orifice of 
communication between the two 
sacs. 
What are the omenta ? 
Three folds of peritoneum, viz., 
the 
Gastro-hepatic, or lesser omentumi18, extending between the trans- 
verse fissure of liver and lesser curvature of stomach, consisting of 
two layers, the anterior pertaining to the greater, the posterior to 
the lesser sac, which enfold at the right free border the hepatic 
artery, common bile-duct, portal vein, lymphatics, and hepatic nerve 
plexus. 
The great, or gastro-colic omentum}*, is formed of four layers, two 
descending, one from the anterior, the other from posterior wall of 
stomach, and uniting below to pass as low as pelvis, when they 
ascend to transverse colon, separate and embrace this part of 
the bowel; the 
Gastro-splenic omentum is the fold connecting spleen with 
stomach, contains the splenic vessels and vasa brevia, and is con- 
tinuous below with the great omentum. 
Fig. 90. 248 
ESSENTIALS OF HUMAN ANATOMY 
What are the mesenteries ? 
Double layers of peritoneum embracing various portions of in- 
testinal tube (except duodenum), which they suspend from poste- 
rior abdominal walls; between the folds run the vessels of the 
part suspended. They are called, the 
Mesentery21, meso-ccecum, meso-colon20, mesa-rectum. 
What other name is given to suspensory folds of perito- 
neum ? 
Ligaments, such as, 
The gastro-phrenic, slinging stomach from diaphragm. 
The longitudinal, two lateralu, and coronary ligaments of liver. 
The vesical, five so-called false ligaments. 
Two vesico-uterine2S, two recto-uterinen, two broad ligaments of 
uterus. 
Suspensory ligament of spleen connecting this organ with dia- 
phragm. 
Mention the viscera and partially(2) covered with 
peritoneum and those totally deficient(3) in such 
investment. 
(1) The spleen, small intestine?, caecum, transverse colon1, sigmoid 
flexure, ovaries, uterus, stomach9 and liveA practically, duodenum (first 
part), rectum11 (upper third). 
(2) Duodenum9 (descending Rectum (middle third11), 
and transverse), Vagina12 (upper part), 
Ascending colon, Bladder13 (posterior surface). 
Descending colon, 
(3) Rectum11 (lower third), Pancreas19, 
Bladder13 (base, Kidneys, 
anterior surface), Suprarenal capsules, 
Vagina (lower portion). THE LARYNX. 
249 
ORGANS OF VOICE AND RESPIRATION. 
The Larynx. 
What is the larynx1 (Fig. 92) ? 
The voice-organ, formed of cartilages united by ligaments, the 
segments enjoying movement upon one another, which is effected 
by numerous muscles. 
Mention the component cartilages 
They are nine in number, being the 
Thyroid cartilage\ 
Cricoid cartilagei, 
Epiglottis, 
Two arytenoid cartilages,'' 
Two cuneiform cartilages, 
Two cornicula laryngis. 
Describe the thyroid (shield-like) cartilage. 
It consists of two alee1, or lamellse, 
united at an acute angle in front, forming 
a vertical ridge1, whose more prominent 
upper portion is called the pomum 
Adamix, or Adam’s apple; the 
Inner surfaces of the alse are smooth, 
giving attachment in front, at the reced- 
ing angle formed by their junction, to 
epiglottis, true and false vocal cords, 
thyro-arytenoid and thyro-epiglottidean 
muscles. 
The outer surface affords attachment 
along an oblique ridge to sterno-thyroid 
and thyro-hyoid muscles, below and be- 
hind to inferior constrictor muscle. 
The upper border presents a deep, 
medium notch1, and is slightly concave 
on either side. 
The lower border is connected medianly with cricoid cartilage 
by crico-thyroid membrane, and on each side by crico-thyroid 
muscle. 
Fig. 91. 250 
ESSENTIALS OF HUMAN ANATOMY. 
The posterior borders are thick, rounded, and terminate above 
and below on each side in cornua, the two superior3 having attached 
to their apices the thyro-hyoid ligament, while the inferior4 articu- 
late internally by an oval facet with cricoid cartilage; to this 
border are also attached the stylo-pharyngeus and palato-pharyn- 
geus muscles. 
Describe the cricoid (ring-like) cartilage. 
It is placed with its narrow portion6 in front, and has on each 
side two articular facets, one on upper margin behind for arytenoid 
cartilages, one externally, near lower margin for inferior cornu of 
thyroid cartilage. 
The upper border gives attachment in front and at sides to crico- 
thyroid membrane, at sides to lateral crico-arytenoid muscles. 
The lower border is connected with first tracheal ring by a fibrous 
membrane. 
The posterior surface presents a median vertical ridge for attach- 
ment of longitudinal fibres of oesophagus, and on either side the 
posterior crico-arytenoid muscles are attached. 
Describe the two arytenoid (pitcher-like) cartilages7. 
They are pyramidal in form, and are placed at the upper border 
of cricoid cartilage at back of larynx; the 
Posterior surface of each affords attachment to arytenoideus 
muscle; the 
Anterior surface of each has attached the thyro-arytenoid muscle 
and false vocal cord; the 
Internal surfaces face each other ; the 
Base presents a concave, smooth, articular facet for cricoid carti- 
lage ; the 
External angle has attached to it the posterior and lateral crico- 
arytenoid muscles; the 
Anterior angle has attached to it true vocal cord ; the 
Apex articulates with a corniculum laryngis. 
Describe the cornicula laryngis. 
They are two small conical cartilaginous nodules surmounting 
the apices of arytenoid cartilages affording attachment to aryteno- 
epiglottidean folds. THE LARYNX. 
251 
Describe the two cuneiform cartilages. 
They are elongated cartilages contained in free borders of aryteno- 
epiglottidean folds. 
Describe the epiglottis. 
It is a thin, leaf-shaped lamella of fibro-cartilage, attached by 
apex to reentering angle of thyroid cartilage just below median 
notch; it lies at base of tongue, in front of upper opening of 
larynx, and during deglutition shuts like a lid over laryngeal 
orifice. Its 
Base is free, rounded, curving forward toward base of tongue; 
the 
Apex is attached to receding angle of thyroid by thyro-epiglottic 
ligament; the 
Anterior surface is covered with mucous membrane reflected on 
to sides and base of tongue, forming the three glosso-epiglottidean 
ligaments; the 
Posterior surface shuts down over laryngeal opening during deg- 
lutition ; the 
Lateral margins give attachment to aryteno-epiglottidean folds. 
How are the ligaments of the larynx divided ? 
Into extrinsic, or those connecting thyroid cartilage and epiglottis 
with hyoid bone; and intrinsic, those binding the various cartilages 
together. 
Name the extrinsic ligaments. 
Thyro-hyoul membrane, Two lateral thyro-hyoid ligaments, 
containing a small cartilaginous or bony nodule, the cartilago 
triticea; Hyo-epiglottic. 
Name the intrinsic ligaments 
Orico-thyroid membrane, 
Two crico-thyroid capsular liga- 
ments, 
Two crico-arytenoid ligaments, 
Two crico-arytenoid capsular 
ligaments, 
Two inferior thyro-arytenoid liga- 
ments, 
Hyo-epiglottic ligament, 
Thyro-epiglottic ligament, 
Three glosso-epiglottic folds, 
Two superior thyro-arytenoid 
ligaments. 252 
ESSENTIALS OF HUMAN ANATOMY. 
What are the vocal cords ? 
The superior or false vocal cords, on each side, are two folds of 
mucous membrane enclosing the superior thyro-arytenoid ligaments 
composed of elastic tissue, stretching between angle of thyroid 
cartilage below epiglottis and anterior surfaces of arytenoid carti- 
lages ; the lower margin forms the upper free crescentic margin of 
ventricle of larynx. 
The true, or inferior vocal cords, are two strong, yellow elastic 
fibrous tissue bands, the inferior thyro-arytenoid ligaments, covered 
by thin, tightly adherent mucous membrane, which pass from the 
receding angle of the thyroid to anterior angles of arytenoid carti- 
lages, the upper border forming the lower margin of ventricle of 
larynx, the lower continuous with lateral portion of crico-thyroid 
membrane; each has the thyro-arytenoid muscle lying parallel 
externally; these cords or membranes produce sound by their vibra- 
tions, the false cords do not, although indirectly influencing vocali- 
zation. 
What is the glottis (rima glottidis) ? 
It is the narrow triangular interval between the true vocal cords; 
it measures, in males, somewhat less than an inch, by from one- 
third to one-half inch at its base behind, when dilated. 
Describe the ventricle of the larynx. 
It consists of an oval depression or sinus on each side, between 
the true and false vocal cords leading upward, external to superior 
cord, into a csecal pouch, the sacculus laryngis. 
Describe the sacculus laryngis. 
It is a slightly curved conical membranous sac, situated between 
the inner surface of thyroid cartilage and false vocal cords on each 
side; internally lined with mucous membrane, perforated by orifices 
of ducts of sixty to seventy follicular glands lying in the submu- 
cous tissue; it is strengthened externally by a fibrous capsule con- 
tinuous below with superior thyro-arytenoid ligament, and has its 
inner (laryngeal) surface covered by the inferior thyro-arytenoi- 
deus, and its external by thyro-epiglottideus muscles, which com- 
press the sacculus, discharging the mucus upon, and for the lubri- 
cation of the vocal cords. THE LARYNX. 
What kind of epithelium has the mucous membrane ? 
Above the false vocal cords squamous epithelium is found, except 
in front, which is covered by ciliated columnar cells as high as 
middle of epiglottis; below the false cords, only ciliated columnar 
epithelium is found. 
Describe the muscles of the larynx and epiglottis. 
Crico-thyroid2 (2) (Fig. 92): origin, triangular from antero-lateral 
surface of cricoid cartilage; insertion, lower border of thyroid and 
anterior border of lower cornu; action, increases tension of vocal 
cords by tilting thyroid cartilage forward; nerve, superior laryngeal. 
Crico-arytenoideus posticus (2): origin, lateral half of posterior 
surface of cricoid; insertion, outer angle of base of arytenoid carti- 
lage ; action, by rotating arytenoid cartilages outward it opens 
glottis and tightens cords ; nerve, recurrent laryngeal. 
Crico-arytenoideus lateralis (2): origin-, upper border of side of 
cricoid; insertion, outer angle of base of arytenoid; action, by 
rotating arytenoids inward closes glottis; nerve, recurrent laryngeal. 
Thyro-arytenoideus (2): origin, lower half of receding angle of 
thyroid and crico-thyroid membrane ; insertion, base and front sur- 
face of arytenoid cartilage; action, advances arytenoid and cricoid 
cartilages thus relaxing vocal cords, also compresses sacculus laryn- 
gis; nerve, recurrent laryngeal. 
Arytenoideus (1): origin, back surface and outer border of one 
arytenoid to be inserted at same part of other cartilage; action, ap- 
proximates arytenoids closing back of glottis; nerves, superior 
and recurrent laryngeal. 
Kerato-cricoideus: a small muscular bundle; origin, from near 
lower border of cricoid cartilage; insertion, inferior cornu of thy- 
roid cartilage; action, possibly steadies one cartilage upon the 
other, only occasionally found, and usually on one side. 
Triticeo-glossus : origin, cartilage of same name in lateral thyro- 
hyoid ligament; insertion, tongue with hyo-glossus muscle; occurs 
on one or both sides; action, unknown. 
Describe the muscles of the epiglottis. 
Thyro-epiglottideus: origin, inner surface of thyroid cartilage; 
insertion, aryteno-epiglottidean fold, margin of epiglottis, outer sur- 254 
ESSENTIALS OF HUMAN ANATOMY. 
face of sacculus laryngis ; action, depresses epiglottis; nerve, recur- 
rent laryngeal. 
Aryteno-epiglottideus superior : origin, apex of arytenoid cartilage; 
insertion, aryteno-epiglottidean folds ; action, narrows upper laryn- 
geal orifice; nerve, recurrent laryngeal. 
Aryteno-epiglottideus inferior: origin, arytenoid cartilage above 
superior vocal cord; insertion, inner upper part of epiglottis; 
action, compresses sacculus laryngis; nerve, recurrent laryngeal. 
Mention the arteries and veins of the larynx. 
The arteries, are laryngeal branches of superior and inferior 
thyroid arteries, which inosculate freely ; the 
Veins, empty into superior, middle, and inferior thyroid veins. 
What nerves supply the larynx ? 
The superior, and inferior or recurrent laryngeal, branches of 
pneumogastric, the former receiving branches from spinal acces- 
sory and superior cardiac sympathetic nerves ; the 
Superior laryngeal is chiefly a nerve of sensation, supplying laryn- 
geal mucous membrane and arytenoid muscles by its internal 
laryngeal branch, after piercing the thyro-hyoid membrane; and 
the crico-thyroid muscle by its external laryngeal branch; the 
Recurrent larxjngeal is the motor nerve supplying all the laryn- 
geal muscles except crico-thyroid-, the right nerve descends the 
neck to pass from before backward around the subclavian artery, 
the left winds in the same direction around the aortic arch, and 
both nerves ascend in groove between trachea and oesophagus to 
their distribution, giving off in their course cardiac, oesophageal, 
tracheal, and pharyngeal branches, and anastomosing with superior 
laryngeal nerves. 
The Trachea and Bronchi. 
What is the trachea3 (Fig. 92)? 
It is a membranous, cylindrical air-tube, flattened posteriorly, 
of a transverse diameter of three-quarters to one inch, extending 
from lower part of larynx (corresponding to sixth cervical vertebra), 
to opposite fourth or fifth dorsal vertebra, where it bifurcates to 
form the THE TRACHEA AND BRONCHI. 
255 
Right and left bronchus; it is composed of sixteen to twenty imper- 
fect cartilaginous rings surrounding two-thirds of the cylinder, 
enclosed in a double elastic fibrous membrane connecting the rings 
with one another, while the space behind has, in addition to the 
membrane—there forming a single layer—a layer of longitudinal 
and another of transverse unstriped muscular fibres, the transverse 
lying beneath the fibrous membrane called the trachealis muscle; the 
last ring, by a triangular hooked-process curving backward between 
the bronchi, forms two imperfect rings on either side for right and 
left bronchus; the lining mucous membrane contains much lym- 
phoid tissue and numerous glands, and is covered by several 
layers of epithelium, the most superficial columnar ciliated. 
Give the relations of the trachea in the neck. 
It is covered in front from above downward by 
Anastomosing branches 
between jugular veins, 
Isthmus of thyroid gland 
Inferior thyroid veins, 
Arteria thyroidea ima 
(when present), 
Ster'no hyoid muscle, 
Stero-thyroid muscle, 
Posteriorly, it lies upon 
(Esophagus, 
Laterally, lie 
The common carotid 
arteries13, 
Lobes of thyroid gland, 
Inferior thyroid arteries, 
Recurrent laryngeal nerves. 
Describe its relations in the thorax. 
It is covered from before backward by 
Manubrium of sternum, 
Remains of thymus gland, 
Left innominate vein, 
Arch of aorta, 
Innominate artery, 
Left carotid artery12, 
Deep cardiac plexus. 
Posteriorly, lies the 
(Esophagus, 
Laterally, on each side, the 
Pneumogastric nerves, 
What are the bronchi ? 
Two tubes, structurally like trachea, extending from its bifurca- 
tion into the lungs, dividing and subdividing to form the bron- 
chial tubes, in whose walls only scattered cartilaginous plates 
exist until the diameter of one-fourth of a line is reached, when 256 
ESSENTIALS OF HUMAN ANATOMY. 
they become wholly membranous, while the muscular coat and 
elastric fibrous coat then form a continuous circular layer around 
the smallest tubes; the mucous membrane is covered with ciliated 
columnar epithelium; the 
Right bronchus is wider, shorter (about one inch long), and 
more horizontal than left; the 
Left bronchus is smaller, more oblique, and longer (nearly two 
inches). 
Describe the relations of each bronchus. 
The right, beginning opposite fourth dorsal, enters lung opposite 
fifth dorsal vertebra, lying behind superior vena cava and right 
auricle of heart, having the right pulmonary artery at first below, 
then anterior to it, and the vena azygos major arching over it 
from behind. 
The left bronchus, commencing at same point as right, passes in 
front of (esophagus, thoracic duct, and descending aorta beneath 
the aortic arch, the left pulmonary artery lying at first above, 
then in front of it to enter lung opposite sixth dorsal vertebra. 
What vessels and nerves supply trachea and bronchi ? 
The arteries are tracheal branches of inferior thyroid arteries and 
bronchials from aorta; the 
Veins empty into thyroid plexus and bronchial veins; the 
Lymphatics empty into mediastinal glands ; the 
Nerves are branches from pneumogastric, recurrent laryngeal 
branch of same, and sympathetic nerve. 
The Lungs. 
Describe them. 
They are the two organs of respiration, occupying the greater 
part of the thoracic cavity, separated by the heart and other contents 
of the mediastinum, covered by the pleurae, of a specific gravity 
of 0.345 to 0.746, weighing together about forty-two ounces, the 
right being the heavier by two ounces. They are pinkish-white 
at birth, but irregularly marked by slate-colored patches as age 
advances from the deposit of carbonaceous matter, or perhaps 
altered blood-pigment, in the lung tissue; they are divided into THE LUNGS. 
257 
lobes, the right lung having three4,5,6, the left only two7,8; each 
lung has an 
Apex, extending into root of neck beneath and above first rib, 
about one to one and a half inches, where it is in contact with 
first and second part of subclavian artery; the 
Fig. 92; 
Base is broad and concave, resting upon diaphragm, its thin 
margins extending lower down externally and behind than in 
front; the 
External surface is smooth, convex, marked by the interlobular 
fissures, and conforms to the shape of the thorax; the 
Inner surface is concave, and the left lung presents a depression 
in front for heart; behind, each has a deep fissure, the hilum 
pulmonis, the point of attachment of root of lung; the 258 
ESSENTIALS OF HUMAN ANATOMY. 
Boot21 is the point of entrance of bronchus, pulmonary and 
bronchial arteries, and of exit of the pulmonary and bronchial 
veins and lymphatics ; in front of each lies the phrenic nerve and 
anterior pulmonary plexus, behind, the pneumogastric and pos- 
terior pulmonary plexus. 
In what order are these various structures arranged ? 
From before backward, 
Pulmonary veins, 
Pulmonary artery, 
Bronchus, etc. 
may be recalled by letters 
V, A, B. 
From above downward ; right lung, 
to be recalled by letters, 
Bronchus, 
Pulmonary artery. 
Pulmonary veins. 
B, 
A, 
V. 
Left lung, 
Pulmonary artery, 
Bronchus, etc., 
Pulmonary veins. 
to be recalled by letters, 
A, 
B, 
V. 
Describe the structure of the lung. 
They have externally a serous coat, a subserous areolar tissue 
penetrating between the lobules, and their bulk is composed of the 
pulmonary substance or parenchyma, which is formed of an aggre- 
gation of lobules, each composed of a terminal bronchial tube with 
its air cells, and ramifications of pulmonary and bronchial vessels, 
lymphatics, and nerves, thus forming a miniature of lung; they 
are pyramidal and large upon the surface, smaller and irregular in 
the interior; the alveoli, or air-cells, are small polyhedral alveolar 
recesses measuring about one-two-hundredths to one-seventieth of 
an inch, opening into the sides and ends of the intercellular passages 
—i.e., the irregular terminations of the bronchioles—separated 
from one another by delicate membranous septa, between the layers 
of which lies the plexus formed by the pulmonary artery, thus ex- 
posing the blood to air on two surfaces; they are lined with a layer 
of squamous epithelium. THE PLEURJ. 
259 
What are the vessels and nerves of the lungs ? 
They receive blood by bronchial arteries for their own nutrition, 
and venous blood by pulmonary artery for aeration, i. e , absorption 
of oxygen and emission of carbonic dioxide; the vessels are 
Bronchial arteries, branches of aorta. Pulmonary arteries, from 
right side of heart. The bronchial veins empty on right side into 
the vena azygos, on the left, into superior intercostal vein ; the 
Lymphatics empty into bronchial glands ; the 
Nerves are derived: from the anterior and posterior pulmonary 
plexuses, formed chiefly by branches from the sympathetic and 
pneumogastric nerves. 
The Pleurae. 
What are the pleurae ? 
Two closed delicate serous sacs, consisting of a portion investing 
each lung and another lining, respectively, the right and left halves 
of thorax. 
Are the pleurae in contact internally ? 
No, except at one point in front, leaving a space between them 
elsewhere. 
What is the visceral layer (that covering lung) of each 
pleura called? 
The joleura pulmonalis, investing the lung as far as its root, 
What is that called which lines the thorax ? 
Pluera costalis. or parietal layer. 
What is the ligamentum latum pulmonis ? 
This broad ligament of the lung is a triangular fold of the pleura 
passing downward from lower border of root of lung to diaphragm, 
retaining lower part of lung in position. 
Do the pleural cavities differ from each other ? 
Yes, the right is shorter, wider, and extends higher in neck. 260 
ESSENTIALS OF HUMAN ANATOMY. 
What is the mediastinum ? 
The median space left between the two pleural sacs, extending 
from sternum to vertebral column, containing all the thoracic vis- 
cera but lungs. 
Mention its subdivision, and the contents of each. 
The anterior mediastinum, bounded in front by sternum, on each 
side by pleurae, and behind by pericardium ; its contents are 
Origins of sterno-hyoid and sterno-thyroid muscles, 
Origin of triangularis sterni muscle, 
Left internal mammary vessels, 
Remains of thymus gland, 
Loose areolar tissue containing lymphatics. 
The middle mediastinum is the broadest portion of interpleural 
space; its contents are the 
Heart enclosed in the pericardium, 
Ascending aorta, 
Superior vena cava, 
Bif urcation of trachea, 
Pulmonary artery, 
Pulmonary vein, 
Phrenic nerves. 
The posterior mediastinum, bounded in front by pericardium and 
roots of lungs, behind by spinal column, and laterally by the 
pleurae; its contents are the 
Descending aorta, 
The greater azygos vein, 
The lesser azygos vein, 
Left superior intercostal vein, 
Pneumogastric nerves, 
Splanchnic nerves, 
(Esophagus, 
Thoracic duct, 
Lymphatic glands. 
The Urinary Organs. 
Where are the kidneys situated ? 
In tlie lumbar regions, one on each side of the vertebral column 
each kidney reaching from the eleventh rib nearly to the iliac crest, 
but the right a little lower than the left; they lie embedded in a 
mass of fat behind the peritoneum, which retains them in place 
with the aid of their bloodvessels. THE URINARY ORGANS. 
261 
What are their size and weight ? 
Each measures about four inches in length, two in breadth, and 
one inch in thickness; they weigh, in the male, from four and a 
half to six ounces; in the female, four to five and a half ounces. 
Describe their relations. 
The Anterior surface of right kidney is in relation with the right 
lobe of liver, descending portion of duodenum, and ascending colon. 
The Anterior surface of left kidney, with great end of stomach, 
lower end of spleen, tail of pancreas, and descending colon. 
The Posterior surface of each rests upon crus of diaphragm, the 
anterior lamellae of transversalis aponeurosis separating it from 
quadratus lumborum and psoas magnus. 
The Superior extremity is embraced by the suprarenal capsule. 
What is the hilum of the kidney ? 
A notch or fissure one inch long at central portion of internal 
border, opening into a cavity, the sinus; through it pass the 
lymphatics; the renal vein is in front; the renal arteryA next, and 
ureteru, or excretory duct, behind and below. 
Describe the naked-eye appearances of a vertical section 
of a kidney. 
The kidney proper consists of a 
Cortical structure1, composed of convoluted and straight urinifer- 
ous tubules, bloodvessels, nerves, lymphatics, connective tissue, 
and Malpighian bodies, and is prolonged down between the pyra- 
mids, forming the columns of Berlin; a fibrous capsule envelops 
the organ, passes into the sinus which it lines, blending with the 
sheaths of vessels, nerves, and the calices ; the 
Medullary substance2 consists chiefly of straight tubuli uriniferi, 
“ looped tubes of Henle ”, bloodvessels, etc., arranged in eight to 
eighteen 
Pyramids of Malpighi2, whose apices are embraced by the calices 
of the pelvis; the 
Pelvis consists of from seven to eighteen calicesc, cup-like tubes, 
embracing the apices of one or more Malpighian pyramids, con- 
verging to form three infundibula, these again joining to form the 
pelvisc, which gradually contracts into the ureterU or excretory duct. 262 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the tubuli uriniferi15 (Fig. 94). 
They commence in a dilated caecal extremity, the Malpighian1 
capsule and terminate by opening on the free surface of the 
papillae15. They are called, in various portions of their course, the 
Fig. 93. 
Proximal convoluted tube*, the much convoluted portion after 
leaving the Malpighian capsule and situated in the cortical portion. 
The spiral tube of Schachowa4, next succeeding, where the tube 
approaches the medullary portion in a spiral manner; now enter- 
ing the medullary portion, the tubes suddenly become smaller, THE URINARY ORGANS. 
263 
quite straight, dipping down into the pyramids to ascend, suddenly 
enlarge, and again become spiral, and reenter the cortical structure, 
constituting the descending 
Loop of Ilenle3, this ascends7,8 in an irregular angular manner 
through the cortex, and terminates in the 
Distal convoluted tube'0,11, which terminates in a narrow 
Curved tube12, continuous with a 
Straight, or collecting tube13,1*, terminating on summit of one of 
the papillae. 
Describe these straight tubes13,14- 
Traced into pyramids from the papillae, they run from apex to 
base, dividing diehotomously, receiving the curved tubes, to enter 
the cortex much increased in number, where they form conical 
masses with their bases toward the medullary portion. 
What are these conical masses called ? 
The pyramids of Ferrein. 
Describe the epithelium of the uriniferous tubules. 
It varies in different portions, being flattened polyhedral, angular, 
and columnar. 
Describe the Malpighian bodies (tufts, or vascular 
glomeruli). 
Each is formed by a renal afferent* (Fig. 95) arteriole, which, after 
piercing the capsule—a pouch-like commencement of a tubulus 
uriniferus lined with flattened epitheliumk—breaks up into a tuft 
of vessels forming a plexusc, from which arises the efferente vessel 
emerging from capsule near point of entrance of afferent arteriole. 
Describe the renal circulation. 
The 
Renal artery, from aorta, divides just external to hiluin, into 
four or five 
Primary branches, which divide and subdivide to form 
Arteries proprice renales, two of which run along the sides of each 
Malpighian pyramid, giving off afferent branches to Malpighian 
bodies in columns, and, bending between bases of pyramids and 
cortex, send off the (1) interlobular, and (2) arteriolse rectse; 264 
ESSENTIALS OF HUMAN ANATOMY. 
(1) Interlobular arteries, passing outward between the pyramids 
of Ferrein to capsule, terminating in stellate plexuses beneath it 
(stars of Verheyen), and also supplying afferent arterioles to Mal- 
pighian bodies of cortex, whence issue efferent vessels forming a 
dense venous plexus around adjacent uriniferous tubules; and the 
Fro. 94. 
Subcapsular layer 
without Malpighian 
corpuscles. 
Cortex. 
Inner stratum of cortex, without 
Malpighian corpuscles. 
(2) Arterioles rectae, or descending branches, passing from bases to 
apices of pyramids, there to terminate in the venous plexuses. 
The blood is collected by the stellate venous plexuses beneath the 
capsule, forming verne interlobulares, which pass between pyramids 
of Ferrein, are joined by branches emptying the plexuses around 
convoluted tubes of cortex , and join the venae rectae at bases of 
Malpighian bodies; these venae rectos being branches from plexuses 
at apices of medullary pyramids formed by arteriolae rectae. The THE URETERS. 
265 
junction of the venae rectce and venae interlobulares form the venae, 
proprice renales, accompanying the arteries of the same name, 
which receive venous twigs from Malpighian bodies of medulla 
and unite in the sinus to form the 
Renal, or emulgent vein, which passes out of hilum to empty into 
inferior vena cava, the right vein being the shorter. 
Fig 95. 
Describe the nerves of the kidney 
They are small, fifteen in number, have ganglia developed upon 
them, and come from the solar plexus, lower and outer part of 
semilunar ganglia, and from lesser and smallest splanchnic nerves 
forming the rmat jplexus, communicating with spermatic plexus. 
The Ureters. 
What is the ureter ? 
It is the tubular, cylindrical, excretory duct of the kidney, of 
the size of a goose-quill, sixteen to eighteen inches long, extend- 
ing from the pelvis of kidney to base of bladder, into which it 
opens by a constricted orifice, after having passed obliquely for 
nearly an inch between its muscular and mucous coats: it has a 
fibrous coat continuous with capsule of kidney and fibrous tissue 266 
ESSENTIALS OF HUMAN ANATOMY. 
of bladder, a muscular composed of longitudinal and circular 
fibres, a mucous covered with several layers of many shaped epithe- 
lial cells. 
Describe its course and relations. 
It passes obliquely downward along posterior abdominal wall 
beneath the peritoneum, over the iliac arteries, behind ilium on 
right side, and sigmoid flexure on left, enters the posterior false 
ligament of bladder in male, with vas deferens between it and 
bladder, and enters bladder obliquely (see supra) about one and 
one-half inches behind prostate, and two inches from its fellow, 
at posterior angle of trigone; in female it passes along sides of 
cervix uteri and upper part of vagina; the right ureter lies close 
to outer side of vena cava. 
The Bladder. 
What is the bladder1 ? 
The musculo-membranous reservoir for the urine, situated be- 
hind the pubes, between it and rectum in male, between the pubes 
and uterus in female; when moderately distended its dimensions 
are, length five inches, breadth three inches, capacity about one 
pint; in the child it is an abdominal organ, and also in adults 
when distended. It presents for examination, the 
Summit10 (Fig. 98), connected with umbilicus by a fibro-mus- 
cular cord, the urachus, and by two fibrous cords placed on either 
side, the obliterated foetal hypogastric arteries; the 
Body lies against posterior surface of pubes, triangular liga- 
ment, internal obturator muscles, and—when distended—abdom- 
inal walls, its posterior surface being covered by peritoneum, 
having some coils of small intestine interposed between it and 
rectum, and uterus in female ; the obliterated hypogastric arteries 
cross its sides obliquely from below, upward and forward, all 
below them being uncovered with peritoneum; the vas deferens 
curves from before backward along each side to reach the base of 
bladder passing across the obliterated hypogastric vessels and 
along inner side of ureter; the THE BLADDER. 
267 
Fundus, or base11 (Fig. 98), is directed downward and back- 
ward, resting in the male upon the second portion of rectum, in 
the female upon lower part of cervix uteri, being adherent to 
upper part of vagina, but separated 
from cervix by a fold of peritoneum 
which is reflected so as to cover a 
small portion of base; in male the 
peritoneum passes from rectum to same 
portion of base; the 
Neck, or cervix12 (Fig. 98), is the 
constricted portion continuous with 
urethra, surrounded in male by pros- 
tate gland, and is directed downward 
and forward. 
How is the bladder held in place ? 
By true and false ligaments; the true, 
being the 
Anterior, or pubo-prastatic, formed by two folds of the recto- 
vesical fascia extending from either side of pubic symphysis to 
front of cervix over upper surface of prostate gland ; the 
Lateral, of same tissue, passing between lateral surfaces of 
prostate gland on each side, and sides of base of bladder; the 
Urachus22 (Fig. 98), a fibro-muscular cord covered with perito- 
neum, stretching between apex of bladder and umbilicus. 
The false ligaments are, 
Two Posterior, folds of peritoneum passing, in male from sides 
of rectum, in female from sides of uterus, to postero-lateral aspect 
of bladder, and contain the obliterated hypogastric arteries, the 
ureters, vessels, and nerves. 
Two lateral, peritoneal folds passing from iliac fossa to sides of 
bladder. 
Superior23 (Fig. 98), a peritoneal fold passing over urachus and 
obliterated hypogastric arteries from apex of bladder to umbilicus. 
What is the urachus22 (Fig. 98) ? 
The remains of a tubular canal connecting bladder with allan- 
tois in foetus. 
Fig. 96. 268 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the structure of the bladder 
It has four coats, viz., a 
Peritoneal23,24 (Fig. 98), covering posterior surface from entrance 
of ureters at base to its summit, passing on to sides whence it is 
reflected to abdominal and pelvic walls: a 
Muscular, consisting of fibres spirally arranged forming figure- 
of eight loops, the more superficial being nearly longitudinal, the 
deeper nearly circular, corresponding to same-named layers of 
older authors; these form seven more or less distinctly marked 
layers, the loops directed toward, and embracing the urachus and 
urethra respectively, the aggregation of these loops around the 
neck forming the sphincter and the fibres passing in all directions 
are continued into prostatic urethra (Pettigrew): a 
Cellular, which is a layer of areolar tissue intimately blended 
with mucous membranes binding it to the muscular coat; a 
Mucous coat, covered by transitional epithelium, the superficial 
layer of polyhedral cells, below club-shaped and smaller spindle- 
celled : it contains a few mucous follicles 
and numerous racemose glands lined with 
columnar epithelium near the neck; it 
is thrown into folds or rugae when blad- 
der is empty. 
What are the muscles of the ure- 
ters ? 
Two oblique bands rising behind the 
orifices of the ureters which converge, to 
be inserted by a fibrous process into the 
middle lobe of prostate gland. 
What is the trigonum vesicae or 
trigone vesical2 (Fig. 97)? 
A triangular smooth surface at base of 
. bladder, with apex forward, of a paler 
color than remainder of mucous mem- 
brane, which is intimately adherent to 
subjacent tissues: the 
Lateral boundaries are two slightly 
marked ridges on each side passing backward and outward from 
Fin. 97. THE MALE URETHRA. 
269 
the apex formed by urethral opening to orifices of ureters3, cor- 
responding to the muscles of these ducts, the openings being placed 
about two inches from one another and one and a half inches 
behind urethral opening, a line connecting the two forming the 
base of the trigone. 
What is the uvula vesicse4 (Fig. 97) ? 
A slight elevation of the mucous membrane projecting from 
lower anterior portion of floor of bladder into orifice of urethra. 
Mention the arteries supplying the bladder. 
Superior, middle and inf erior vesical, and small twigs from obturator 
and sciatic arteries in male, with additional branches from uterine 
and vaginal, in female: the veins form intricate plexuses around 
neck, sides, and base, emptying into internal iliac vein ; the 
lymphatics accompany the vessels. 
Give the nerve-supply of the bladder. 
Branches from hypogastric plexus of sympathetic supply upper 
part, and the third and fourth sacral nerves the base and neck. 
The Male Urethra. 
Describe this canal. 
It extends from neck of bladder4 to meatus urinarius, measuring 
from eight to nine inches, presenting a double curve when penis is 
flaccid, but a single one with convexity downward during erection. 
Name and describe each of its divisions. 
They are the prostatic7,8, membranous, and spongy. 
The prostatic, portion7,8 (Fig. 97) is that portion passing from base 
to apex of prostate gland, running nearer the upper surface, measur- 
ing one and a quarter inches long, is the widest and most dilatable 
section of urethra and is spindle-shaped; upon the median aspect 
of the floor is a narrow longitudinal ridge eight to nine lines long, 
the verumontanum or caput gallinaginis5 (Fig. 97) containing mus- 
cular and erectile tissue: on either side is a slight fossa, its floor 
presenting the numerous openings of the prostatic ducts, called the 
prostatic sinus. 270 
ESSENTIALS OF HUMAN ANATOMY. 
The sinus pocularis, or uterus masculinus6 (Fig. 97), is a depression 
extending about a quarter of an inch upward and backward be- 
neath middle lobe of prostate in the median line at fore part of 
verumontanum, upon or within whose margins are the slit-like 
orifices of the seminal or ejaculatory ducts6 (Fig. 97). 
The membranous portion9- (Fig. 97) is that portion, three-quarters 
of an inch long, extending between apex of prostate and bulb of 
corpus spongiosum, which is included between the layers of the 
triangular ligament about one inch beneath the pubic arch ; it is 
surrounded by the compressor urethrae muscle, and is the narrowest 
portion of urethra, except meatus. 
The spongy portiond>h (Fig. 97) is the longest measuring about 
six inches, is so called from being contained in the corpus spongio- 
sum, extends from membranous portion to meatus urinarius, and 
presents a posterior dilatation, that of the bulb8 (Fig. 98), and one 
Fig. 98. 
anterior, the fossa navicufaris16 (Fig. 98), the former having opening 
into it the ducts of Covvper’s glands, the latter fossa being situated 
within the glans penis, having an opening directed forward in its 
roof, the 
Lacunus magnus, the orifice of a large mucous crypt; there are also 
here numerous other scattered openings of glands similarly directed. 
What is the meatus urinarius ? 
The anterior orifice of the urethra, a vertical slit about three FEMALE URETHRA. 
271 
lines long bounded on each side by a small labium, and is the nar- 
rowest portion of the canal. 
It possesses three coats, viz., a mucous, forming a part of the 
genito-urinary membrane internally and continuous with the skin 
externally, having numerous mucous glands imbedded in its sub- 
mucous tissue, which open on its free surface, and is covered with 
columnar epithelium except near meatus where it is squamous. 
The muscular coat consists of longitudinal fibres externally, 
circular within, the latter lying beneath urethral mucous mem- 
brane for its whole length, the former leaving the circular fibres at 
the bulb to envelop the spongy body beneath its fibrous coat, again 
rejoining the circular fibres at the meatus urinarius; both mus- 
cular layers are in direct continuity with those of bladder. (For 
voluntary urethral muscles see p. 331.) 
Erectile, this is a thin layer of erectile tissue surround ipg the mem- 
branous and prostatic portions, anteriorly becoming continuous 
with that of corpus spongiosum. 
Describe the structure of the urethra. 
Female Urethra. 
Describe this canal. 
It is about one and one-half inches long, extends from bladder to 
meatus urinarius above anterior vaginal wall, pierces the triangular 
ligament, and is embraced by compressor urethrae muscle as in 
male: its structure is similar to that of male urethra, it is lined by 
laminated squamous epithelium merging into spheroidal near blad- 
der, is a quarter of an inch in diameter, but is capable of much 
greater dilatation; and its anterior opening (meatus) is situated 
near anterior margin of vagina, about one inch below clitoris, sur- 
rounded by a prominence of mucous membrane. 
The Male Generative Organs. 
Where is the prostate gland situated9 (Fig. 97)? 
It surrounds neck of bladder and commencement of urethra, 
lying in pelvic cavity posterior to deep perineal fascia, behind and 272 
ESSENTIALS OP HUMAN ANATOMY 
below symphysis pubis upon the rectum: through it pass the 
urethra and seminal ducts. 
Describe its form and size. 
It resembles a horse-chestnut in form, measures one and a half 
inches transversely, one inch antero-posteriorly, three-quarters of an 
inch in depth, and weighs about six drachms: the base is directed 
backward toward bladder: it consists of two equal- sized lateral 
lobes and a middle lobe, a small transverse band or rounded 
triangular eminence placed between lateral lobes immediately 
beneath neck of bladder behind commencement of urethra. 
Describe its structure ? 
It is composed of numerous follicular pouched glands opening 
into elongated canals which join to form twelve to twenty excre- 
tory ducts imbedded in the interstices of a stroma formed of inter- 
lacing bundles of unstriped muscle, the whole being inclosed in a 
fibrous capsule. 
What retains the gland in place ? 
The pubo-prostatic ligaments of bladder, posterior layer of deep 
perineal fascia, and anterior portion of levator ani muscle. 
Describe the situation and structure of Cowper’s glands ? 
They are two small lobulated glands of the size of peas, lying 
between the two layers of the deep perineal fascia in front, close 
behind bulb of urethra, surrounded by compressor urethrae muscle 
and opening, by ducts one inch long which pass obliquely forward 
beneath mucous membrane, on the floor of bulbous portion of 
urethra. 
Describe the penis ? 
The Penis. 
It has a root, body5 (Fig. 98), and extremity or glans penis6, and 
consists of three elongated cylindrical masses of erectile tissue, 
composed of a fibrous sheath which sends inward numerous inter- 
lacing bands (trabeculae) forming numerous meshes in which lie 
the bloodvessels. The upper two cylindrical bodies lying side by THE PENIS. 
side, like a double-barrel gun, are called the corpora cavernosa5; 
the third, much smaller, lying in median line beneath, like the 
ramrod of a gun, is the corpus spongiosum7. 
Describe the corpora cavernosa. 
Situated as just described, they are intimately connected in their 
anterior three fourths where they are in contact, presenting a 
median dorsal groove for vessels and nerves, an inferior median 
one for corpus spongiosum, while their posterior fourth diverges, 
forming the crura*, which are attached to the rami of pubes and 
ischium anterior to the tuberosity; near their point of junction 
with one another they become slightly enlarged, forming, on either 
side, the bulb of the corpus cavernosum. 
What other structure besides the crura secures the root of 
the penis to symphysis pubis ? 
The suspensory ligament, a fibrous membrane. 
What is the septum pectiniforme5 ? 
The anterior portion of the vertical fibrous septum which is in- 
complete, the fibrous bands resembling in their arrangement the 
teeth of a comb; the septum and fibrous sheath contain numerous 
elastic and muscular fibres in addition to the white fibrous tissue. 
Describe the corpus spongiosum. 
It incloses the urethra15, lying medianly below at junction of 
corpora cavernosa, commencing behind in front of deep perineal 
fascia between the crura of the corpora cavernosa as a rounded 
enlargement, the bulb8, which is surrounded by the accelerator 
urinse muscle. Anteriorly it forms a conical enlargement, flatten- 
ing from above downward, which caps the blunted end formed by 
the corpora cavernosa, the glans penis6, the margin of whose base 
is called the corona glandis, the constriction behind the cervix. 
What other parts of importance does the penis present ? 
The meatus urinarius, the external orifice of urethra opening at 
summit of glans penis. 
The prepuce, a portion of skin of penis prolonged forward so as 
either completely or partially to cover glans penis, lined internally 
by a tissue resembling mucous membrane. 274 
ESSENTIALS OF HUMAN ANATOMY. 
The freenum preeputii, a fold of mucous membrane passing from 
behind meatus to bottom of a depressed raphe to become con- 
tinuous with under margin of prepuce. 
Glandulce Tysonii odoriferee, numerous small lenticular sebaceous 
glands upon corona and cervix of glans, secreting sebaceous matter 
with a peculiar odor. 
What is meant by erectile tissue ? 
An intricate venous plexus formed by the interspaces between 
the fibrous trabeculae, the blood being delivered in the following 
ways: (1) by arteries terminating in ordinary capillaries—this is 
the arrangement in the corpus spongiosum and glans—(2) fine 
convoluted arterial twigs opening directly into venous network by 
funnel-shaped extremities. 
What are the helicene arteries ? 
Convoluted, tendril-like arterial branches opening directly into 
venous plexus (supra), as just explained, most abundant in back 
parts of spongy and cavernous bodies. 
Name the arteries, veins, and lymphatics of the penis 
The arteries are all branches of internal pudic, viz., 
Artery of bulb, to corpus spongiosum. 
Arteries of cofpora cavernosa, to these bodies. 
Dorsal arteries of penis, to corpora cavernosa, glans, prepuce, and 
skin; the 
Veins return blood by dorsal vein, prostatic plexus, and pudental 
veins. 
Lymphatics, the superficial end in inguinal glands, the deep join 
deep pelvic lymphatics ; the 
Nerves are branches of internal pudic and hypogastric plexus 
of sympathetic. 
The Testes and their Coverings. 
What are the testes or testicles (Fig. 99) ? 
They are the procreating glands, those which secrete the seminal 
fluid, are of ovoid form compressed laterally, and are each ob- 
liquely suspended in the scrotum by their own spermatic cord. THE TESTES AND THEIR COVERINGS. 
275 
They measure from one and a half to two inches long, one inch in 
breadth, and one and a quarter inches antero-posteriorly, weighing 
from six to eight drachms, the left being slightly larger. 
What is the scrotum ? 
A cutaneous pouch containing the testicles and part of sper- 
matic cords, formed of integument externally and beneath this of 
a reddish contractile layer, the daftos, continuous with contiguous 
superficial fascia and sending inward a partition, the septum scroti, 
dividing the scrotum into two compartments. 
Describe the coats of the testis. 
They are, the 
Tunica vaginalis testis, a serous coat originally derived from peri- 
toneum, consisting of a portion investing the testis, the visceral 
layer, or tunica vaginalis propria, and a parietal layer, or tunica 
vaginalis refiexa; the 
Tunica albuginea is formed of white fibrous tissue surrounding 
the gland and reflected into its interior at its postero-superior 
border to form an incomplete vertical partition, the mediastinum 
testis, or corpus Highmorianum, from which fibrous septa pass, sepa- 
rating the glandular lobules; the 
Tunica vasculosa, or pia mater testis, consists of a plexus of blood- 
vessels bound together by areolar tissue, which invests the inner 
surface of the tunica albuginea and sends off processes between 
the lobules. 
What is meant by the coverings of the testis ? 
The structures with which the testes become invested in their 
passage, previous to birth, from the abdomen along the inguinal 
canals into the scrotum. 
Name these coverings. 
Skin, 
Dartos, 
scrotum, closely adhering to each other. 
Inter columnar, or external spermatic fascia, derived from margins 
of external abdominal ring. 
Cremaster muscle, derived from lower border of internal oblique 
muscle (some authors deny this). 276 
ESSENTIALS OF HUMAN ANATOMY. 
Infundibuliform, or fascia propria, a downward continuation of 
infundibuliform process of transversalis fascia. 
Tunica vaginalis, derived from peritoneum (supra). 
Describe the structure of the testis. 
It consists of some hundreds of seminiferous tubules, one-one- 
hundred and fiftieth to one-two-hundredths of an inch in diameter, 
convoluted so as to form three hundred conical lobules, with apices 
toward mediastinum ; the tubes then unite to form twenty or thirty 
larger ducts, one-one-fiftieth of an inch in diameter, called vasa 
rectac, which, passing upward and into the mediastinum, form a 
close network of anastomosing tubules, the rete testis; these, at the 
upper end of the mediastinum, terminate into twelve to twenty vasa 
efferentiae, perforate the tunica albuginea, and become enlarged 
and convoluted, forming coni vasculosif, which aggregated compose 
the globus major of epididymis; the tubules consist of a mem- 
bran a propria lined with a layer of polyhedral cells, with two or 
more inner layers of spheroidal cells, which divide into epithelial 
cells ultimately to become converted into spermatozoids; the vasa 
recta and tubes of rete testis have thin walls lined by one layer of 
squamous cells; the vasa efferentia and epididymis have thicker 
walls, containing muscular tissue and are lined with columnar 
epithelium. 
What is the epididymis ? 
A convoluted tube, some twenty feet long, lying along posterior 
border of testis, commencing on testicle side by convergence of tubes 
of coni vasculosi, and ending in the single vas deferens beyond. 
Describe its various parts. 
The globus major6 is formed by the coni vasculosi, or efferent 
ducts, which open at intervals into the single duct forming epi- 
didymis; the 
Bodys is the central portion formed by the convolutions of the 
tube bound together by delicate areolar tissue ; the 
Globus minor8 is the lower enlarged portion, composed as body 
is, and connected to testis by fibrous bands and areolar tissue ; the 
Vas aberrensi is a narrow tube extending up into cord for two 
or three inches, ending in a blind extremity, occasionally con- THE TESTES AND THEIR COVERINGS. 
277 
nected with lower part of tube of epididymis, or commencement 
of vas deferens ; the 
Hydatids of Morgagni are small bodies attached to epididymis or 
upper portion of testicle by pedicles ; one of these is probably the 
remains of the duct of Midler. 
Describe the vas deferensh. 
It is the excretory duct of testis, and a continuation of epididy- 
mis, commencing at globus minors to ascend along posterior side 
of testis and epididymis, back 
of spermatic cord, through the 
inguinal canal to internal ab- 
dominal ring, whence, passing 
into pelvis, it crosses external 
iliac, curves around epigastric 
artery to reach side, then by a 
curve downward and backward, 
the base of bladder internal to 
the ureter2 (Fig. 96); here it 
lies between the bladder and 
rectum, coursing along inner 
border of seminal vesicle5 (Fig. 
96) on each side, becoming en- 
larged and sacculated, but nar- 
rowing at base of prostate where, 
joined by duct of vesiculse semi- 
nales® (Fig. 96), it forms the 
ejaculatory duct7 (Fig. 96). It 
measures about two feet long, 
is about one and a quarter lines in diameter, its lumen measuring 
but one-third line, and has thick, rigid walls, presenting a hard, 
cord-like sensation when rubbed between the fingers. 
Fig. 99. 
What are the arteries of the testis and its coverings ? 
The gland itself is supplied by the spermatic arterym (Fig. 99), 
the coverings receive blood from superficial external pudic and deep 
externalpudic from femoral, superficial perineal from internal pudic, 
cremasteric from epigastric, and artery of vas deferens from superior 
vesical. 278 
ESSENTIALS OF HUMAN ANATOMY. 
The veins leave back of testicle forming the pampiniform plexus, 
which ends in a single trunk emptying on right side into ascend- 
ing vena cava, on left into left renal vein. 
Veins of the same name as arteries supplying coverings, return 
blood to femoral, external and internal iliac veins. 
What nerves go to each testicle and its coverings? 
Branches from spermatic plexus of sympathetic to testicle itself, 
to coverings and cord the ilio-inguinal, ilio-hypogastric, superficial 
perineal, inferior pudendal, and genital branch of genito-crural nerve. 
What are the component parts of the spermatic cord, and 
how are they disposed ? 
Vas deferens, 
Spermatic artery, 
Cremasteric artery, 
Artery of vas deferens, 
Spermatic veins, 
Spermatic nerve-plexus, 
Branch of ilio-inguinal nerve, 
Branch of genito-crural nerve, 
Vas aberrens (when present), 
Lymphatics. 
These form a cord bound together by connective tissue about four 
inches long, extending from globus minor to internal abdominal 
ring. 
Describe the vesiculae seminales. 
They are two lobulated membranous receptacles for the semen, 
which they dilute with their own secretion. They are pyramidal 
in form, are about two and a half inches long by five lines broad, 
by two to three lines thick, and lie in contact with base of bladder, 
diverging from each other from base of prostate to near entrance 
of ureters ; they join by their anterior pointed extremities with vas 
deferens, forming on each side the ejaculatory duds’1 (Fig. 96), 
terminating in prostatic urethra by slit-like orifices on each side of 
the sinusb (Fig. 97) at front of verumontanuin. 
Describe the descent of the testes. 
During early foetal life the testes lie at back part of abdomen, 
behind the peritoneum, just below and in front of kidneys; 
attaehed to lower end of epididymis, and attaining its full develop- 
ment from fifth to sixth foetal month is the gubemaculum testes, which 
contains muscular tissue; this divides below into three portions, FEMALE ORGANS OF GENERATION. 
279 
passing to Poupart’s ligament, to os pubis and rectus muscle, and 
to dartos at bottom of scrotum; the gubernaculum is supposed to 
contract and so cause descent of testicle, but this is a moot point. 
Between the fifth and sixth month each testis reaches the iliac 
fossa, by seventh it enters- internal abdominal ring, by eighth 
month it has reached the scrotum, carrying before it the peritoneal 
sac, the upper part of which usually becomes obliterated just 
before birth, the lower portion then forming the tunica vaginalis 
testis completely cut off from abdominal cavity; the other structures 
in front of the testis are likewise carried onward, forming its cover- 
ing, as already described (see page 275). 
Female Organs of Generation. 
What is the vulva ? 
The term includes the following organs : 
Labia minora13, 
Mons veneris4, 
Labia major a"', 
Vaginal orifice15, 
Clitoris6, 
Meatus urinarim1*, 
These parts are also called the pudendum and external organs of 
generation. 
Describe the mons veneris4. 
It is a rounded eminence surmounting vulva in front of pubes, 
formed by a collection of fatty tissue, and at puberty becomes 
covered with hair. 
Describe the labia majora5 and minora13. 
The Labia majora5 are two prominent longitudinal cutaneous 
folds passing downward from mons veneris to anterior part of 
perineum enclosing the common urinosexual opening. Each labium 
is formed externally of hair-covered skin, internally, of mucous 
membrane enclosing between these layers fatty areolar tissue and a 
structure resembling the dartos ; the junction of the labia in front 
constitutes the anterior commissure, that behind, the posterior com- 
missure; the 
Labia minora, or Nymphoe13, are two thin folds of mucous mem- 280 
ESSENTIALS OF HUMAN ANATOMY. 
brane, containing numerous sebaceous glands, inside the labia 
majora, running from clitoris6,—above which they form a hood-like 
prepuce,—obliquely downward for about one and a half inches on 
each side of vaginal orifice, to be lost in the labia majora. 
Describe the remaining structures forming the vulva. 
The clitoris6 is a small penis with root, body, and glans, composed 
of two corpora cavernosa formed of erectile tissue attached to rami 
of pubes and ischium by two crura7; it 
has a suspensory ligament and two erec- 
tores clitoridis muscles; the 
Vestibule is the triangular smooth sur- 
face below clitoris, bounded on each side 
by labia minora; the 
Meatus urinariusu is placed at back 
part of vestibule, about one inch below 
clitoris, near vaginal margin, surrounded 
by a prominence of mucous membrane; 
the 
Vaginal orifice15 is of an elliptical form, 
usually more or less closed in the virgin by 
hymen, and is. surrounded by sphincter 
vaginae muscle, the anologue of male 
accelerator urinse muscle; the 
Hymen is a thin fold of mucous membrane, variously shaped, but 
usually semilunar, with concavity upward, stretched across lower 
part of vaginal orifice ; it may occasionally form a complete occlud- 
ing membrane, the condition being then known as imperforate 
hymen; it may be practically absent in the virgin, and again, may 
persist after copulation, but at that time is usually ruptured, giving 
rise to small, rounded elevations surrounding vaginal outlet, called 
carunculce myrtiformes; the 
Glands of Bartholine16 are small, oblong, reddish-yellow bodies, 
lying on each side of commencement of vagina, each opening by 
a long single duct external to hymen on inner side of each labium 
majorum; the 
Bulbi vestibuli12 are two oblong masses—a venous plexus enclosed 
FiG- ]00- THE VAGINA. 
281 
in a fibrous envelope—extending from clitoris along each side of 
vestibule, a little behind labia majora; the 
Pars intermedia11 is another small venous plexus immediately in 
front of preceding, with which it is continuous as well as with 
glans clitoridis; the 
Fourchette is a small transverse mucous fold, just within posterior 
commissure; the 
Fossa navicularis is the space between fourchette and posterior 
commissure. 
Describe it. 
The Vagina. 
It is a cylindrical membranous canal flattened from before back- 
ward, lying between rectum and bladder, extending from vulva to 
uterus, curved forward and downward conforming to axis of pelvis 
and of outlet. Narrow at its orifice it is larger above, its an- 
terior wall measuring about four inches, its posterior six, being 
attached higher up on os uteri behind than in front. 
Describe its structure. 
It is formed of an external layer of erectile tissue, a muscular 
coat, and a lining mucous membrane with a median anterior 
and posterior raphe or columns of the vagina; it contains mucous 
glands; the epithelium is of the squamous variety. 
Give the relations of the vagina. 
Its anterior surface is in relation with base of bladder and 
urethra; 
The posterior surface is connected with lower three-fourths ot 
rectum, the upper fourth being separated from bowel by recto- 
uterine fold of peritoneum forming Douglas’s cul-de-sac or pouch-, 
Laterally, above it gives attachment to broad ligaments of uterus, 
below to levatores ani muscles and recto-vesical fascia. 
The Uterus and its Appendages. 
Describe the position and parts of uterus. 
It is the organ of gestation, situated in pelvic cavity between 
rectum and bladder, opening below into vagina, which is attached 282 
ESSENTIALS OF HUMAN ANATOMY. 
around its cervix. It is pear-shaped, flattened from before back- 
ward, is about three inches long, two inches in breadth at upper 
part, and one inch thick, weighing from one to one and a half 
ounces; it presents for examination the 
Fundus2, which is convex, covered with peritoneum, and placed 
below level of brim of pelvis; the 
Body1 gradually narrows from fundus to neck, with anterior 
flattened surface covered with peritoneum for its upper three- 
fourths, and a posterior peritoneum-covered convex surface, while 
each lateral margin is concave, affording attachment to Fallopian9 
tube above, to round ligament in front and below this, and to 
ovarian ligament below and behind both ; the 
Cervix3 is the lower, rounded, constricted portion of uterus pro- 
jecting into upper portion of vagina, which is attached further up 
behind than in front; the 
Cavity of the Body is small, triangular, flattened from before back- 
ward, its upper extended lateral angles forming funnel-shaped cavi- 
ties at the bottom of each of which opens, by a minute orifice, the 
Fallopian tube; at the inferior angle is the small opening into the 
cavity of the cervix called os internum or internal os uteri; the 
Fig. 101. 
Cavity of the cervix is spindle-shaped, flattened antero-pos- 
teriorly, and opens into cavity of uterus above by internal os uteri, 
and below into vagina by the external os uteri; a median longi- 
tudinal crest of mucous membrane on back and front walls from 
which proceed obliquely other smaller ones, forms the arbor vitce, 
hardly noticeable after the first labor; the 
Os externum or external os uteri (also os tinctse)4 is a transversely 
ovoidal opening from cervix into vagina which presents an anterior 
and posterior lip. THE UTERUS AND ITS APPENDAGES 
283 
Describe ligaments of uterus. 
Six are peritoneal folds, viz., 
Anterior or vesico-uterine, two crescentic folds passing between 
uterine neck and back of bladder; the 
Posterior or redo-uterine, passing between sides of uterus and 
rectum; the peritoneal pouch thus formed between rectum and 
uterus being called Douglas’s cul-de-sac or redo-vaginal pouch ; the 
Two lateral or broad ligaments7 (Fig. 101), stretched between sides 
of uterus and lateral walls of pelvis, dividing this cavity into two 
portions, and containing between their folds the Fallopian9 tubes 
and the round ligaments8. 
Describe the round ligaments of the uterus8. 
They are two rounded cords, four or five inches long, commenc- 
ing at superior angles of uterus to pass forward and outward 
through internal abdominal ring into inguinal canal to become 
lost, after dividing into three fasciculi, in the fatty tissue of mons 
veneris ; they consist of dense fibrous tissue and unstriped muscle, 
enclosed, in the foetal state, by a process of peritoneum extending a 
short distance into inguinal canal, the so-called canal of Nude, 
usually obliterated in adult, but sometimes pervious throughout 
life. 
Describe the structure of uterus. 
The womb has three coats, viz., a 
Serous, derived from peritoneum covering fundus of organ and 
its posterior surface, but only the superior three-fourths of its 
anterior surface ; a 
Muscular, forming bulk of uterus, composed of bundles of un- 
striped muscular tissue interspersed with areolar tissue, blood- 
vessels, lymphatics, and nerves. The fibres are disposed in three 
layers, viz., transverse, in front and behind fundus; middle layers, 
passing longitudinally, obliquely, and transversely; and circular, 
arranged in two hollow cones whose apices surround the orifices of 
the Fallopian tubes, whose bases fuse in middle of uterine body; 
at cervix these fibres pass transversely; a 
Mucous, thin, smooth, and closely adherent to subjacent parts, 284 
ESSENTIALS OF HUMAN ANATOMY. 
covered with columnar ciliated epithelium, and containing num- 
erous tubular follicles, most numerous in the cervix; when their 
ducts become obliterated their secretion is retained, forming small 
vesicular elevations within os and cervix uteri called Ovula of 
Naboth. 
Name the uterine vessels and nerves. 
The 
Arteries are the uterine, from internal iliac, and ovarian, from 
aorta, which pursue a very torturous course and freely anastomose. 
The veins accompany arteries and terminate in uterine plexuses; 
during pregnancy they are called uterine sinuses, consisting of the 
lining membrane of the vein adhering to the walls of canals chan- 
nelled through uterine substance ; the 
Lymphatics, terminate in pelvic and lumbar glands; the 
Nerves, are branches of inferior hypogastric, and spermatic 
plexuses, and of third and fourth sacral nerves. 
What are the Fallopian tubes ? 
They are the oviducts, two tubes about four inches long, ex- 
tending between layers of broad ligament on each side from supe- 
rior angle of uterus to sides of pelvis; the canal of each tube is 
very minute at its commencement the ostium internum at the 
superior angle of the uterine cavity, continuing so for inner half, 
when it gradually widens into the trumpet-shaped ostium abdomi- 
nale10, called from the fringe-like fimbrice10 which surround the 
opening—one of which is attached to ovary—the fimbriated ex- 
tremity10. Their walls are formed of a serous or peritoneal coat, a 
muscular, formed of longitudinal and circular fibres, and a mucous 
coat covered with ciliated columnar epithelium, continuous on 
one side with uterine lining, on other with peritoneum. 
Describe the ovaries11. 
They are two flattened, ovoid bodies suspended by their anterior 
margins from back of broad ligaments7, behind and below Fallo- 
pian tubes, upon either side of uterus; they are attached by their 
inner extremities to uterus by the ovarian ligaments and by their 
outer ends to one of fimbriae of Fallopian tube; their dimensions 
are, length, one and one-half inches; width, three-quarters of an 
inch ; thickness, one-third of an inch. THE UTERUS AND ITS APPENDAGES 
285 
Describe the structure of the ovaries. 
They consist of numerous Graafian vesicles imbedded in a fibrous 
stroma, covered externally by modified peritoneum, having col- 
umnar instead of squamous cells. 
The stroma consists of numerous spindle-cells with connective 
tissue and abundant bloodvessels; the condensed peripheral layer 
surrounding the organ was formerly described as the tunica albu- 
ginea. 
What are the Graafian vesicles ? 
Ovisacs, minute vesicles from one-one-hundredth of an inch in 
diameter, to even one-one-twentieth of an inch after puberty; 
microscopically, they are seen to consist of an external fibro-vascular 
coat connected with stroma by a vascular network, an internal coat, 
or ovicapsule lined by a layer of nucleated cells, the membrana 
granulosa, which are heaped up around ovum at that part of 
Graafian vesicle nearest the ovarian surface, forming the discus 
proligerus; it contains also a transparent, albuminous fluid, sus- 
pending the ovum in the immature vesicles. 
Describe the human ovum. 
It is a- spherical mass of protoplasm, one-one-hundred and 
twenty-fifth of an inch in diameter, and consists of the 
Vitelline membrane, or zona pellucida, a transparent sac surround- 
ing the 
Vitellus, or yelk, a fluid containing granules, among which is 
found the 
Germinal vesicle, containing a smaller body, the 
Germinal spot, one-thirty-six hundredths of an inch in diameter. 
What is the corpus luteum ? 
An irregular yellow spot in ovary at site of a ruptured Graafian 
vesicle, which differs in appearance according as it is a true or 
false corpus luteum. 
Describe the differences between these two kinds of corpora 
lutea. 
The true corpus luteum is that of pregnancy which increases up 
to a certain point, reaching sometimes the size of a mulberry, and 
usually does not entirely disappear until full term. 286 
ESSENTIALS OF HUMAN ANATOMY. 
Thq false corpus luteum is that following ordinary menstruation, 
is much smaller, and disappears in about three months. 
Name the ovarian arteries, veins, and nerves. 
The arteries are the ovarian, from aorta, anastomosing with 
uterine artery; these vessels also supply Fallopian tubes; the 
Veins follow arteries and form a plexus near ovary, called the 
Pampiniform plexus] the nerves are derived from inferior hypo- 
gastric or pelvic plexus, from ovarian plexus, and the Fallopian 
tubes receive branches from one of the uterine nerves. 
What is the parovarium ? 
It is also called the organ of Rosenmuller, is the remains of a 
foetal structure, and in the adult consists of a few closed epithelial- 
lined, convoluted tubes, one commonly ending in a bulbous 
hydatid-like swelling; at its uterine end the parovarium is con- 
nected with the remains of the Wolffian duct—the duct of Gaertner. 
The Mammary Glands. 
Describe the mammae. 
They exist in both sexes, being in male only rudimentary, but in 
female are two large hemispherical eminences situated toward 
lateral aspect of pectoral region on each side, reaching from axilla 
to sternum, and from third to sixth or seventh ribs; just below 
the centre projects a small, dark-colored conical prominence, the 
nipple, surrounded by a lighter colored areola, in which are 
numerous prominent sebaceous glands, which enlarge during 
pregnancy; the color of both nipple and areola darken during 
pregnancy, and the latter also extends its area. 
Describe the structure of the mammary glands. 
They are composed of gland-tissue, of fibrous tissue connecting 
the lobes, and fatty tissue in intervals between lobules ; the lobes 
consist of lobules formed of a number of rounded vesicles grouped 
about a small lactiferous tube into which their ducts open, which, 
by their union, finally form fifteen or twenty excretory ducts, or 
tubuli lactiferi, which converge toward the areolae, dilating beneath 
it into the ampullae at base of nipple, when they contract into THE SKItf AND ITS APPENDAGES. 
287 
straight tubes perforating the summit of the, nipple; the lobules 
are surrounded by a dense capillary network during lactation, as 
is also the nipple, which becomes erected when irritated, partly 
from fulness of blood, partly from contraction of its muscular 
tissue. 
Name the vessels and nerves of the mammae. 
The arteries are derived from thoracic branches of axillary, in- 
tercostal, and internal mammary arteries; the 
Veins form an anastomotic circle around the base of the nipple, 
called the circulus venosus, from which large vessels radiate to 
terminate in axillary and internal mammary veins; the 
Lymphatics chiefly run along lower border of pectoralis major to 
axillary glands, a few pass through intercostal spaces to anterior 
mediastinal glands; the nerves come from anterior and lateral 
thoracic cutaneous. 
THE ORGANS OF SENSE. 
The Skin and its Appendages 
Of what parts does the skin consist'? 
Epidermis, or cuticle, 
formed of 
superficial epithelial layers and the rete 
mucosum, or deep epithelial layerst 
which contain the pigment. 
Derma, cutis vera, or 
true skin, formed of 
papillary layer, upon which lies rete 
with an interposed basement mem- 
brane ; 
corium. 
Enumerate the accessory structures contained in the skin. 
The tactile corpuscles, in papillae of sensitive parts. 
Ducts of sweat-glands, 
Hair follicles, into which open 
sebaceous glands, 
passing through all the layers 
of the skin. 
Where do sweat- and sebaceous-glands with the hair 
follicles lie ? 
Chiefly in the subcutaneous fatty tissue, but sometimes in the 
deepest layers of the corium. 288 
ESSENTIALS OE HUMAN ANATOMY. 
Describe the epidermis. 
It is composed solely of epithelial cells, the deepest layer being 
columnar, more rounded in the middle portions, and flat, scaly, 
and horny on free surface; the deepest, softest layer is accurately 
moulded upon the papillary layer of the derma, and contains the 
skin pigment; it is called the rete mucosum. 
Describe the derma. 
Is a tough, flexible, and highly elastic tissue, protecting sub- 
jacent parts, and is the chief organ of the sense of touch ; excre- 
tion is effected by its various glands, and absorption also takes 
place from its surface. The derma consists of the 
Papillary layer, situated upon its free surface, presenting innu- 
merable, minute, vascular conical eminences, averaging in length 
one-one-hundredth of an inch by one-two-hundred and fiftieth of 
an inch in diameter at their bases, scattered irregularly in slightly 
sensitive parts, but arranged in parallel curved lines, forming ridges, 
in highly sensitive regions; each papilla contains one or more 
capillary loops, and one or more nerve fibres, some terminating in 
oval-shaped bodies, the 
Tactile corpuscles, where touch is most highly developed. 
The corium is composed of interlacing bands of white fibrous 
tissue, with some yellow elastic fibres, unstriped muscular fibres 
wherever hair exists, lymphatics, bloodvessels, and nerve-plexuses. 
What are the nails ? 
Flattened, horny structures of modified epithelium, covering the 
dorsal aspects of derma of distal phalanges of fingers and toes. 
They are convex externally, and have a root, imbedded in a groove 
of skin, whence the growth in length comes; a matrix, that por- 
tion of derma beneath, by which the nail grows in thickness; the 
lunula, the white crescentic portion next to root, its color owing to 
diminution in size, number, and vascularity of the papillse, which 
are disposed in longitudinal rows elsewhere in the matrix. 
What are the hairs ? 
They are also modified epidermis, found everywhere in skin, 
except palms of hands and soles of feet, but varying in size. They 
each have a ORGANS OF TASTE. 
289 
Root, bulbous in form, springing from a vascular papilla at the 
bottom of an involution of the epidermis and corium, called a 
hair-follicle, which sometimes extends into subcutaneous cellular 
tissue; into the hair-follicle open one or more sebaceous glands; 
the 
Shaft consists of a central or medullary portion, a fibrous portion, 
and a cortical of thin flattened scales; the medulla is commonly 
absent in fine hairs ; the 
Point is formed only of the fibrous and cortical portions. 
Describe the sebaceous glands. 
Most abundant in scalp, face, arm-pits, around nasal and oral 
apertures, and in external auditory canal; the largest are the Meibo- 
mian glands of eyelids; they are small sacculated glands, lodged 
in the corium or subcutaneous tissue of nearly every part, except 
palmar and plantar surfaces; the ducts usually open into hair 
follicles, but sometimes on general surface of skin. 
Describe the sweat glands. 
They are each formed of a single convoluted tube, situated either 
in deepest portion of corium, or more usually in subcutaneous 
cellular tissue, and opening on free surface by a spiral duct; the 
tubes are formed of an external fibro-cellular coat, continuous 
with superficial layer of corium, and a lining of epithelial cells 
continuous with epidermis. 
What is their estimated number and area ? 
Nearly two and a half millions, forming an evaporating area of 
about eight square inches. 
Organs of Taste. 
Where does the sense of taste reside ? 
In the mucous membrane of dorsum of tongue, upper portion of 
pharynx, soft palate, and fauces. 
Are there any special taste-organs ? 
Yes, the taste-goblets, flask-like bodies with their bases resting on 
corium, and a neck opening between epithelial cells. They consist 290 
ESSENTIALS OF HUMAN ANATOMY. 
of spindle-shaped, flattened cells externally, with central spindle- 
cells, whose inner fine terminations are continuous with a terminal 
nerve fibril; these bodies are found in the circumvallate and some 
of the fungiform papillae, and at the side of base of tongue. 
What are the special nerves of taste ? 
For its anterior two-thirds, chorda tympani of facial, recognizing 
acid, saline, and styptic qualities (according to Flint). 
For posterior third, lingual branch of the glossopharyngeal, for 
perception of alkaline, metallic, sweet, and bitter tastes (Flint). 
Organs of Smell. 
Where does the sense of smell reside? 
In the mucous membrane lining upper portion of nasal fossae, 
where the olfactory nerve filaments are distributed. 
Describe the nasal mucous membrane. 
It is also called the Schneiderian, or pituitary membrane, and is 
continuous with that of pharynx, Eustachian tube, tympanum, 
Fig. 102. ORGAN’S OF SMELL. 
291 
and mastoid cells, and with that of the accessory nasal cavities, the 
frontal, ethmoidal, and sphenoidal sinuses and antrum, also through 
lachrymo-nasal duct, with conjunctiva. Its epithelium is ciliated 
columnar below, and simple columnar above; it contains numerous 
mucous glands, and in the deeper portions of epithelial layer certain 
nucleated bodies are found, the olfactory cells of Schultze with 
two processes, one running between epithelial cells to free surface, 
the other inward, to connect with a terminal nerve fibre. 
What vessels supply the exterior of the nose ? 
Lateralis nasi, from facial to alse of nose; the 
Artery of septum, from superior coronary to septum ; the 
Nasal branches of ophthalmic and infraorbital to dorsum and 
sides of nose; the veins terminate.in the facial and ophthalmic. 
What are the vessels of the nasal fossae ? 
Anterior and posterior ethmoidal from ophthalmic to ethmoidal 
cells, frontal sinuses, and roof; the 
Spheno-palatine and twig from small meningeal, from internal maxil- 
lary to membrane over spongy bones, meatuses, and septum ; the 
Alveolar, from internal maxillary to antrum ; the 
Veins usually accompany the arteries, terminating in facial, 
ophthalmic, and other trunks. 
What are the nerves of the nose ? 
Branches of facial, inf raorbital, infratrochlear, and nasal branch 
of ophthalmic. 
Describe the nerve-supply to the nasal fossae. 
The olfactory1 is distributed to mucous membrane over upper 
third of septum, and superior and middle spongy hones ; the 
Nasal branch of ophthalmic1 supplies upper anterior part of sep- 
tum and outer wall; the 
Anterior dental branch of superior maxillary supplies inferior turbi- 
nated bone and inferior meatus ; the 
Spheno-palatine6, by naso-palatine branch7, supplies middle of 
septum, by anterior palatine, the middle and inferior spongy bones. 
The Vidian10 supplies the upper back part of septum and superior 
spongy bones, parts to which are also distributed the upper ante- 
rior nasal branches of spheno-palatine ganglion7. 
(For bones forming nasal fossae, see p. 58.) 292 
ESSENTIALS OF HUMAN ANATOMY. 
The Eye. 
It is a spherical organ, with the segment of a smaller transparent 
sphere, the cornea, forming its anterior portion, lying in the orbit 
in a cushion of fat, and held in position by the ocular muscles, the 
optic nerve, conjunctiva, and eyelids. The following points should 
be studied, the 
Diameters, antero-posterior in adult about ninety-five hun- 
dredths of an inch, transverse ninety-two hundredths of an inch, 
vertical ninety hundredths of an inch. 
Anterior and posterior poles, the centres respectively of the cornea 
and fundus oculi. 
Axes of eyeballs, or ocular axes which pass through the poles of 
each eye and are nearly parallel, not corresponding to axes of orbits, 
which diverge. 
Visual axis passes from the yellow spot through the centre of 
curvature of the refracting media, so that these axes converge. 
Nodal point, the centre of curvature of refracting media. 
Equatorial plane, that passing through centre of eyeball at right 
angles to the axis, dividing the globe into two segments, an ante- 
rior and a posterior hemisphere. 
Equator, the line where the just-mentioned plane cuts the surface 
of eyeball. 
Meridional planes, planes coinciding with ocular axis. 
Meridians, the lines where meridional planes cut surface of eye- 
ball. 
Describe the eyeball. 
What is the capsule of Tenon ? 
The tunica vaginalis oculi, and consists of a thin membranous sac 
isolating the eyeball and allowing free movement, arising from 
optic foramen behind to become lost upon sclerotic in front, having 
a visceral layer investing posterior portion of globe, and a parietal 
layer lining the fatty cushion in which eye rests, both layers being 
lined by flattened endothelial cells: the lymphatic vessels of the 
sclerotic open into it, the cavity being a lymph space also com- 
municating with the lymph-spaccs of the optic nerve sheath; the SCLEROTIC AND CORNEA. 
293 
ocular muscles pierce this capsule: that portion of the capsule be- 
hind the point of passage of the tendons is sometimes called the 
Capsule of Bonnet, while to that in front the name of 
Capsule of Tenon has been restricted; this is an unnecessary 
refinement. 
What are the tunics or coats of the eye ? 
The sclerotic? acid cornea?, the most external, protective tunic. 
Choroid, iris, and ciliary processes, the middle or vascular tunic. 
Retina, the innermost, nervous tunic. 
What are the humors of the eye ? 
The refracting media, three in number, viz., the 
Aqueous3, filling anterior chamber. 
Crystalline4,, or crystalline lens. 
Vitreous5, filling posterior four-fifths of the globe. 
Sclerotic and Cornea. 
Describe the sclerotic. 
It is a firm, unyielding fibrous membrane maintaining the form of 
the posterior five-sixths of the globe, thicker behind than in front, 
with smooth white external surface except where tendons are 
attached, covered in front by conjunctival membrane, and having 
an inner brown-stained surface grooved for ciliary nerves. Pos- 
teriorly to the nasal side it is pierced by the optic nerve with whose 
sheath it is continuous, the sclerotic at this point forming a thin 
Lamina cribrosa through whose openings the nerve filaments 
pass, the most central orifice, called the porus opticus, transmitting 
the arteria centralis retinae. Surrounding the cribriform lamella 
are numerous small openings for the ciliary vessels and nerves; 
the venae vorticosae emerge midway between margin of cornea and 
entrance of optic nerve, and the anterior ciliary vessels around the 
corneal border. The sclerotic is formed of white fibrous tissue, 
mingled with fine elastic fibres and fusiform nucleated cells. The 
following points should be noted ; the 
Thickness, about one-twenty-fifth of an inch posteriorly, one-six- 
tieth of an inch anteriorly ; 294 
ESSENTIALS OF HUMAN ANATOMY. 
Lamina jusca, the fine cellular tissue connecting sclerotic with 
choroid; the 
Subconjunctival tissue, loose areolar tissue binding conjunctiva to 
sclerotic; the 
Arteries are few, come from ciliary, and form a coarse network; the 
Anterior vascular zone, surrounding cornea, formed by subcon- 
junctival branches of anterior ciliary vessels; the 
Nerves, whose existence is very doubtful. 
Describe the cornea. 
It is the transparent, projecting, anterior sixth of the external 
tunic. It is not quite circular, being a little broader in the trans- 
verse than the vertical diameter, and is set in sclerotic somewhat 
Fig. 103- 
like a watch-crystal in its case: its thickness, one twenty-second of 
an inch to one thirty-second of an inch, is nearly same throughout 
except toward outer margin where it is thinner: it is non-vascular, 
the capillary vessels forming loops at its circumference: the nerves 
are numerous, estimated at from twenty-four to forty-five, and are 
derived from the ciliary nerves. 
Section of eyeball. SCLEROTIC AND CORNEA. 
295 
Describe the structure of the cornea. 
It consists from without inward, of the following layers: 
Layer of conjunctival epithelium, the deepest columnar, next poly- 
hedral, most superficial three or four layers of scaly cells; the 
Anterior elastic lamina or membrane of Bowman, one two-thousandth 
to one-twelve-hundredths of an inch thick, forming a thin, firm, 
elastic layer consisting of extremely closely interwoven fibrils 
similar to those of corneal tissue proper, but with no corneal cor- 
puscles; the 
True corneal tissue is fibrous, tough, unyielding, continuous with 
sclerotic and composed of sixty, superimposed, flattened lamellae 
made up of fibrillar connective-tissue continuous with fibres of 
sclerotic: the layers are held together by a cement substance in 
which are corneal spaces, stellate in form, communicating with ad- 
jacent spaces by processes, each space containing a similarly shaped 
but smaller corneal corpuscle which does not entirely fill it; the 
Posterior elastic lamina (membrane of Descemet or Demours) is 
a structureless, elastic, brittle, extremely thin membrane, not ren- 
dered opaque by water, alcohol, or acids: it chief peculiarity is the 
tendency to roll upon itself with the attached surface innermost, 
when separated from cornea proper: at its circumference it breaks 
up into bundles of fibres joining the ligamentum pedinatum iridis; 
the 
Posterior epithelial layer is a single layer of polygonal transparent 
nucleated cells. 
Describe the choroid. 
It is a thin, dark-brown, vascular membrane investing the pos- 
terior five-sixths of globe terminating in front at ciliary ligament, 
there bending inward to form the ciliary processes: it is connected 
externally with sclerotic by the lamina fusca, and consists of two 
layers, the 
External layer is formed of the larger branches of the ciliary arte- 
ries and the venae vorticossef, interspersed with stellate pigment 
cells by the union of whose processes a delicate network is formed; 
externally the choroid is covered by a layer of elastic fibres, the 
membrana suprachoroidea, coated externally with endothelial cells; 
the 296 
ESSENTIALS OF HUMAN ANATOMY. 
Internal layer or membrana Ruyschiana consists of a fine capillary 
plexus formed by the short ciliary vessels, which is separated from 
pigmentary layers of retina by the 
Vitreous membrane, a thin, structureless layer. 
The arteries of the choroid are the short, posterior ciliary, and 
recurrent branches from the long posterior and anterior ciliary; 
the 
Veins, form four to five venae vorticoscef (Fig. 104), which pierce 
the sclerotic midway between corneal margin and optic nerve; the 
Nerves are the long and short ciliary nerves. 
What are the ciliary processes ? 
Sixty to eighty folds formed by plaiting and folding inward of 
choroid at its anterior margin, which are received between corre- 
sponding folds of the suspensory ligament of the lens; they con- 
sist of large and small processes, irregularly alternating, the former 
about one-tenth of an inch long. 
What is the ciliary body ? 
It is that portion of the middle tunic between the choroid and 
iris formed of the ciliary muscle and ciliary processes. 
Describe the ciliary muscleb. 
A grayish circular band of unstriped muscular fibre about one- 
eighth of an inch broad, thickest in front, thinnest behind, con- 
sisting of radiating and circular fibres, the former, the more 
numerous, arising from junction of cornea and sclerotic to pass 
backward to choroid opposite the ciliary processes; the latter are 
internal, and pursue a circular course around the insertion of the 
iris; they are called the “ ring-muscle” of Muller and were for- 
merly described as the ciliary ligament. 
Describe the circulus arteriosus major and minor. 
The former is an anastomotic ring formed by long ciliary arte- 
ries in the ciliary muscle; the latter, a second anastomotic circle 
formed by transverse offsets from the converging branches passing 
forward from the circulus major. 
Describe the irisc (Fig. 104). 
It is a thin, circular, perforated contractile curtain, suspended 
behind the cornea in the aqueous humor in front of the crystalline SCLEROTIC AND CORNEA. 
297 
lens, forming the anterior portion of the middle ocular tunic, and 
is formed of radiating and circular muscular fibres, and of a fibrous 
stroma. Anteriorly it is covered by a layer of polyhedral cells 
resting on a fine basement membrane, being continuous with the 
membrane of Descemet. It presents for examination the 
Pupil, the nearly central opening in iris placed a little to nasal 
side of centre; the 
Ligamentum peetinatum iridis, a reticular tissue, connecting iris 
with cornea, derived from membrane of Descemet which sends 
fibrous prolongations to iris and sclero-corneal junction ; the 
Fig. 104. 
Spaces of Fontana, the intervals between the reticulated fibres of 
the ligamentum peetinatum at outer angle of anterior chamber, 
which communicate with a larger space in the sclerotic close to 
sclero-corneal junction; the 
Canal of Schlemm or Sinus circularis iriclis, lined with endothe- 
lium, a venous sinus, containing two or three plexiform veins re- 
ceiving blood from the sclerotic and ciliary plexuses and com- 
municating with anterior ciliary veins; the 
Uvea, a layer of purplish-hued pigment-cells on posterior surface 
of iris continuous with pigment layer of ciliary processes ; the 
Sphincter pupillce, the narrow band of circular muscular fibres 
surrounding pupil on its posterior surface, about one-thirtieth of 298 
ESSENTIALS OF HUMAN ANATOMY. 
an inch wide, supplied by third nerve through ophthalmic gang- 
lion; the 
Dilator pupillce, consisting of the radiating muscular fibres con- 
verging from circumference of iris toward pupillary margin, where 
they blend with the circular fibres; it is supplied by sympathetic 
fibres from ophthalmic ganglion ; the 
Membrana pupillaris, a-delicate, transparent, vascular membrane 
which occluded the pupil in the foetus, usually disappearing about 
eighth foetal month, but occasionally persisting; it is nourished 
by many small vessels continued from margin of iris to those on 
front part of lens capsule; the 
Arteries, are branches of long and anterior ciliary forming the 
circulis iridis major and minor (see p. 298); the 
Veins, empty into those of ciliary processes and anterior ciliary 
veins; the 
Nerves, are branches of third, fifth, and sympathetic, through 
long and short ciliary nerves, the third going to sphincter pupillae 
(circular fibres), the sympathetic to dilator pupillae (radiating 
fibres), and the fifth supplying common sensation. 
What is the retina ? 
The innermost ocular tunic, forming a delicate, grayish, trans- 
parent nervous membrane, thicker behind than in front, terminat- 
ing nearly as far forward as the ciliary body by a ragged margin, 
the ora serrata, hut its fibrous stroma covered by the pigment layer 
passes forward to iris as thenars ciliaris retince. It presents the 
Macula lutea or yellow spot of Sommering, a round elevated 
spot exactly in centre of retina posteriorly, which corresponds to 
axis of eye; here vision is most perfect, the retina being thin, 
crowded with nerve elements, but destitute of rods and the nerve- 
fibre layer; the 
Fovea centralis is a minute central depression at summit of yellow 
spot; the 
Optic 'papilla or disk is the point of entrance of optic nerve, cen- 
trally pierced by arteria centralis retinae, lying about one-tenth of 
an inch to inner side of yellow spot; it is the only portion of retina 
where the sense of vision is wanting, and is therefore called the 
blind spot; the SCLEROTIC AND CORNEA. 
299 
Pars ciliaris retince consists of the fibrous and pigmented portions 
of retina, destitute of nerve elements, continued over ciliary pro- 
cesses to iris; the 
Arteries of retina spring from arteria centralis retinae, a branch of 
the ophthalmic, which after piercing the optic nerve divides into 
four or five branches which soon 
enter the nervous layer of retina 
to form a fine capillary plexus not 
extending beyond inner nuclear 
layer; no vessels exist in the fovea 
centralis and very few in the mac- 
ula lutea. 
Describe the structure of the 
retina. 
It is exceedingly complex, being 
composed from within outward of 
the following ten layers, 
1. Membrana limitans interna, a 
transparent membrane formed of 
retinal connective tissue, lying in 
contact with hyaloid membrane of 
vitreous humor. 
2. Fibrous layer, composed of 
continuations of optic nerve fibres 
deprived of their medullary sheaths, 
forming radiating bundles or plex- 
uses. 
3. Vesicular layer, a single layer 
of large ganglion cells, except at 
macula lutea where there are several layers; they have one pro- 
cess prolonged into the fibrous layer becoming continuous with a 
nerve fibril, and one or more extending into inner molecular layer 
or, according to some, passing through it to terminate in inner 
nuclear layer. 
4. Inner molecular layer, made up of a dense reticulum of minute 
fibrils, mingled with processes of ganglion cells and those of next 
layer, containing in the interstices minute clear granules. 
Fig. 105. 300 
ESSENTIALS OF HUMAN ANATOMY 
5. Inner nuclear layer, containing (1) oval nuclei with two pro- 
cesses, one passing inward to inner molecular layer, believed to 
become continuous with processes of ganglion cells, and another 
passing into outer molecular layer, these bifurcating and (accord- 
ing to some) communicating with rod and cone fibres; (2) nucleated 
cells without branches ; (3) cells connected with fibres of Muller. 
6. Outer molecular layer, is thinner, resembles the inner molecular 
layer, but contains branched stellate cells—probably ganglion 
cells. 
7. Outer nuclear layer, consists of (1) rod-granules, transversely 
striated cells, with an external fine process connected with a single 
rod of Jacobs’s membrane, and an internal prolongation which 
enlarges, then breaks up into minute fibrils entering the outer 
molecular layer; and (2) cone-granules, closely connected with 
cones of Jacobs’s membrane, with a thick process passing inward, 
lecoming bulbous and terminating by numerous fibrillse, which 
enter outer molecular layer. 
8. External limiting membrane, a membrane formed of retinal 
connective tissue, perforated by numerous openings. 
9. Jacobs’s membrane or rods and cones, composed of rods arranged 
perpendicularly to surface, each composed of an outer and inner 
portion joined by cement substance; and cones, with apices directed 
toward choroid, formed of two portions and like rods their outer 
segments are transversely striated; this is probably the perceptive 
layer of retina. 
10. Pigmentary layer, formerly considered part of choroid, con- 
sisting of a single layer of hexagonal, pigmented epithelial cells. 
The connective tissue is modified to form a fenestrated, sponge- 
like structure the membrane of Muller. 
The Humors. 
What is the aqueous humor ? 
A small amount of clear alkaline fluid composed of water 96.7, 
albumen 0.1, sodium chloride and extractive 3.2, filling anterior 
and posterior chambers of the eye. THE HUMORS. 
301 
What are the anterior and posterior chambers of the eye ? 
The anterior chamber is a space filled with aqueous humor 
bounded in front by cornea, behind by front of iris, and communi- 
cating through pupil with the 
Posterior chamber, also filled with aqueous humor, which is now 
thought to be only a narrow chink between peripheral portion of 
iris, the suspensory ligament, and ciliary processes. 
Describe the vitreous humor. 
This forms about four-fifths of entire globe, is transparent, of the 
consistence of thin jelly, and is composed of an albuminous saline 
fluid enclosed, except where hollowed out for crystalline lens, in a 
delicate hyoloid membrane, beneath which are small, granular, 
nucleated cells; it possesses neither vessels nor nerves, and is 
hollowed out in front where the crystalline lens reposes. Running 
from entrance of optic nerve to posterior surface of crystalline 
lens is the canal of Stilling or hyaloid canal, filled with fluid and 
lined with a process of the hyaloid membrane. 
Describe the crystalline lens with its ligaments, etc. 
It is a traijsparent double convex body, more convex posteriorly 
than in front, enclosed in a capsule, and is lodged in a depression 
of the vitreous humor, where it is retained by its suspensory liga- 
ment. It lies immediately behind the pupil surrounded and 
slightly overlapped by the ciliary processes, measuring about one- 
third of an inch transversely by one-fourth of an inch antero- 
posteriorly, and is composed of water 60, soluble albuminous 
matter 35, insoluble albuminous matter 2.5, fat and cholesterine 2 
per cent.; its 
Capsule, is transparent, very elastic, and brittle, measuring one- 
two thousandth of inch in front, one-six thousandth of an inch be- 
hind, and is attached anteriorly to lens by a single layer of 
polygonal nucleated cells, which absorb fluid post-mortem, and 
breaking down from the liquor Morgagni; the 
Suspensory ligament or zonula of Zinn, is a thin transparent 
membrane, containing longitudinal elastic fibres, connecting an- 
terior margin of vitreous with anterior surface of lens near its cir- 302 
ESSENTIALS OF HUMAN ANATOMY. 
cumference, presenting upon its outer surface a number of folds 
between which fit the similar projections of the ciliary processes ; 
the 
Canal of Petit is about one-tenth of an inch wide, passing around 
circumference of lens, bounded in front by suspensory ligament, 
behind by vitreous humor, its base being formed by capsule of 
lens; when inflated it becomes sacculated. 
What is the structure of the crystalline lens ? 
It is formed of numerous laminae, composed of hexagonal fibres 
one-five thousandth of an inch broad, with serrated margins, those 
of contiguous fibres accurately fitting one another; the lens is also 
divisible after boiling or immersion in alcohol into three triangular 
segments with their bases outward. The central harder portion is 
called the nucleus, the peripheral portions the cortex; it possesses 
neither vessels nor nerves. 
Describe the muscles of the eyeball. 
Rectus superior4: origin, upper margin of optic foramen and 
sheath of the optic nerve; insertion, sclerotic coat three to four lines 
from cornea; action, turns eyeball upward; nerve, third cranial. 
Rectus inferior: origin, ligament of Zinn; insertion, sclerotic 
three to four lines from cornea; action, turns eye downward; 
nerve, third cranial. 
Rectus internus: origin, ligament of Zinn; insertion, sclerotic 
three to four lines from cornea; action, turns eye inward; nerve, 
third cranial. 
Rectus externus6: origin, by two heads, the upper8 from the outer 
margin of optic foramen, the lower7 from ligament of Zinn, and a 
pointed bony process at the lower margin of the sphenoidal fissure; 
insertion, sclerotic, as other recti; action, turns eye outward; nerve, 
sixth cranial (abducens): between the two heads pass the oph- 
thalmic vein, the third, nasal branch of the fifth, and the sixth 
cranial nerves. 
Obtiquus superior2: origin, one line above the inner margin of 
the optic foramen, terminating in a rounded tendon which plays 
through a fibro-cartilaginous ring or pulley3 beneath the internal 
angular process of the frontal bone, whence it passes beneath the 
superior rectus; insertion, sclerotic between superior and external THE HUMORS. 
303 
recti, midway between the cornea and entrance of the optic nerve; 
action, rotates eye on its antero-posterior axis; nerve, fourth cranial 
(patheticus). 
Obliquus inferior10: origin, orbital plate of superior maxillary; 
insertion, sclerotic between superior and external recti; action, 
rotates eyeball on antero-posterior axis; nerve, third cranial. 
(For muscles of pp. 116, 117.) 
Fig. 106. 
Recapitulate the nerve supply of the ocular muscles 
Third cranial, or motor oculi, supplies superior, internal and in- 
ferior recti, and inferior oblique muscles. 
Fourth cranial or patheticus, supplies superior oblique muscle. 
Sixth cranial or abducent, supplies external rectus muscle. 
Describe the vascular supply of the eyeball and its append- 
ages. 
(All branches of the vessels not supplying these parts will be 
omitted, having been already described on page 161.) 
Ophthalmic, arising from cavernous portion of internal carotid, 
entering orbit by optic foramen, giving off the 304 
ESSENTIALS OF HUMAN ANATOMY 
Lachrymal to lachrymal gland, conjunctiva, and upper eyelid, 
inosculating with palpebral arteries. 
Supra-orbital, supplies levator palpebrse and superior rectus 
muscles. 
Superior and inferior palpebral, supply eyelids. 
Nasal, supplies lachrymal sac. 
Short ciliary, twelve to fifteen in number, penetrate sclerotic 
around optic nerve entrance to supply choroid and ciliary processes. 
Long ciliary, two in number, penetrate sclerotic, pass forward 
between it and choroid to supply iris, forming circulus iridis major 
near ciliary margin, and circulus iridis minor, near margin of pupil. 
Anterior ciliary, spring from muscular branches, perforate scle- 
rotic, and join circulus iridis major. 
Arteria centralis retinae, obliquely traverses optic nerve to be 
distributed to retina. 
Muscular branches, one superior, one inferior, to ocular muscles. 
Anterior cerebral, from internal carotid, gives twigs to optic 
nerve. 
Infra-orbital, from internal maxillary, supplies inferior rectus 
and inferior oblique muscles and lachrymal gland. 
What are the chief lymph-spaces of the eyeball? 
The perichoroidal space, between choroid and sclerotic. 
Cavity of capsule of Tenon, between eyeball and capsule. 
Vaginal space, between optic nerve and sheath. 
What veins return the blood from the eye ? 
The superior and inferior ophthalmic emptying into the cavernous 
sinus; they also freely anastomose with the facial veins. 
Name the nerves of the eye. 
Optic or second cranial, nerve of special sense: motor nerves, the 
third, fourth, sixth, and sympathetic filaments. 
The Ophthalmic division of fifth, supplies general sensation by 
Lachrymal, to same-named gland, conjunctiva, and skin of upper 
eyelid; also the following branches : 
Supra-trochlear _ and Nagal 
Infra-orbital 
Ganglionic. 
Long ciliary. 
. Injra-trochlear. 
Frontal THE HUMORS. 
305 
The sympathetic arises from cavernous and carotid plexus re- 
ceiving communicating filaments indirectly from spinal nerves, 
and sending branches to third, fourth, fifth, and sixth nerves; the 
dilator fibres (radiating) of iris, ciliary ganglion, muscles of orbit 
and lids, with walls of arteries, receive their sympathetic nerve 
supply from this source; the 
Short ciliary, numbering about ten, arise from ciliary (ophthal- 
mic) ganglion, and pierce the sclerotic posteriorly, to ramify in 
sheath of optic nerve, choroid, ciliary muscle, iris, and cornea; 
the 
Ascending branches of the spheno-palatine (Mechel's) ganglion, 
reaching orbit by spheno-maxillary fissure, usually considered to 
supply only periosteum, are believed by some to go to optic and 
sixth nerves and ciliary ganglion. 
Give a brief description of optic tracts. 
The deep origin of the nerve fibres of these tracts are the optic 
thalami, corpora genieulata, and nates of corpora quadrigemina, 
which, forming two flattened bands, wind around crus cerebri, to 
which they are slightly attached, as well as to lamina cinerea and 
tuber cinereum, and joining in front of latter they form the optic 
commissure (see page 200 for illustration and more elaborate descrip- 
tion). 
What course do the nerve fibres pursue in the optic com- 
missure or chiasm? 
The most numerous, the decussating fibres, connect the right 
hemisphere with the left retina, and the left hemisphere with the 
right retina, occupying the centre of the commissure. 
Other fibres (longitudinal, cerebro-retinal) connect each hemi- 
sphere with the retina of its own side. 
Others (inter-cerebral) pass posteriorly, connecting the two optic 
tracts. 
Others (inter-retinal) pass anteriorly, connecting the two retinae. 
What are the origin and course of the optic nerves ? 
They arise on either side from the optic commissure, each passes 
into the orbit through optic foramen with central artery of retina, 
which pierces it, and enter eyeball through lamina cribrosa one- 306 
ESSENTIALS OF HUMAN ANATOMY. 
tenth inch to nasal side of globe, to aid in forming retina; these 
nerves are surrounded with a sheath derived from the dura mater 
between which and nerve is a lymph space communicating with 
subarachnoid space. 
APPENDAGES OF EYE. 
(Tutamina Oculi.) 
Name these. 
Eyebrows, or supercilia, 
Eyelids, or palpebrce, 
Conjunctivaa, a mucous 
membrane, 
Lachnjmal gland1 and ducts1, 
■ Lachrymal sac, 
Lachrymo-nasal duct. 
What are the eyebrows ? 
The arched eminences of skin surmounting upper margins of 
orbits on each side, from which grow several rows of short, ob- 
liquely placed hairs; by the attached muscles the eyebrows can 
partially shut off light from eyes. 
What are the eyelids ? 
Two movable curtains protecting by their closure the eyes from 
injury; the upper lid is the larger and more movable, having its 
own elevator muscle; the 
Palpebral fissure is the elliptical space between the margins of 
lids when opened, the internal and external angles being called, 
respectively, the internal and external canthus, the former being 
prolonged inward, leaving a triangular space between the lids, the 
lacus lachrymalis, at the commencement of which is a small eleva- 
tion on each lid, the lachrymal papilla3, whose summit is pierced 
by a minute opening, the punctum lachrymale3, the commencement 
of the lachrymal canal. 
What structures form the eyelids ? 
Externally the skin, beneath which is much loose areolar tissue, 
separating it from the fibres of the orbicularis palpebrarum muscle. 
The lids retain their shape by means of the so-called tarsal carti- APPENDAGES OF EYE. 
307 
lages—in reality dense connective tissue without cartilage cells— 
that for the upper lid being semilunar and the larger, that for lower 
lid elliptical; these structures are connected at their orbital mar- 
gins with the circumference of the orbit by a fibrous membrane, 
the tarsal ligaments, while in addition a rounded fibrous cord, 
the tendo-oculi, passes between the inner angle of each and the 
nasal process of superior maxillary hone. 
Imbedded in the cartilages are numerous sebaceous glands, the 
Meibomian glands, discharging their secretion upon the free edge 
of lids, preventing their adhesion ; they number thirty or forty in 
the upper lid, fewer in the lower lid. 
Attached to the free margins of lids is a double or triple row of stiff 
hairs, curved in each lid so that their convexities meet, preventing 
interlacing, these are the cilia, or eyelashes-, the inner surfaces of 
lids are lined by a mucous membrane, the conjunctiva. 
Their vascular supply is from the palpebral branches of ophthalmic 
artery anastomosing with contiguous branches of facial. 
The nerves are the third, seventh, and sympathetic to muscles, 
the ophthalmic branch of fifth to skin and conjunctiva. 
Describe the conjunctiva. 
It is a mucous membrane lining the inner surfaces of the eyelids 
and reflected thence upon anterior segment of sclerotic, its epithe- 
lial layer passing over cornea; the 
Palpebral conjunctiva is thick, opaque, vascular, and covered 
with papillae, containing numerous glands; at the inner angle of 
the eye it forms a semilunar fold, the plica semilunaris4 (Fig. 108). 
The folds formed by the passage of the conjunctiva from lids to eye- 
ball are called the superior and inferior palpebral folds, the former 
being the deeper; they contain numerous convoluted mucous 
glands; the 
Ocular conjunctiva is thin, transparent, possesses few vessels in 
health, and is loosely attached to globe by the subconjunctival 
areolar tissue. 
What is the caruncula lachrymalis5 (Fig. 108) ? 
It is a small, conical, reddish body, at inner canthus, occupying 
the space called the lacus lachrymalis, and is formed of a group of 
follicles, resembling the Meibomian glands, covered with con- 
junctiva; from the caruncle project a few slender hairs. 808 
ESSENTIALS OF HUMAN ANATOMY. 
Describe the lachrymal apparatus. 
It consists of the lachrymal gland with its ducts, the canaliculi, 
the lachrymal sac, and the nasal duct. The 
Lachrymal gland1 (Fig. 107) is an oval, compound racemose 
gland of the size and shape of an almond, lodged in a depression 
at upper, outer portion of orbit, its concave under surface resting 
upon the globe of eye, the conjunctiva, superior and external recti 
muscles intervening; it is held in contact with orbital periosteum 
by a few fibrous bands. It has six or seven 
Fig. 107. 
Fig. 108. 
Ducts2 (Fig. 107), opening by minute orifices on upper outer 
half of palpebral conjunctiva near superior retro-tarsal fold. The 
secretion, or the 
Tears, are taken up by the puncta, thence passing through canal- 
iculi into lachrymal sac and nasal duct, thus reaching inferior 
meatus of nose. 
Describe the canaliculi. 
They are two minute canals1 about one-half a line in diameter, 
commencing at the puncta, the superior passing upward, then 
bending acutely to pass inward to lachrymal sac, the inferior 
passing downward, then upward and inward ; they are lined with 
mucous membrane continuous with conjunctiva, and are one-third 
of an inch long. THE EAR. 
309 
What is the lachrymal sac2 (Fig. 108) ? 
It is the flattened, ovoidal, sacciform dilatation of upper part of 
nasal duct, lodged in the groove formed by lachrymal bone and 
nasal process of superior maxillary; its walls are formed of fibrous 
elastic tissue covered in by tensor tarsi muscle and a fibrous ex- 
pansion from tendo-oculi attached to ridge of lachrymal bone, 
while internally it is lined with mucous membrane. 
Describe the nasal duct3. 
It is a membranous canal about three-fourths of an inch long 
extending from the termination of lachrymal sac through osseous 
nasal duct to inferior meatus of nose, passing in a direction down- 
ward, backward, and slightly outward, its lumen being narrowest 
about the midpoint; externally, it is composed of fibro-areolar 
tissue; internally, of mucous membrane continuous with that of 
nose and lachrymal sac, the epithelial coating of both being of cili- 
ated epithelium, that of the canaliculi of scaly cells. 
What is the valve of Hasner ? 
An imperfect valve of mucous membrane guarding the some- 
what expanded terminal opening of the duct into the inferior 
meatus of nose. 
The Ear 
Where is the auditory apparatus lodged ? 
In the petrous and mastoid portions of the temporal bone. 
Enumerate the divisions. 
, , . . ,, 
1 he External ear, comprising the 
Aur icle, ox pinna, 
. External auditory canal. 
Membrana tympani, 
Cavity of tympanum, 
Mastoid cells, 
Eustachian tube, 
, . . 
Middle ear, or tympanum, comprising 
Vestibule, 
Semicircular canals, 
Cochlea, 
Auditory nerve. 
_ , , , , . . . 
Internal ear, or labyrinth, comprising 310 
ESSENTIALS OF HUMAN ANATOMY. 
The External Ear. 
What is the auricle ? 
Its foundation is an expanded layer of fibro-cartilage, so disposed 
in ridges as to concentrate and direct the waves of sound into the 
external auditory canal, to which it is attached ; the cartilage is 
deficient at certain points where it is connected by fibrous tissue; 
it is covered with perichondrium, outside of which is thin, firmly 
adherent skin, containing sweat and sebaceous glands, and provided 
with short downy hairs. The various ridges and depressions are as 
follows: the 
Concha, the deep cavity leading into meatus; the 
Ti'agus, the pointed prominence in front of concha projecting 
back over meatus, bearing on its under surface tufts of hairs; the 
Antitragus, a small tubercle opposite tragus, separated by a deep 
notch, the incisura intertragica; the 
Helix, the external prominent margin of auricle; the 
Antihelix, a parallel prominence anterior to former, bifurcating 
above to form the 
Fossa of the antihelix; the . 
Fossa of helix, the narrow, curved depression between the helix 
and antihelix. 
What is the lobe or lobule of the ear ? 
The inferior, soft pendulous portion, formed of fat and connective 
tissue enclosed by integument. 
Describe the muscles of the external ear. 
The attolens aurem, attrahens aurem, and retrahens aurem, have 
been described on page 116. 
The muscles of the auricle, but slightly developed in man, are 
the 
He/icis major: a narrow, vertical band on anterior border of helix; 
Helicis minor: an oblique band at root of helix; 
Tragicus: a short, vertical band on outer surface of tragus; 
Antitragicus: stretching from outer part of antitragus to lower 
part of helix; THE MIDDLE EAR OR TYMPANUM. 
Transversus auriculae : radiating from posterior surface of con- 
vexity of concha to prominence caused by groove of helix; 
Obliquus auris: a few fibres passing from upper back part of 
concha to convexity immediately above. 
Give the vascular and nervous supply to the auricle. 
The arteries are Posterior auricular, from external carotid. 
Anterior auricular, branch of temporal. 
Auricular, branch of occipital. 
The veins accompany the corresponding arteries. 
The nerves are, Auricularis magnus, from cervical plexus. 
Posterior auricular, from facial. 
Auricular branch (Arnold’s) of pneumogastric. 
Auriculo-temporal, from inferior maxillary divi- 
sion of fifth nerve. 
Occipitalis major and minor. 
What is the external auditory canal ? 
It is an osseo-cartilaginous, oval, cylindrical canal, with greatest 
diameter vertical at external orifice, but reversed at tympanic end; 
it is narrowest at middle. About one and a quarter inches long, it 
is directed obliquely forward and inward, and slightly curved with 
convexity upward, and is lined by thin adherent skin, containing 
hair follicles, sebaceous and ceruminous glands in its cartilaginous 
portion. A narrow groove at the tympanic extremity, for insertion 
of membrana tympani, is sometimes called the sulcus tympanicus, 
interrupted above by the notch of Bivinus. 
What are the arteries and nerves ? 
The arteries are branches of posterior auricular, internal maxil- 
lary and temporal. 
The nerves come chiefly from auriculo-temporal branch of supe- 
rior maxillary division of fifth nerve. 
The Middle Ear or Tympanum. 
Describe the membrana tympani. 
It forms the outer wall of the tympanum, and is an oval, trans- 
lucent membrane placed obliquely at the bottom of external audi- 312 
ESSENTIALS OF HUMAN ANATOMY. 
tory meatus, with its anterior, shallow funnel-shaped surface facing 
downward, forward, and outward; at its upper anterior border is a 
white, pointed tubercle, formed by the short process of the 
while a yellowish-white stripe passing from this downward and 
backward toward the centre, indicates the handle of the malleus. 
During life, when illuminated, the membrana tympani presents a 
triangular light spot or “ cone of light,” having its apex at end of 
malleus handle, whence it spreads downward and forward, and a 
darker central portion, the umbo, or shadow. The upper anterior 
part bridging a small notch in the bony ring to which the mem- 
brane is attached (the notch of Rivinus), is laxer, consisting of 
loose connective tissue, vessels, and nerves, covered with skin and 
mucous membrane, and has received the name of the membrana 
fiaccida, or Shrapnell's membrane. 
Of what tissues is the membrana tympani composed ? 
Of the skin, which is derived from the lining of the meatus; of 
a fibrous layer, some of whose fibres radiate from near the centre 
to the circumference, others form a dense ring around the attached 
margin; and of mucous membrane, derived from that lining the 
tympanum. The handle of the malleus passes between the inner 
and middle layers—according to von Troltsch,it is received between 
the circular and radiating fibres of the middle coat; an anterior 
and a posterior pouch have also been described upon the posterior 
surface by von Trfiltsch, opening downward, formed by a “ dupli- 
cature of the membrana tympani extending from its border for- 
ward to the manubrium.” 
Describe the arterial supply of the membrana tympani. 
The deep auricular branch of internal maxillary supplies the ex- 
ternal layers forming a plexus, which communicates at the 
periphery with one in the mucous membrane formed from 
Tympanic branches of internal maxillary and internal carotid 
arteries, and by the 
Vidian, from internal maxillary, and 
Stylo-mastoid, from posterior auricular. 
Mention the nerves supplying the membrana tympani. 
To the external layer run filaments from the superficial temporal 
branch of the fifth, while the mucous layer is supplied by the 
tympanic plexus. THE TYMPANUM. 
313 
The Tympanum. 
Describe it. 
It is an irregular cavity, measuring about one-half of an inch 
antero-posteriorly, one-third of an inch vertically, and one-fifth of 
an inch transversely, situated in the petrous bone, compressed 
from without inward, being placed above the jugular fossa, having 
the carotid canal in front, the mastoid cells behind, the external 
meatus externally, and the labyrinth internally; it communicates 
with the pharynx by the Eustachian tube, and presents for exami- 
nation the following points; the 
Roof, a very thin plate of bone, indicated on cranial surface by 
a depression on posterior surface of petrous portion of temporal 
bone; the 
Floor, narrow, corresponding to jugular fossa, and presenting 
near inner wall a small foramen for Jacobson’s nerve-, the 
Outer wall, the membrana tympani and bony ring to which it is 
attached, presenting three small orifices, the 
Iter chordae posterius, opening in angle of junction between pos- 
terior and external walls, just behind membrana tympani on a 
level with its centre, for entrance of chorda tympani nerve ; the 
Glaserian fissure, just above and in front of bony ring giving 
origin to membrana tympani, for passage of laxator tympani muscle 
and some tympanic vessels, and the lodgement of the long process 
of malleus; the 
Iter chordae anterius or canal of Huguier, opening just above pre- 
ceding, for escape of chorda tympani nerve; the 
Inner wall is vertical, looking directly outward, and presents the 
Fenestra ovalis or oval window, a kidney-shaped opening leading 
into vestibule, closed by base of stapes with its ligament; the 
Fenestra rotunda or round window, below, at bottom of a funnel- 
shaped depression, opening into scala tympani of cochlea, closed 
by the membrana tympani secundaria ; the 
Promontory, a rounded hollow eminence—the first turn of the 
cochlea—situated between oval and round windows, and present- 
ing three grooves lodging branches of tympanic plexus; the 
Eminence of the aquceductus Fallopii, passes above oval window, 314 
ESSENTIALS OF HUMAN ANATOMY. 
along inner tympanic wall, to curve behind that opening nearly 
vertically downward along posterior wall; the 
Pyramid, a hollow conical projection, behind the oval window 
and in front of vertical portion of aqueeductus Fallopii, containing 
the stapedius muscle whose tendon escapes from its summit; a 
minute canal communicates with the aquseductus Fallopii trans- 
mitting the nerve to stapedius muscle ; the 
Posterior wall, presenting the 
Openings of the mastoid cells, one large and several smaller open- 
ings. The anterior wall, is wider above than below, corresponding 
with carotid canal, the thin bony partition being perforated by 
tympanic branch of carotid; it presents the 
Orifice of the canal for the tensor tympani muscle, which is situated 
above, close to aquaeductus Fallopii, on the summit of a small 
conical eminence, the anterior pyramid; the 
Opening of Eustachian tube, is immediately below preceding, sepa- 
rated by a thin horizontal bony plate, the processus cochleariformis. 
What are the ossicles of the tympanum ? 
Three bones forming a movable chain, passing between mem- 
brana tympani and oval window, called the 
Malleus or hammer, consisting of 
an oval head articulating with 
incus, a neck, a manubrium or 
handle, affording attachment near 
its root to tensor tympani mus- 
cle, a short process coming in con- 
tact with membrana tympani, and 
a processus gracilis or long process, 
lodged in the Glaserian fissure, and 
giving attachment to so-called 
laxator tympani muscle; the 
Incus or anvil, having a body 
articulating with malleus, a long 
process terminating in a rounded end, the os orbiculare, which 
articulates with head of stapes, and a short process attached to 
margin of opening into mastoid cells; the 
Fig. 109. THE TYMPANUM. 
315 
Stapes or stirrup, consists of a head articulating with os orbicu- 
lare, a neck receiving insertion of stapedius muscle, two branches 
or crura joining the oval base, which latter is connected with 
margins of oval window by ligamentous fibres. 
The suspensory ligament of the malleus, passing between tympanic 
roof and head of malleus: the 
Posterior ligament of malleus, or laxator tympani minor muscle of 
Sommering, passing from upper back part of external meatus to 
handle of malleus and processus brevis ; the 
Posterior ligament of the incus, passing between posterior tym- 
panic wall near margin of opening into mastoid cells and end of 
short process of incus ; the 
Suspensory ligament of the incus, descending from tympanic roof 
to incus, near its articulation with malleus ; the 
Annular ligament of stapes, connecting circumference of its base 
to margins of oval window; the 
Capsular ligaments, around articulations between incus and 
malleus, and incus and stapes, these joints having their surfaces 
coated with cartilage, and being provided with a synovial mem- 
brane. 
Other ligaments have been described under special names, as 
the anterior and external ligaments of the malleus, and the obtu- 
rator ligament of the stapes, this latter being a membrane filling 
up opening between crura of stapes.. 
Describe the ligaments of the ossicles. 
Describe the muscles of the tympanum. 
Tensor tympani: origin, under surface of petrous bone, cartilaginous 
Eustachian tube, its own osseous canal; insertion, handle of mal- 
leus near root; action, draws membrana tympani inward—i. e., 
increases tension-, nerve, from otic ganglion. 
Laxator tympani major: origin, spinous process sphenoid bone, 
and cartilaginous Eustachian tube; insertion, neck of malleus above 
processss gracilis; action, relaxes membrana tympani; nerve, tym- 
panic branch of facial. (Now called ant. ligament of malleus.) 
Laxator tympani minor : origin, upper back part external meatus ; 
insertion, handle of malleus and processus brevis ; action, relaxes 
membrana tympani. (Now called posterior ligament of malleus.) 316 
ESSENTIALS OF HUMAN ANATOMY. 
Stapedius : origin, from interior of pyramid; insertion, neck of 
stapes; action, compresses contents of vestibule; nerve, filament of 
facial. 
Describe arterial supply of the tympanum 
The tympanic branch of the internal maxillary enters by Gla- 
serian fissure and is distributed to membrana tympani (tympanic 
branch of carotid also supplies this), anastomosing with Vidian 
and 
Stylo-mastoid, from posterior auricular to back part of tympanum 
and mastoid cells. 
Petrosal, from middle meningeal, entering through hiatus 
Fallopii. 
Tympanic, from internal carotid. 
Vidian, from internal maxillary. 
Branch, from ascending pharyngeal passing up Eustachian tube. 
What nerves supply the tympanum ? 
The Tympanic branch of the glosso-pharyngeal (Jacobson’s nerve), 
which pierces floor of tympanum to supply fenestrse and mucous 
membrane, and aids in forming tympanic plexus; the 
Tympanic branch of facial, supplying stapedius muscle; the 
Branch from otic ganglion, supplying tensor tympani muscle. 
(The chorda tympani from facial, passing into tympanum by iter 
chordae posterius, emerging by iter chordae anterius, arching across 
cavity between handle of malleus and long process of incus; it is 
covered by mucous membrane and gives off no branches.) 
Describe the formation of the tympanic plexus. 
The tympanic branch of glosso-pharyngeal, or Jacobson’s nerve, 
divides into three branches, lying in grooves on the promontory, 
one passes forward and downward to join carotid plexus, another 
passes upward to join greater superficial petrosal nerve in hiatus 
Fallopii, the third passes upward and forward through petrous 
bone close to ganglionic enlargement of facial, from which it re- 
ceives a filament, and becomes the lesser superficial petrosal nerve-, 
the tympanic mucous membrane is supplied by branches from this 
plexus. THE TYMPANUM. 
Describe the Eustachian tube. 
It is about one and one-half inches long, passing downward, 
forward, and inward, the passage by which the air in the middle 
ear freely communicates with that in the pharynx, thus permitting 
free vibration, as the hole in the side of a drum does. It con- 
sists of about one-third bone, and two-thirds fibro-cartilage and 
fibrous tissue; the tympanic orifice measures about'one and one- 
half inch, the oval pharyngeal opening one-third inch. 
The osseous portion, is one-half inch long, commencing at lower 
part of anterior tympanic wall, gradually narrowing to terminate 
at angle of junction of petrous and squamous portions of temporal 
bone; the 
Cartilaginous portion is about one inch long, formed by a tri- 
angular plate of elastic fibro-cartilage curved upon itself into a 
partial tube, but interiorly the margins are not in contact, the 
defect being filled by fibrous tissue; the 
Mucous membrane is continuous with that of pharynx, and is 
covered by ciliated epithelium. 
Where is the pharyngeal orifice situated ? 
At upper lateral portion of pharynx behind posterior part of 
inferior meatus, just above the level of nasal floor. 
Has this tube any special muscles ? 
Yes, the following have been described: 
Spheno-salpingo-staphylinis: origin, sphenoid bone and cartilag- 
inous tube; insertion, convex external border of cartilage; nerve, 
internal pterygoid; action, abductor or dilator of tube. 
Salpingo-pharyngeus: a thin layer beneath mucous membrane, 
probably really a fascia. 
(The Levator pa/ati: origin, temporal bone and cartilaginous tube; 
nerve, pneumogastric ; insertion, osseous tube, cartilage, and mucous 
membrane; action, dilates tube transversely.) 
Give the arterial supply of the Eustachian tube ? 
The ascending pharyngeal, from external carotid. 
Branches of middle meningeal, from internal maxillary. 818 
ESSENTIALS OF HUMAN ANATOMY. 
Branch, from stylo-mastoid artery. 
The nerves are, in addition to those supplying muscles of tube 
(supra), from the fifth and seventh pairs and glosso-pharyngeal. 
The Internal Ear or Labyrinth. 
Name its divisions. 
The osseous labyrinth, consisting of 
Vestibule* (Fig. 110), 
Semicircular canals?,6?, 
Cochlea8. 
Utricle, 
Membranous semicircular 
canals, 
Saccule, 
Membranous cochlea. 
Membranous labyrinth, consisting of 
Internal auditory canal, at bottom of which the auditory nerve 
enters. 
Auditory nerve (eighth cranial, or portio mollis of seventh), 
with the 
Organ of Corti, what the retina is to the eye, viz., the terminal 
and receptive auditory apparatus. 
Describe the internal ear. 
It is formed by a series of cavities excavated in the petrous 
bone, communicating externally with middle ear by the round 
and oval windows, internally, with internal auditory meatus: 
within the osseous labyrinth, surrounded by the 
Perilymph, is the membranous labyrinth—filled with endolymph— 
upon which the auditory nerve filaments are distributed. 
Describe the various subdivisions of the osseous labyrinth. 
The vestibule is the common central cavity with which all parts 
of the internal ear communicate, placed behind cochlea in front of 
semicircular canals, at inner side of tympanum ; it is ovoid, 
measuring about one-fifth of an inch from before backward, as well 
as from above downward, and presents the- 
Fenestra ovalis, or oval window, on its outer wall, closed in the 
fresh state by base of stapes and its ligament; the THE INTERNAL EAR OR LABYRINTH. 
319 
Fovea hemispherical, a small, circular depression on its inner wall, 
perforated antero-inferiorly by several minute foramina for branches 
of auditory nerve, the perforated plate, 
called the macula cribrosa; the 
Pyramidal eminence, a vertical ridge 
behind macula cribrosa; the 
Aquceductus vestibuli, at back of inner 
wall, transmitting a small vein, and, ac- 
cording to some, containing a tubular 
prolongation of lining membrane of ves- 
tibule, ending in a blind end in cranial 
cavity between layers of dura mater; the 
Fovea semi-elliptica1, a transversely- 
oval depression on roof, separated by 
pyramidal eminence from fovea hemispherica; the 
Orifices of semicircular canals, these are five in number, opening 
behind; the 
Apertura scalce vestibuli cochleae, a large oval opening, is situated 
anteriorly. 
Describe the semicircular canals5,6/. 
They are three curved bony tubes, each describing the greater 
part of a circle, of unequal length, of a diameter of about one- 
twentieth of an inch, each lying at a right angle to the other two, 
and presenting at one end a dilatation, or ampulla, more than 
double the diameter of the tube ; the 
Superior semicircular canal5 is vertical, describes about two-thirds 
of a circle, passes at right angles to posterior surface of petrous 
bone, and forms a projection upon its anterior surface; its outer 
end is its ampulla, opening separately into vestibule; its inner un- 
dilated extremity joins with that of the 
Posterior semicircular canal6, opening by a common orifice at back 
of vestibule; this canal is also vertical, is nearly parallel to pos- 
terior surface of petrous bone, is the longest, the dilated extremity 
opening at lower back part of vestibule; the 
External, or horizontal semicircular canal"1, is the shortest, is di- 
rected outward and backward, is ampullated, and opens into vesti- 
bule just above oval window, its other extremity by a separate 
orifice at upper back part of vestibule. 
Fig. 110. 320 
ESSENTIALS OF HUMAN ANATOMY. 
The cochlea? is conical, somewhat resembles a snail-shell, forms 
the anterior part of the labyrinth, is placed almost horizontally in 
front of the vestibule, its apex directed toward the upper front 
part of tympanic wall, and its base corresponding to anterior perfo- 
rated depression at bottom of internal auditory meatus; it presents 
for examination the 
Modiolus, a central, conical axis, perforated by numerous canals 
for filaments of cochlear branch of auditory nerve, its apex termi- 
minating in a delicate expanded 
lamella, like a funnel divided lon- 
gitudinally, called the infundibu- 
lum; extending from base to apex 
is a canal, the canalis centralis modi- 
oli, for a small nerve and artery; 
making two and one-half spiral 
turns around the modiolus is the 
Spiral canal8, about one-tenth of 
an inch in diameter, and one and a 
half inches long, narrowing from 
base to apex, there forming the 
cupola, where the scala tympani and scala vestibuli, formed by the 
lamina spira’.is, communicate by the helicotrema. 
The cochlea presents three openings, viz., the round window, 
communicating with tympanum, the oval one opening into vesti- 
bule, and that of the aquseductus cochleae9; projecting from the 
modiolus is the 
Lamina spiralis osseals, a process formed of two bony lamellae, 
between which are numerous canals for nerve fibres, defective in 
last half turn of cochlea leaving an aperture, the helicotrema, and 
terminating by the hook-like hamular process*1; winding around 
the modiolus at the point of attachment of the lamina spiralis is 
the canalis spiralis modioli, lodging the enlargement of the cochlear 
nerve containing ganglion cells, called the ganglion spirale, whence 
come the nerve branches to the organ of Corti. 
J11' 
What is the scala vestibuli*- (Fig. Ill) ? 
It is that portion of the canal of the cochlea above the lamina 
spiralis and membrane of Reissner, communicating with vestibule THE INTERNAL EAR OR LABYRINTH. 
821 
below and scala tympani above, by the helicotrema; it is filled 
with perilymph. 
Describe the scala tympani*- *• 
It is that portion of the spiral canal below the lamina spiralis** ®> 
and membranous cochlea, terminating below inferiorly at the round 
window—which is closed by membrane, the membrana tympani 
secundaria—and communicating above with scala vestibuli at heli- 
cotrema; it is filled with perilymph. 
What is the aquseductus cochleae'*? 
A small canal transmitting a vein from cochlea to jugular vein, 
commencing at lower wall of scala tympani, and ending to inner 
side of carotid canal close to posterior surface of petrous bone. 
Describe and name the subdivisions of the membranous 
labyrinth. 
It consists of a series of closed membranous sacs containing endo- 
lymph; its various parts are called 
( Utricle, 
1 Saccule, 
The vestibule, consisting of the 
two membranous sacs, 
with the former of which communicate three 
Membranous semicircular canals. 
The utricle and saccule are separate, but are indirectly connected 
by a minute canal passing from saccule to the similar one from 
utricle, passing along aquseductus vestibuli to end by a blind pouch 
near posterior surface of petrous bone; the saccule communicates 
with scala media (or membranous cochlea) by the canalis reuniens. 
The endolymph in all parts is thus seen to communicate freely. 
Describe the utricle. 
It is an oblong, laterally compressed sac, filled with endolymph, 
placed in upper back part of vestibule in fovea semielliptica, com- 
municating behind with semicircular canals by five openings, and 
has distributed, chiefly at one part of its walls, numerous branches 
of the auditory nerve, at which point is a round mass of minute 
crystals of calcium carbonate, bound together by delicate fibrous 
tissue forming the otoliths, otoconia, or ear-stones; the thickening of 322 
ESSENTIALS OF HUMAN ANATOMY. 
the wall both of utricle and saccule, where the nerves penetrate, 
is sometimes called the macula acoustica. 
Fig. 112. 
What are the membranous semicircular canals ? 
They are three canals of the same shape but smaller than the 
containing osseous canals, to which they are fastened by numerous 
fibrous bands, conveying the auditory nerve filaments to the 
ampullae; lrke the osseous canals they have five orifices which 
open into the utricle. 
Describe the saccule. 
It is a globular sac, smaller 
than utricle, to which it is at- 
tached at one point, and lies in 
fovea hemispherica ; it is sur- 
rounded with perilymph, and 
indirectly communicates by a 
short canal with utricle by 
means of the blind canal pass- 
ing along aquaeductus vestibuli 
to terminate near posterior sur- 
face of petrous bone; and with 
membranous cochlea or scala 
media by canalis reuniens, a small passage connecting the two 
cavities. 
Fig. 113. 
What is the membranous cochlea00 (Fig. 113). 
More usually called scala media or ductus cochlearis (Fig. 113) THU INTERNAL EAR OR LABYRINTlf. 
323 
it begins by a blind extremity at lower anterior portion of vesti- 
bule, enters cochlea, where it forms in cross section a triangular 
canal, its base being outer bony walls of cochlea, its lower wall 
the membrana basilarisb, its upper the membrane of ReissnerT; it is 
filled with endolymph and contains the organ of Cortico, covered by 
the delicate membrana tectorial parallel with basilar membraneb. 
The periosteum on upper surface of osseous spiral lamina forms 
an elevation, the 
Limbus laminae spiralislls, which presents an upper and lower 
margin called respectively the labium vestibulare and labium 
tympanicum, the groove formed between these being termed the 
sulcus spiralis*. 
What is the membrane of Reissnerr? 
A delicate membrane stretched between outer wall of cochlea 
and periosteum of vestibular surface of osseous spiral lamina near 
commencement of limbus laminae spiralis118, forming the upper 
wall of membranous cochlea. 
What is the membrana basilarisb ? 
A thin membrane passing from labium tympanicum to bony 
wall of cochlea, where it expands into the triangular ligamentum 
spiraled. It forms the lower wall of membranous cochlea, sup- 
porting on its upper surface the organ of Cortico. 
Describe the membrana tectoria or membrane of Corti1. 
A delicate membrane passing from between labium vestibulare 
and attachment of the membrane of Reissnerr to outer wall of 
cochlea, running nearly parallel with basilar membraneb; some 
contend that it is free, resting upon the organ of Cortico, and in 
its fresh pulpy condition serves as a damper of vibrations. 
Describe the organ of Corti00. 
It consists of a complex body formed by a series of some three 
thousand arches roofing over a space called the zona arcuata, 
formed of rods and epithelial hair cells, lying upon the membrana 
basilarisb and covered by the membrana tectoriat; the 
Rods of Corti are disposed in two rows, the inner'1 and outerer 
rods, each rod with its swollen base resting upon the basilar 
membranebb, and its expanded upper end inclined toward and 
in contact with the opposite one, forming an arched canal filled with 324 
ESSENTIALS OF HUMAN ANATOMY. 
endolymph ; according to Waldeyer there are about six thousand 
rods in the inner row, and four thousand five hundred in the outer; 
a nucleated mass of protoplasm occupies the angle between the 
base of each rod and the basilar membrane; the 
Fig. 114. 
Hair celUa (Fig. 115) are epithelial cells with stiff hair-like 
cilia/'? disposed in three or four rows upon the superior surfaces 
of the outer rodsm to the number of about eighteen thousand, and 
in a single row upon inner rodscd numbering about thirfiy-three 
hundred; the 
Lamina reticularis (Fig. 115) is formed of several rows of small 
fiddle-shaped cuticular structures called phalanges, connected 
together and to heads of outer rods, forming 
ringsmno, through which project the hairs of 
the outer hair cells. 
Where does the auditory • nerve arise 
and to what parts of the ear is it 
distributed ? 
Its superficial origin is from groove between 
olivary and restiform bodies at lower border 
of pons ; its deep origin is threefold (1) from 
superior vermiformis process of cerebellum, 
and from (2) inner and (3) outer auditory 
nuclei formed chiefly by gray substance of 
posterior pyramid and restiform body, from 
which latter it receives fibres as it winds 
around it. Entering with facial nerve the 
internal auditory canal, at its bottom it di- 
vides into the cochlear and vestibular branches, 
both of which contain numerous ganglion cells ; the 
Vestibular division divides into three branches, the superior 
Fig. 115. ANATOMY OF INGUINAL HERNIA. 
325 
splitting into many filaments which pass through upper back part 
of bottom of meatus, enter the vestibule through macula cribrosa 
to be distributed to utricle and ampulla of external and superior 
semicircular canals; the middle branch passes through the open- 
ings of the fovea hemispherica to supply the saccule; the inferior 
passes to ampulla of posterior semicircular canal; the 
Cochlear nerve divides into numerous filaments at base of 
modiolus, which enter its canals, pass between the two plates form- 
ing the lamina spiralis, forming a plexus which contains gan- 
glion cells, and sends branches, it is thought, to communicate with 
the hair cells; the 
Intumescentia ganglioniformis Scarpa, is the gangliform swelling 
on the vestibular branch in the internal auditory canal; the 
Ganglion spirale is the gangliform enlargement on the cochlear 
nerve as it occupies the canalis spiralis modioli. 
Give the arterial supply of the labyrinth ? 
The internal auditory, a branch of basilar artery, enters with 
nerve the internal auditory canal, there to divide into a vestibular 
and cochlear branch; the 
Stylo-mastoid, from posterior auricular; occasionally 
Branches from occipital. 
What is the internal auditory canal? 
A canal about one-third of an inch long, passing outward from 
posterior surface of petrous portion of temporal bone to end in a 
cribriform partition perforated with numerous foramina, some of 
them arranged in a spiral-shaped depression, the 
Tractus spiralis foraminulentus, others in three groups in as many 
depressions; at the upper pa.rt is the commencement of the aquee- 
ductus Fallopii for the seventh or portio dura nerve. 
Anatomy of Inguinal Hernia. 
What is the inguinal canal? 
The canal passing downward and inward for one and a half 
inches which lodges the spermatic cord in the male, the round 
ligament in the female, pursuing a course parallel to Poupart’s 326 
ESSENTIALS OF HUMAN ANATOMY. 
ligament through or between the abdominal muscles, commencing 
at internal abdominal ring and terminating at the external ab- 
dominal ring.8 
Describe the internal abdominal ring. 
It is an ovoidal opening in the transversalis fascia13 midway 
between anterior superior iliac spine and spine of pubes, and about 
half an inch above Poupart’s ligament6. It is bounded above and 
externally by arched fibres of transversalis muscle10, below and 
internally by epigastric vessels13; from its circumference passes the 
infundibuliform fascia on to the spermatic cord, or round ligament. 
What is the external abdominal ring8 ? 
An obliquely triangular opening in the aponeurosis2 of external 
oblique muscle1, just above and to outer side of crest of pubes; 
from base to apex it averages one inch by half an inch transversely. 
It is bounded below by the crest of pubes, above by the curved 
aponeurotic intercolumnar fibres1, and on each side by the free 
borders of the aponeurosis called the internal5 and external columns6 
of the ring; from the margins of the ring passes on to the cord or 
round ligament, the intercolumnar fascia. 
Give the boundaries of the inguinal canal. 
Anteriorly, the skin, superficial fascia, aponeurosis of external 
oblique, and outer third of internal oblique muscles. 
Posteriorly, the triangular ligament, conjoined tendon11 of inter- 
nal oblique and transversalis muscles, transversalis fascia15, sub- 
peritoneal fat, and peritoneum. 
Superiorly, the arched fibres of internal oblique10 and trans- 
versalis muscles. 
Interiorly, the union of the transversalis fascia13 and Poupart’s 
ligament6. 
What is Poupart’s ligament6 ? 
The infolded, thickened margin of aponeurosis of external oblique 
muscle, extending from anterior iliac space9 to spine of pubes, from 
which it is reflected a short distance along the pectineal line, 
forming Gimbernat's ligament, while a triangular band of tendinous 
fibres attached by its apex to the reflected portion of Poupart’s ANATOMY OF INGUINAL HERNIA. 
327 
ligament along the pectineal line, passing inward beneath sper- 
matic cord behind the inner pillar in front of the conjoined ten- 
don, and interlacing with its fellow at the linea alba, is called the 
triangular ligament: the lower part of Poupart’s ligament forms 
the external pillar of the external abdominal ring6. 
Fig. 116. 
Describe the relations of the epigastric artery and the in- 
ternal abdominal ring. 
It passes between the transversalis fascia and the peritoneum 
along the lower inner margin of internal ring beneath the sper- 
matic cord. 
What is the cremasteric fascia ? 
A series of muscular loops connected by areolar tissue investing 
the spermatic cord, supposed to have been derived from the in- 
ternal oblique muscle during the descent of the testicle, and, of 
course, absent in the female. 
What is Hesselbach’s triangle ? 
A triangular space at lower part of inner surface of abdominal 
wall, bounded externally by the epigastric artery, internally by 
margin of rectus muscle, and below by Poupart’s ligament: the 
conjoined tendon stretches across the inner two-thirds of this space, 
the remainder being filled in by the transversalis fascia. 328 
ESSENTIALS OF HUMAN ANATOMY. 
What is an oblique inguinal hernia ? 
A protrusion of bowel, omentum, or both, following the course 
of the spermatic cord in the inguinal canal through both internal 
and external rings (when complete), the neck of the sac being to 
outer side of epigastric artery. 
What are the coverings of an oblique inguinal hernia ? 
Skin; superficial fascia; intercolumnar fascia; cremaster muscle12 ; 
infundibuliform fascia; subserous cellular tissue; and peritoneum 
forming sac. 
Where is the seat of stricture most apt to be? 
(1) At internal ring, (2) inguinal canal by fibres of internal 
oblique or transversalis muscles, (3) at external ring, provided it 
is not at thickened neck of sac, the most usual site in old hernice. 
What is a direct inguinal hernia ? 
One where the protrusion passes through some part of Hessel- 
bach’s triangle, passing directly through the external abdominal 
ring, the neck of the sac being internal to the epigastric vessels. 
What coverings has a direct hernia ? 
The same as an oblique, except that the transversalis fascia take 
the place of the infundibulform fascia, and the conjoined tendon is 
substituted for the cremasteric fascia, but this latter covering is 
probably a theoretical, not an actual one. 
Femoral Hernia. 
Describe the femoral or crural canal. 
It lies beneath Poupart’s ligament6, to inner side of femoral vein19, 
extending from femoral ring above to saphenous opening17 below : 
it is about half an inch long, closed above by the septum crurale, 
formed of condensed areolar tissue, and below by the cribriform 
fascia, a portion of the deep layer of the superficial fascia covering 
the saphenous opening: the 
Femoral or crural ring is an oval space between femoral vein and 
Grimbernat’s ligament, half an inch in diameter, larger in female FEMORAL HERNIA. 
329 
than in male, situated below and external to internal abdominal 
ring: it is closed by the septum crurale and a lymphatic gland ; the 
Saphenous opening17 is an ovoidal opening one and a half inches 
long by half an inch wide, below inner portion of Poupart’s liga- 
ment6, formed by the pubic portion11 of fascia lata passing behind 
the saphenous vein leaving a margin concave outward, while con- 
tinuous with it is a strong falciform process, the iliac portion of 
the fascia lata, the falciform process of Burns16, passing in front of 
the vein, its narrow pubic portion blending with the attachment 
of Poupart’s and Gimbernat’s ligaments; this is called Hey’s liga- 
ment16 : the opening is covered in by the cribriform fascia. 
Bound the femoral canal. 
Anteriorly, lie the transversalis fascia13, Poupart’s ligament6, and 
falciform process of fascia lata16; 
Posteriorly, iliac fascia, covering pubic portion of fascia lata; 
Externally, the fibrous septum separating it from femoral vein; 
Internally, the junction of the processes of the transversalis and 
iliac fasciae forming femoral sheath lying against outer edge of 
Gimbernat’s ligament. 
Describe the position of parts around the ring. 
The Spermatic cord in male, the round ligament in female, lie just 
above anterior margin; the ' 
Femoral vein19 lies upon its outer side; the 
Epigastric artery crosses upper outer angle of ring; the 
Obturator artery once in three and a half cases arises in common 
with epigastric, when it closely skirts around the upper and inner 
margins of the ring. 
Describe the septum crurale. 
It is a layer of condensed cellular tissue upon which lies a small 
lymphatic gland, closing the femoral ring. 
What is the crural sheath ? 
It is a continuation downward of the fascia transversalis in 
front, and of the iliac fascia behind the femoral vessels forming 
their sheath, divided by septa into separate compartments for 
femoral artery externally, femoral vein next, and leaving a third 
internally, the femoral canal. 330 
ESSENTIALS OF HUMAN ANATOMY 
Describe the deep crural arch. 
When present, for it is not infrequently absent, it is a band of 
fibres derived from transversalis fascia, crossing the front of, and 
adherent to the crural sheath, passing from the centre of Poupart’s 
ligament to the pectineal line behind the conjoined tendon. 
Where is the seat of stricture most apt to be ? 
At (1) junction of Hey’s and Gimbernat’s ligaments, (2) margin 
of saphenous opening, (3) neck of hernial sac. 
What are the coverings of a femoral hernia? 
They are Skin, Superficial fascia, Cribriform fascia, Crural sheath, 
Septum crurale, Subserous areolar tissue, Peritoneum forming sac. 
Perineum and Ischio-rectal Regions. 
What is the ischio-rectal region ? 
That portion of the outlet of the pelvis immediately behind the 
perineum containing the rectum, upon either side of which is a 
deep fossa filled with fat, the 
Jschio-rectal fossa5, of a triangular shape, between the end of 
rectumx and tuberosity of the ischium0 on each side; its base 
corresponds to the skin, and apex to point of division of obturator 
fascia and origin of anal fascia; its base measures about one 
inch, its depth two inches, being deepest behind, and is bounded 
internally, by sphincter anix, levator ani5, and coccygeus6 muscles; 
externally, by tuberosity of ischium0 and obturator fascia; in front, 
by line of junction of superficial and deep perineal fascia; and 
behind, by margin of gluteus maximus muscle11 and great sacro- 
sciatic ligament; the 
Internalpudic artery and nerve run about one and a half inches 
above margin of ischiatic tuberosity, becoming more superficial 
as they pass forward along inner margin of pubic arch; the 
Inferior hemorrhoidal vessels, occasionally large enough to give 
trouble after lithotomy, traverse the centre of each fossa. PERINEUM AND ISCH10- REC T AL REGIONS. 
381 
What is the perineum ? 
It is the anterior portion of the pelvic outlet, in front of ischio- 
rectal fossae, is of a triangular form, bounded, deeply, by rami of 
pubes and ischia, forming, superiorly, the pubic arch, and behind, 
by an imaginary line drawn between ischiatic tuberosities; the 
lateral boundaries, in adult, vary from three to three and one-half 
inches. 
Describe the muscles of the perineum. 
External sphincter anix: origin, tip of coccyxb and superficial 
fascia in front of bone; insertion, tendinous centre of perineum2: 
action, closes anus; nerve, fourth sacral. 
Internal sphincter ani: consists of an aggregation of the involun- 
tary circular fibres of intestine, forming a muscular ring two lines 
thick and one inch broad. 
Fig. 117. 
Sphincter tertius (Hyrtl): origin, sacrum, encircling rectum four 
inches above anus (not described by many anatomists). 
Accelerator urines1: consists of two symmetrical halves with median 
tendinous raphe; origin, central tendon of perineum2 and median 332 
ESSENTIALS OF HUMAN ANATOMY. 
raphe in front; insertion, fibres spread over front of triangular 
ligament, encircle the bulb and corpus spongiosum, spread over 
sides of corpora cavernosa, to which they are partly attached 
and partly terminate in a tendinous expansion covering dorsal 
vessels of penis; action, empties urethra after bladder ceases to 
contract, perhaps aids in erection of penis; nerve, perineal branch 
of pudic. 
Erector penis3: origin, inner surface of each tuberosity of 
ischium, surface of crus penis and adjacent portion of pubic 
ramus (Erector clitoridis in female arises from ischial tuberosity; 
inserted on side of crus clitoridis); insertion, by an aponeurosis into 
sides and under surface of each crus penis; action, maintains 
erection; nerve, perineal. 
Transversus perinei1: origin, inner front side of tuberosity of 
ischium ; insertion, tendinous centre of perineum (in female, side 
of sphincter vaginae); action, steadies perineal centre; nerve, peri- 
neal. 
Levator anib: origin, body and ramus of pubes posteriorly, inner 
surface of spine of ischium, from angle of division between ob- 
turator and recto-vesical layers of pelvic fascia; insertion, sides of 
apex of coccyxb, opposite muscle by median fibrous raphe, ex- 
tending from coccyx to anal margin, side of rectum (and vagina 
in female) blending with sphincter muscles, and side of prostate 
gland, uniting beneath it with opposite muscle mingling with exter- 
nal sphincter and transversus peronei muscles at perineal centre2; 
action, supports rectum, vagina, and pelvic viscera, with its fellow 
helps form the floor of the pelvis; nerves, inferior hemorrhoidal 
and fourth sacral. 
Compressor urethrae: origin, aponeurotic, from three-fourths of 
an inch of upper part of pubic ramus on each side ; insertion, each 
muscle divides surrounding urethra from prostate gland to bulb of 
urethra, uniting with the opposite muscle above and below this 
tube by a tendinous raphe; action, shut-off muscle; nerves, peri- 
neal. 
Coccygeus6: origin, by apex from spine of ischium and lesser 
sacro-sciatic ligament; insertion, by base into margin of coccyx 
and side of lowest segment of sacrum; action, raises coccyx; com- 
pletes pelvic floor behind; nerve, anterior division fifth sacral. PERINEUM AND ISCHIO-RECTAL REGIONS. 
833 
Sphincter vaginae: (in female) surrounds vaginal orifice, is homolo- 
gous with accelerator urinae in male—origin, central tendon of peri- 
neum ; insertion, corpora cavernosa of clitoris. 
Erector clitoridis, in female replaces the erector penis muscle. 
Describe the perineal fascise. 
The superficial layer of the superficial fascia, is thick, loose, loaded 
with fat and continuous with the fasciae of ischio-rectal and crural 
regions; the 
Deep layer of the superficial fascia is a thin, moderately strong, 
aponeurotic layer, continuous in front with dartos layer of scrotum, 
is firmly attached to the margins of the rami of ischium and pubes 
external to crura of penis as far back as ischial tuberosity, and 
passes down behind the transversus perinei muscles to blend with 
lower margin of the deep perineal fascia; the 
Anterior layer of the deep perineal fascia is attached above and 
laterally to pubic arch, subpubic ligament and rami of ischium and 
pubes beneath crura of penis, forming a dense membranous lamina, 
extending and attached to tendinous perineal centre, becoming 
continuous with deep layer of the superficial fascia behind trans- 
verse perineal muscles: it embraces and is continued forward on 
anterior extremity of membranous urethra, which passes through 
it one inch below symphysis pubis; the 
Posterior layer of the deep perineal fascia is attached like preceding, 
but more posteriorly, embraces back portion of membranous urethra 
and is continued backward over outer surface of prostate gland, 
the two layers forming the triangular ligament: the portion of 
urethra embraced between these layers is the membranous urethra; 
the 
Obturator fascia is a continuation of transversalis and iliac fasciae 
below a white band at level of a line passing from lower part of 
symphysis pubis to spine of ischium : it covers the internal obtu- 
rator muscle and is continuous with posterior layer of triangular 
ligament; the 
Recto-vesical fascia, or visceral layer of pelvic fascia, descends into 
pelvis upon upper surface of levator ani muscle, investing prostate, 
bladder, and rectum.  ESSENTIALS OF HUMAN ANATOMY. 
Describe Buck’s fascia. 
It is a moderately dense fascia investing the penis as far as glans, 
being a prolongation forward of deep layer of superficial fascia, 
blending with dartos layer of scrotum : it directs the urine forward 
into scrotum, penis, and upon abdomen when the urethra is rup- 
tured. 
What layers of fascia form the triangular ligament ? 
The superficial and deep layers of the deep perineal fascia accord- 
ing to the description of most authorities. 
What structures lie between the layers of the deep perineal 
fascia ? 
Membranous urethra, 
Compressor urethrae muscle, 
Subpubic ligament, 
Dorsal vein of penis, 
Cowper’s glands and ducts. 
Pudic vessels, 
Pudic nerves, 
Arteries and nerves of bulb, 
Venous plexus. 
What structures are exposed by the removal of the deep 
layer of the superficial fascia ? 
The erector penis muscles covering the crura of penis. 
The accelerator urinae muscle covering corpus spongiosum and bulb. 
Transversus perinei muscles. 
Transversus perinei arteries. 
Superficial perineal vessels. 
What parts are divided in lateral lithotomy ? 
Skin. 
Superficial fascia. 
Inferior hemorrhoidal vessels and nerves. 
Posterior fibres of accelerator urinae muscle. 
Transversus perinei muscle and vessels. 
Superficial perineal vessels and nerves, (probably) deep perineal 
fascia. 
Anterior fibres of levator ani. 
Part of compressor urethrae. 
Membranous and prostatic portions of urethra. 
Part of prostate gland (neck of bladder, according to Gross). PERINEUM ARD ISCHIO-EECTAL REGIONS. 
335 
What structures must be avoided in this operation ? 
In front, the bulb and its artery. 
Externally, pudic artery. 
Toward median line and posteriorly, the rectum. 
At neck of bladder, the entire division of lateral lobe and, there- 
fore, the capsule of prostate gland and venous plexus. 
Briefly describe the special points of interest connected 
with the female perineum. 
The perineal body is the point of junction of all the muscular 
and aponeurotic structures of perineum, forming a pyramidal mass 
of tissue extending for some distance up between rectum and 
vagina, upon the integrity of which depends the proper support 
afforded to the pelvic viscera by the floor of the pelvis 
The length of the female perineum is only about one inch, 
extending from posterior commissure to verge of anus: the accel- 
erator urines muscle is replaced by the sphincter vaginae encircling 
the vaginal outlet: the triangular ligament, formed essentially as 
in male, and perforated by the urethra, is much smaller. INDEX. 
Abdomen, 243 
muscles of, 129 
Abdominal cavity, 243 
regions, 245 
Absorbents, 184 
Acervulus cerebri, 196 
Acetabulum, 68 
Alveoli of lower jaw, 50 
of upper jaw. 43 
of the lungs, 258 
Amphiarthrosis, 92 
Anastomoses, 157,175 
Anatomy, general, 17 
descriptive, 17 
Angle of the jaw, 51 
of subscapular fossa, 76 
Annulus ovalis, 154 
Antihelix, 310 
Antitragus, 310 
Antrum of Highmore, 40 
Anus, 232 
Aorta, 158. 167,168 
Appendices epiploicse, 232 
Appendix auriculae, 154, 155 
ensiform, 65 
vermiformis, 231 
Aponeuroses, 115 
pharyngeal, 225 
Apophysis, 21 
Aqueduct of Sylvius (iter 3 tertio, 
etc.), 194, 195 
Aquaeductus cochleae, 36 
Fallopii, 36, 203 
vestibuli, 319 
Arachnoid membrane of brain, 186 
of spinal cord, 199 
Arbor vitas, 198, 282 
Arch, crural, deep, 330 
palmar, 166 
plantar, 175 
Areola of mammae, 286 
Arm, 78 
Arnold’s ganglion, 202 
Arteriae propriae renales, 263 
Arterial anastomoses, 175 
Arteries, helicine, 274 
hepatic, 168 
lingual, 161 
pharyngeal, 161 
sublingual, 161 
Arteries of the— 
ankle-joint, 112 
auditory canal, 311 
auricle, 311 
bone, 19 
choroid, 298 
elbow-joint, 104 
Eustachian tube, 317 
eye, 304 
eye-lids, 304 
hip-joint, 108 
iris, 296 
kidney, 263, 264 
knee-joint, 110 
labyrinth, 325 
larynx, 254 
lung, 259 
mammae, 287 
membrana tympani, 312 
nasal fossae, 291 
nose, 291 
oesophagus, 226 
ovaries, 286 
pancreas, 239 
penis, 274 
pharynx, 226 
retina, 299 
shoulder-joint, 103 
spleen, 240 
stomach, 000 
supra-renal capsules, 243 
testicle, 277 
thymus gland, 242 
thyroid gland, 241 
tympanum, 318 
uterus, 284 
wrist-joint, 105 
Arteriolas rectae, 264 
Artery— 
anastomotica magna, 173 338 
INDEX. 
Artery— 
aorta, 158, 167, 168 
arteria receptaculi, 162 
auricular, 161 
axillary, 165 
basilar, 164 
brachial, 165 
carotid (external), 161 
(internal), 162 
cerebral, anterior, 163 
middle, 163 
posterior, 163 
choroid, anterior, 166 
communicating, anterior, 163 
posterior, 163 
coronary, 159 
digital, 167, 175 
dorsalis hallucis, 174 
pedis, 174 
epigastric, deep, 171 
superficial, 171 
facial, 161 
femoral, 171 
gastric, 168 
gluteal, 170 
hemorrhoidal, 170 
hepatic, 168 
iliac, circumflex, 171 
external, 171 
internal, 169 
ilio-lumbar, 170 
infra-orbital, 162 
innominate, 159 
intercostal, 167 
lingual, 161 
lumbar, 169 
mammary, internal, 164 
maxillary, internal, 161 
meningeal, anterior, 162 
mesenteric, superior, 168 
inferior, 168 
obturator, 170 
occipital, 161 
ophthalmic, 162 
palmar arches, 166 
peroneal, 174 
pharyngeal, ascending, 161 
phrenic, 168 
plantar, external, 174 
internal, 174 
popliteal, 173 
profunda femoris, 173 
inferior, 165 
superior, 165 
Artery— 
pudic, deep external, 173 
superficial external, 173 
internal, 170 
pulmonary, 175 
radial, 166 
renal, 169 
sacral, lateral, 170 
middle, 169 
sciatic, 170 
spermatic, 169 
splenic, 168 
subcla’vian, 163 
subscapular, 165 
suprarenal, 169 
suprascapular, 164 
temporal, 161, 162 
thoracic, acromial, 165 
superior, 165 
thoracica alaris, 165 
longa, 165 
thyroid, superior, 161 
inferior, 164 
thyroidea ima, 159 
tibial, anterior, 173 
posterior, 174 
transversalis colli, 164 
tympanic, 162 
ulnar, 166 
uterine, 170 
vaginal, 170 
vertebral, 164 
vesical, 169, 170 
Arthrodial joints, 93 
Articulations, 92 
atlo-axoidean, 95 
carpal, 105 
carpo-metacarpal, 106 
costo-sternal, 98 
costo-transverse, 98 
costo-vertebral, 97 
metacarpo -metacarpal, 106 
metatarso - metatarsal ,113 
occipito-atloid, 94 
occipito-axoidean, 96 
phalangeal, of foot, 114 
of hand,107 
radio-ulnar, 104 
sacro-coccygeal, 100 
sacro-iliac, 99 
sacro-ischiatic, 100 
sacro-vertebral, 99 
scapulo-clavicular, 101 
scapulo-humeral, 102 INDEX. 
339 
Artery— 
stemo-clavicular, 101 
tarsal, 112 
tarso-metatarsal, 113 
temporo-maxillary, 96 
tibio-fibular, 110 
vertebral, 94 
Arytenoid cartilages, 250 
Atlas, 63 
Auricle, 310 
Axis, 63 
coeliac, 168 
optic, 292 
thyroid, 164 
visual, 292 
Azygos veins, 180 
uvulae, 122 
Bartholin, duct of, 221 
glands of, 280 
Bauhin, valve of, 231 
Bell, external nerve of, 206 
internal nerve of, 205 
Bladder, 266 
Bodies, Malpighian, 263 
Pacchionian, 186 
Body, ciliary, 296 
olivary, 196 
perineal, 335 
pituitary, 191 
restiform, 197 
Bone, astragalus, 90 
caleaneum, 90 
clavicle, 75 
coccyx, 72 
cuboid, 90 
cuneiform, 91 
ethmoid, 38 
femur, 85 
fibula, 89 
frontal, 23 
humerus, 78 
hyoid, 65 
ilium, 69 
incus, 314 
innominate, 68 
ischium, 70 
lachrymal, 44 
malar, 44 
malleus, 314 
maxillary, inferior, 49 
superior, 40 
nasal, 40 
Bone— 
occipital, 27 
os calcis, 90 
os magnum, 84 
palate, 45 
parietal, 25 
pectineal, 70 
peroneal, 89 
phalanges of foot, 92 
of hand, 85 
pisiform, 84 
pubic, 70 
sacral, 71 
scaphoid, 83 
scapula, 76 
semilunar, 83 
sphenoid, 30 
stapes, 315 
sternum, 65 
structure, microscopic, 18 
temporal, 34 
tibia, 88 
trapezium, 84 
trapezoid, 84 
turbinated, inferior, 47 
middle, 39 
superior, 39 
ulna, 80 
unciform, 84 
vomer, 48 
Bones of the body, 20 
of the carpus, 83 
of the foot. 90 
of the hand, 82 
of the leg, 88 
of the lower extremity, 85 
of the metacarpus, 84 * 
of the metatarsus, 91 
of the tarsus, 90 
of the trunk, 61 
of the upper extremity, 74 
Wormian, 20 
Bonnet, capsule of, 293 
Bowman’s membrane, 295 
Brain, commissures of, 192 
divisions of, 187 
points on base, 190 
on surface, 187-190 
ventricles, 192 
weights, average, 187 
Bronchi, 255 
Brunner’s gland, 230 
Bulb of corpus cavernosum, 273 
of corpus spongiosum, 273 INDEX. 
Bulbi vestibuli, 280 
Bulbs, olfactory, 191 
Burns, ligament of, 329 
Burs* of ankle, 149 
of hip, 108 
of knee, 110 
of shoulder, 102 
of wrist, 139 
Caecum, 231 
Calamus scriptorius, 197 
Calices of kidney, 261 
Canal, alimentary, 224 
auditory, external, 311 
internal, 36 
carotid, 36 
central, of the cord, 200 
crural, 329 
dental, 41, 50 
femoral, 328 
Hunter’s, 144, 171 
hyaloid, 301 
infraorbital, 41 
, inguinal, 326 
of the modiolus, 320 
nutrient, 19 
palatine, 46 
sacral, 72 
spiral, of the cochlea, 320 
for tensor tympani, 37 
Vidian, 33 
Canal of— 
Huguier, 35 
Nuck, 383 
Petit, 302 
Schlfemm, 297 
Stilling. 301 
Canaliculi, 308 
Canalis reuniens, 322 
Canals, semicircular, 319 
membranous, 322 
Canthus, 306 
Capillaries, 158 
Capsule, internal, 194 
of Bonnet, 293 
of Glisson, 237 
of the lens, 301 
of Tenon, 293 
Capsules, suprarenal, 242 
Caput caeci, 231 
gallinaginis, 269 
Carpus, 83 
Cartilages of the larynx, 249 
Cartilages of Santorini. 250 
of tarsal, 306 
of Wrisberg, 251 
Cartilago triticea, 251 
Caruncula lachrymalis, 307 
myrtiformes, 280 
Cauda equina, 211 
Cavity, cotyloid, 68 
glenoid, of scapula, 78 
of the omentum, 246 
orbital, 55 
of reserve, 220 
sigmoid. greater, 80 
lesser. 80 
of radius, 82 
Cells auditory, 324 
ethmoid, 39 
hepatic, 237 
mastoid, 35, 314 
olfactory, of Scliultze, 201 
Cement, 218 
Cerebellum, ]y7 
Cerebro-spinal system, 185 
Cerebrum. 187 
convolutions of, 189 
fissures of, 187 
lobes of, 188 
Cervix of penis, 273 
of uterus, 282 
Chordae tendineae, 155 
Choroid tunic, 295 
plexus, 193 
Cilia, 307 
Circle of Willis, 163 
Circulus arteriosus iridis major, 
296 
iridis minor, 296 
venqsus, 287 
Clavicle, 75 
Clinoid processes, 30, 33 
Clitoris, 280 
Coccyx, 72 
Cochlea, membranous, 322 
osseous, 320 
Coeliac axis, 168 
Collar-bone, 75 
Colon, 231 
flexures of, 231 
Column® carne®, 155, 157 
papi llares, 155 
Columns of Bertin, 261 
of spinal cord, 199 
Commissure, optic, 200 
Concha. 310 INDEX. 
341 
Condyles, of femur, 86 
Condyles of humerus, 79 
Coni-vasculosi, 276 
Conjunctiva, 307 
Conus arteriosus, 154 
Convolutions of cerebrum, 189 
Coracoid process, 77 
Corium, 288 
Cornea, 294 
Coruicula laryngis, 250 
Cornua of thyroid cartilage, 250 
of the ventricles, 192 
Corona glandis, 273 
radiata, 195 
Coronoid process, 49, 81 
Corpora albicantia, 191 
cavernosa, 273 
quadrigemina, 192, 195 
striata. 192 
Corpus Arantii. 155 
callosum, 193 
dentatum of cerebellum, 
198 
of Olivary body, 196 
fimbriatu.m, 193 
highmorianum, 275 
luteum, 285 
spongiosum, 273 
Corpuscles, Malpighian, 240 
tactile, 288 
Corti, organ of, 323 
Cortical substance of kidney, 
261 
Cotyloid cavity, 68 
Coverings of the testicle, 275 
of hernia, 328, 330 
Cowper's glands. 272 
Crest of the ilium, 69 
lachrymal, 44 
nasal, 43. 47 
of the pubes, 71 
of the tibia, 88 
turbinated, 42. 46 
Cricoid cartilage, 250 
Crista galli, 38 
Crura cerebri, 191 
of clitoris, 280 
of penis, 273 
Crusta petrosa, 218 
Crypts of Lieberkiihn, 230 
Cuneiform cartilages, 251 
Cuneus, 190 
Cupola of cochlea, 320 
Cuticle, 287, 288 
DARTOS, 276 
Dentine, 218 
Derma, 288 
Descemet, membrane of, 295 
Diaphragm, 13.1 
Diarthrosis, 93 
Digestion, organs of, 216 
Disk, optic, 298 
Discus proligerus, 285 
Dorsum of scapula, 76 
Douglas’s cul-de-sac, 281, 283 
Duct, cystic, 238 
hepatic, 237 
lymphatic, 184 , 9 
nasal, 309 
pancreatic. 238 
of Bartholin, 221 
of Gaertner, 286 
of Mailer, 277 
of Rivinus, 221 
of Steno. 221 
of Wharton, 221 
of Wirsung, 238 
thoracic, 184 
Ducts, biliary, 237 
ejaculatory, 278 
Ductus cochlearis, 322 
communis choledochus, 238 
Duodenum, 229 
Dura mater of cerebrum, 186 
of spinal cord, 199 
I?AR, 310 
J internal. 318 
Earstones, 321 
Eminence, hypothenar, 141 
thenar, 141 
Eminentia collateralis (pes accesso- 
rius), 194 
Enamel, 218 
Enarthrosis, 93 
Endocardium, 157 
Endolymph, 318 
Endosteum, 19 
Epidermis, 288 
Epididymis, 276 
Epigastric region, 245 
Epiglottis, 251 
Epiphysis. 22 
Equator of eyeball 292 
Eustachian tube, 317 
Eye, 292 
its appendages, 306 342 
INDE X. 
Eyebrows, 306 
Eyelashes, 307 
Eyelids, 306 
Fallopian tubes, 284 
Fallopius, aqueduct of, 313 
hiatus of, 36 
Falx cerebelli, 186 
cerebri, 186 
Fascia, anal, 333 
x Buck’s, 334 
cremasteric, 327 
cribriform, 329 
dentata, 194 
intercolumnar, 326 
ischio-rectal, 333 
lata, 142 
lumbar, 131 
obturator, 333 
palmar, 138 
perineal, 333 
plantar, 150 
recto-vesical, 333 
Fasciae, 114 
of the perineum, 334 
Fauces, 221 
Femur, 85 
Fenestra ovalis, 313 
rotunda, 313 
Ferrein, pyramids of, 263 
Fibro-cartilage, 94, 97, 102, 107, 110, 
307, 310 
Fibula, 89 
Fimbriae, 284 
Fimbriated extremity, 284 
Fissure, auricular, 37 
calcarine, 188 
calloso-marginal, 188 
collateral, 188 
dentate, 189 
Glaserian, 35 
palpebral, 306 
parieto-occipital, 187 
pterygo-maxillary, 60 
of Rolando, 187 
of Sylvius, 187 
precentral, 187 
spheno-maxillary, 60 
sphenoidal, 53 
transverse, 189 
Fissures of cerebellum, 198 
of cerebrum, 187 
of liver, 234 
Fissures of spinal cord, 199 
Folds, palpebral, 307 
Fontana, spaces of, 297 
Fontanelles, 52 
Foot, 90 
Foramen for Arnold’s nerve, 37 
caecum, 24 
condyloid, 28 
ethmoidal, 25 
for Jacobson’s nerve, 37 
infra-orbital, 41 
inter-vertebral, 62 
lacerum anterius, 33, 53 
magnum, 27, 54 
mastoid, 35 
medium, 54 
mental, 49 
nutrient, 19 
obturator, 68 
of Monro, 193 
of Scarpa, 43 
of Stenson, 43 
of Winslow, 247 
olfactory, 38 
ovale, 31 
optic, 33 
orbital, 32 
palatine, 43 
petrosal, 36 
posterius, 54 
pterygo-palatine, 47 
rotundum, 31 
sacral,-71 
spheno-palatine, 46 
spinal, 63 
spinosum, 32 
stylo-mastoid, 37 
supra-orbital, 24 
supra-seapular, 77 
thyroid, 68 
"Vesalii, 32 
Foramina at the base of the skull, 54 
olfactory, 38 
orbital, 32 
spheno-maxillary, 60 
Thebesii, 154 
Forearm, 80 
Fornix, 193 
Fossa, canine, 40 
coronoid, 80 
digastric, 35 
digital, 86 
glenoid, 78 
hyaloid, 301 INDEX. 
Fossa, incisive, 40 
infra-spinous, 77 
ischio-rectal, 330 
jugular, 29 
lachrymal, 25 
navicularis of vulva, 281 
of penis, 270 
olecranon, 80 
ovalis, 154 
pterygoid, 33 
scaphoid, 33 
spheno-maxillary, 61 
sublingual, 50 
submaxillary, 50 
subscapular, 76 
supraspinous, 77 
temporal, 59 
zygomatic, 60 
Fossae, nasal, 58 
of the skull, 53 
Fourchette, 281 
Fovea centralis, 298 
hemispherica, 319 
semi-elliptica, 319 
Fraenulum, 196 
Fraenum preputii, 274 
Gartner, duct of, 286 
Gall-bladder, 238 
Ganglia, basic, 191 
cervical, 213 
of fifth nerve, 202 
of the sympathetic, 211-214 
Ganglion, Arnold’s, 211, 212 
Gasserian, 202 
impar, 211 
Meckel’s, 212 
of ribs, 211 
spheno-palatine, 212 
spirale, 320, 325 
Gasser, ganglion of, 202 
Gimbernat’s ligament, 326 
Ginglymus, 93 
Gladiolus, 65 
Gland, lachrymal, 308 
mammary, 286 
pineal, 196 
prostate, 271 
thymus, 242 
thyroid, 241 
Glands, Brunner’s, 230 
Cowper’s, 272 
ductless, 239 
Glands, gastric, 228 
intestinal, 230 
lachrymal, 308 
lymphatic, 184 
Meibomian, 307 
of Bartholin, 280 
of Tyson, 274 
sebaceous, 289 
solitary, 230 
sweat, 289 
Gians clitoridis, 280 
penis, 273 
Glenoid, 78 
Glisson’s capsule, 235 
Globus major, 270. 
minor, 276 
Glottis, 252 
Gomphosis, 93 
Graafian vesicle, 285 
Groove, bicipital, 79 
infraorbital, 41 
musculo-spiral, 79 
mylo-hyoid, 51 
naso-palatine, 49 
optic, 30 
pterygo-palatine, 47 
Gubernaculum testis, 278 
Gums, 217 
Gyrus, angular, 189 
fornicatus, 189 ( 
Hairs, 288 
Hamstrings, 146 
Hamular process, 33 
Hand, 82 
Haversian canals, 18 
system, 18 
Head of the humerus, 79 
of the ulna, 81 
Heart, 153 
Helicotrema, 320 
I Helix, 310 
; Henle, tubes of. 261, 263 
Hernia, femoral. 328 
inguinal, 325 
Hey, ligament of, 329 
Hiatus Fallopii, 36 
; Hilum of kidney, 261 
Hippocampus major, 193 
minor, 193 
! Horner’s muscle, 117 
Houston, folds of, 232 
i Huguier, canal of, 35 344 
INDEX. 
Humerus, 78 
Humor, aqueous, 300 
vitreous, 301 
Humors of the eyeball, 300 
Hunter’s canal, 144 
Hydatids of Morgagni, 277 
Hymen, 280 
Hypochondrium, 244, 246 
Hypogastrium, 246 
ILEUM, 69, 230 
Ilium, 69 
Inciaura intertragica, 310 
Infundibula of kidney, 261 
Infundibulum of brain, 191 
Inguinal regions, 245, 246 
Intestine, large, 231 
small, 229 
Internal capsule, 194 
Intumescentia ganglioniformis Scar- 
pae of seventh nerve, 325 
Iris, 296 
Ischium, 70 
Iter chord® anterius, 313 
posterius, 313 
etertioad quartum ventriculum 
194 
Ivory, 218 
« 
JACOB’S membrane, 299 
f / Jacobson’s nerve, 203 
Jejunum, 229 
Joint, ankle-, 111 
elbow-, 103 
hip-, 107 
rotators of the-, 144-14(5 
knee-, 108 
shoulder-, 102 
wrist-, 105 
Joints, motion in, 93 
structures of, 93 
260 
TABIA majora,-279 
J minora, 279 
Labium tvmpanieum, 323 
Labium vestibulare, 323 
Labyrinth, membranous, 321 
osseous, 318 
Lacteals, 184 
Lacunus magnus, 270 
Lacunae, 18 
Lacus lachrymalis, 30(5 
Lamellae, 18 
Lamina cinerea, 191 
cribrosa (of sclerotic), 293 
fusca, 294 
reticularis, 324 
spiralis, 320 
Laminae of cornea, 295 
Lancisi, nerves of, 193 
Larynx, 249 
Layer, dermoid, 288 
ganglionic, 299 
molecular, 299, 300 
Leg, 88 
Lens, crystalline, 301 
Lieberkiihn, crypts or follicles of, 230 
Ligament, annular, of foot, 149 
annular of hand, 139 
conoid, 102 
coronary, 110 
costo-xiphoid, 98 
cotyloid, 107 
crucial, of knee-joint, 110 
deltoid, 112 
falciform, 329 
Gimbernat’s, 320 
glenoid, 102 
ilio-femoral or Y, 107 
of Burns, 329 
of Hey, 326 
of Zinn, 301 
orbicular, 104 
Pou part’s, 129, 326 
rhomboid, 101 
round, of the liver, 234 
round, of the uterus, 283 
sacro-sciatic, 100 
stellate, 97 
stylo-maxillary, 97 
suspensory, of lens, 301 
of liver, 234 
of penis, 273 
of spleen, 240 
transverse, of hip-joint, 107 
trapezoid, 102 
triangular, of perineum, 334 
Ligaments of the bladder, 267 
broad, of uterus, 283 INDEX. 
345 
Lymph-spaces of eyeball, 304 
Lyra, 193 
Macula acoustica, 322 
lutea, 298 
Maculaa cribrosae, 325 
Malleolus, 88. 89 
Malpighi, bodies of, 240 
pyramids of, 261 
Malpighian corpuscles, 263 
tuft, 263 
Mammae, 286 
Manubrium of the malleus, 314 
of the sternum, 65 
Marrow of bone, 19 
Masses, lateral, of ethmoid, 39 
Mastoid process, 85 
Meatus auditorius externus, 36 
internus, 36 
nasi, 59 
urinarius, 273, 280 
Meckel’s ganglion, 212 
Mediastinum, 260 
testis, 275 
Medulla oblongata, 196 
Medullary substance, 261 
Membrana basilaris, 323 
granulosa, 285 
pupillaris, 298 
Ruyschiana, 296 
sacciformis, 104 
tectoria, 323 
tympani, 311 
secundaria, 321 
Membrane, hyaloid, 301 
interosseous, 104, 111 
Jacob’s, 300 
limiting. 299, 300 
of Bowman, 295 
of Descemet, 295 
of Reissner, 323 
pituitary, 290 
Schneiderian, 290 
Shrapnell’s. 312 
vitelline, 285 
Membranes of brain, 186 
of the spinal cord, 199 
synovial, 93 
tarsal synovial, 114 
wrist synovial, 105 
Meridians of eyeball, 292 
Mesenteries, 248 
Meso-cephalon (pons Varolii), 195 
Ligaments, check. 96 
of the knee-joint, 108 
of the larynx,251 
of the liver, 234 
of the ossicles, 315 
of the ovaries, 284 
of the scapula, 102 
of the sternum, 99 
of the uterus, 283 
peritoneal, 248 
tarsal, 307 
Ligamentum latum pulmonis, 259 
mucosmn. 110 
nuchse, 124 
patellae, 108 
pectinatum iridis, 297 
suspensorium, 96 
teres, 107 
Winslowii, 109 
Limbus laminae spiralis, 323 
Line, inter-trochanteric, 86 
Linea aspera, 86 
ilio-pectinea, 70 
quadrati, 86 
Liquor Morgagni, 301 
Lithotomy, structures affected, 
334 
Liver, fissures of, 234 
lobes of, 235 
structure of, 237 
vessels of, 235' 
Lobe of the ear. 310 
Lobes of the cerebellum, 197 
of the cerebrum, 187 
of the liver, 235 
optic, 192 
Lobule of the ear, 310 
Lobules of the liver, 237 
of the lung,258 
Lob ft 1 us caudatus, 235 
quadratus, 235 
Spigelii, 235 
Lower, tubercle of, 154 
Lumbar regions, 245, 246 
Lung, broad ligament of, 259 
Lungs, 256 
Lunula, 288 
Lymphatics, 184 
hepatic, 237 
of lung,259 
of penis, 274 
of thymus gland, 242 
of trachea and bronchi, 256 
of uterus, 284 346 
INDEX. 
Metacarpus, 84 
Metatarsus, 91 
Modiolus, 320 
Monro, foramen of, 193 
Mons veneris, 279 
Morgagni, hydatids of, 277 
Mouth, 220 
Miiller, duct of, 277 
muscle of, 296 
Muscle of Bowman (ciliary), 296 
ciliary, 296 
cremaster, 327 
dilator pupillae, 298 
Horner’s, 117 
kerato-cricoideus, 253 
levator glandulte thyroideae, 241 
of Miiller, 296 
sphincter pupillae, 297 
triticeo-glossus, 253 
of the arm, 134 
of the auricle, 310 
of the back,123 
Muscles, double-bellied, 116 
of the abdomen, 129 
of the ear (external), 116 
of the epiglottis, 253 
of the Eustachian tube, 317 
of the eyeball, 302 
of the face, 117,118,119 
of the forearm, 136 
of the foot, 150 
of the hand,140 
of the head,111 
of the hip, 144, 145 
of the larynx,253 
of the leg, 147 
of the neck,120 
of the palate, 122 
of the perineum, 331 
of the pharynx, 225 
of the shoulder, 134 
of the stomach, 227 
of the thigh, 142 
of the thorax, 132 
of the tympanum, 315 
Muscular fibre, 114 
Musculi pectinati, 154 
Naboth, ovules of, 284 
Nails, 288 
Nates of cerebrum, 196 
Neck of humerus, 79 
Nerve tissue, 185 
Nerve, abducens, 202 
Arnold’s, 37, 204 
auditory, 203 
Bell’s external respiratory, 
206 
internal respiratory, 205 
chorda tympani, 202, 313, 316 
circumflex, 206 
cochlear, 203, 320 
crural anterior, 209 
facial, 202 
genito-crural, 208 
glosso-pharyngeal, 203 
hypoglossal, 204 
ilio-hypogastric, 208 
ilio-inguinal, 268 
intercosto-humeral, 206, 208 
interosseous, 208 
Jacobson’s, 37, 203, 316 
laryngeal, 204, 254 
maxillary, inferior, 202 
superior, 202 
median, 206 
motor oculi, 201 
musculo-spiral, 207 
nonus or ninth pair, 204 
obturator, 209 
of Wrisberg, 206 
olfactory, 200 
ophthalmic division of fifth, 
202 
optic, 200 
par vagum, 204 
patheticus, 201 
phrenic, 205 
pneumogastric, 204 
portio dura, 202 
portio mollis, 203 
pudic, 209 
radial, 207 
spinal accessory, 204 
sympathetic, 211 
thoracic, 206 
trigeminus, 201 
tympanic, 203 
ulnar, 207 
vestibular, 203, 324 
Vidian, 213 
Nerve-fibres, optic, 200, 305 
Nerves of ankle-joint, 112 
of auditory canal, 311 
of auricle, 311 
of bladder, 269 
of chorofd, 296 INDEX. 
Odontoblasts, 220 
Odontoid ligaments, 95, 96 
process, 63 
(Esophagus, 226 
Omentum, 247 
Opening, saphenous, 329 
Opercula, 220 
Optic thalami, 192 
Ora serrata, 298 
Orbital cavities, 55 
Organ of Corti, 323 
of hearing, 310 
of Kosenmiiller, 286 
of sight, 292 
of smell, 290 
Organs of generation, female, 279 
male, 271 
of sense, 287 
of taste, 289 
of voice and respiration, 249 
urinary, 260 
Os calcis, 90 
orbiculare, 314 
planum (orbital of ethmoid), 39 
tine*, 282 
uteri, 282 
| Ossa innominata, 68 
triquetra, 20 
Osteology, 17 
Ossification, 20 
Ossicles of tympanum, 314 
Otoliths, 321 
Ovaries, 284 
Oviducts, 284 
Ovisacs, 285 
Ovules of Naboth, 284 
Ovum, 285 
PACCHIONIAN bodies, 186 
Palate, 221 
Palpebr*, 306 
I Pampiniform plexus, 278, 286 
| Pancreas, 238 
■ lesser, 239 
! Papilla, lachrymal, 306 
optic, 298 
Papillae of skin, 288 
' Parovarium, 286 
1 Pars ciliaris retinae, 299 
intermedia, of vulva, 281 
Peduncles of cerebellum, 195, 196, 
197 
Pelvis, 73 
Nerves, cranial, 200 
hepatic, 237 
of Eustachian tube, 318 
of elbow-joint, 104 
of eye, 304 
of eyelids, 304 
of eye-muscles, 303 
of hip-joint, 107 
of iris, 298 
of kidney, 265 
of knee-joint, 110 
of Lancisi, 193 
of larynx, 204, 254 
of lung, 259 
.of membrana tympani, 312 
of nasal fossae, 291 
of nose, 291 
of oesophagus, 227 
of ovaries, 286 
of pancreas, 239 
of penis, 274 
of pharynx, 226 
of shoulder-joint, 102 
of spleen, 241 
of stomach, 229 
of supra-renal capsules, 243 
of taste, 222, 290 
of testicles, 278 
of thymus gland, 242 
of tongue, 222 
of trachea and bronchi, 256 
of tympanum, 316 
of uterus, 284 
of wrist-joint, 105 
petrosal, 213 
popliteal, 210 
sciatic, 209 
spinal, 205 
splanchnics, 214 
thyroid, 241 
Nervous system, 185 
Neurilemma, 185 
Nipple, 286 
Nose, 290 
Notch, cotyloid, 68 
inter-clavicular, 65 
inter-condyloid, 87 
popliteal, 88 
sacro-sciatic, 70 
sigmoid, 49 
supra-orbital, 24 
supra-scapular, 77 
Nuek, canal of, 283 
Nymph*, 279 348 
INDEX. 
Pelvis of the kidney, 261 
Penis, 272 
Pericardium, 152 
Perilymph, 318 
Perineum, 331 
female, 335 
Periosteum, 19 
Peritoneum, 246 
Peronei muscles, 147, 149 
Pes accessorius, 194 
hippocampi, 194 
Petit, canal of, 302 
Peyer’s patches, 230 
Phalanges of ear, 324 
of foot, 92 
of hand, 85 
Pharynx, 224 
Pia mater of brain, 187 
' of spinal cord, 199 
of the testes, 275 
Pinna, or auricle, 310 
Plane, equatorial, 292 
meridional, 292 
Plantar arch, 175 
Plate, cribriform, 38 
orbital, 39, 41,44 
perpendicular, 38 
Pleura?, 259 
Plexus, brachial, 206 
carotid, 214 
cavernous, 214 
cervical, 205 
choroid, 193 
gastric, 215 
lumbar, 208 
pampiniform, 278, 286 
sacral, 209 
solar, 215 
splenic, 215 
tympanic, 316 
Plexuses of the sympathetic, 214, 
215, 216 
Pli courbe (angular gyrus), 252 
Plica semilunaris, 307 
Point, nodal, 292 
Poles of the eyeball, 292 
Pomum Adami, 249 
Pons Varolii, 195 
Portal system, 178, 235 
Porus opticus, 293 
Pouches of membrana tympani, 312 
Poupart’s ligament, 129, 326 
Prepuce of clitoris, 280 
of penis, 273 
Process, acromion, 77 
alveolar, 43, 50 
articular, 21 
auditory, 36 
basilar, 28 
clinoid, 30, 33 
condyloid, 28, 40, 70, 85, 86 
coracoid, 77 
coronoid, 50. 81 
ethmoidal, 48 
falciform, 329 
hamular, of cochlea, 320 
of pterygoid plate of sphe- 
noid, 33 
lachrymal, 48 
malar, 42 
mastoid, 35 
maxillary, 48 
mental, 49 
nasal, 42 
odontoid, 63 
olecranon, 80 
olivary, 30 
orbital, 39, 41, 45, 46 
palatine, 43 
pterygoid, 33 
sphenoidal, 46 
spinous, 32, 43, 47, 63, 70, 71 
styloid, 37 
transverse, 63 
turbinated, 39 
unciform, 39 
vaginal, 37 
vermiform, 197 
zygomatic, 34 
Processes, ciliary, 296 
clinoid, 30, 33 
of Ingrassias 32 
Processus cochleariformis, 37 
cerebello ad medullam (inferior 
peduncles), 197 
ad pontem (middle pedun- 
cles), 195 
ad testes, 196 
gracilis, 314 
Promontory of sacrum, 71 
of tympanum, 313 
Prostate gland, 271 
Prostatic urethra, 269 
sinus, 269 
Pterygoid processes, 33 
Pubes, 70 
Punctum lachrvmale. 306 
Pupil, 297 1 XD EX. 
349 
Pylorus, 227 
Pyramid, anterior, 196 
posterior, 197 
of tympanum, 314 
Pyramids of Ferrein, 263 
of Malpighi, 261 
Radius, si 
Rami of inferior maxillary, 50 
Ramus of ischium, 70 
of the pubes, 70 
Receptaculum chyli, 184 
Rectum, 232 
Regions of abdomen, 244 
Reil, island of, 188 
Reissuer, membrane of, 323 
Renal vessels, 263 
Rete mucosum, 288 
Rete testis, 276 
Retina, 298 
Ribes, ganglion of, 211 
Ribs, 66 
Ridge, mylo-hyoid, 51 
pterygoid, 32 
Rima glottidis, 252 
Ring, abdominal, 326 
crural, 328 
femoral, 328 
Rings and phalanges, 324 
Rivmus, duct of, 221, 222 
notch of, 311 
Rods and cones (Jacob’s), 300 
of Corti, 323 
Rolando, tissure of, 1-87 
Rosenmliller, organ of, 286 
Rostrum of the sphenoid, 31 
SAC, lachrymal, 309 , 
Saccule, 322 
Sacculus laryngis, 252 
Sacs of the peritoneum, 246 
Sacrum, 71 
Santorini, cartilages of (cornicula 
laryngis), 250 
Scala media, 322 
tympani, 321 
vestibuli, 320 
Scapula, 76 
Scarpa, foramen of, 43 
intumescentia gauglioniformis, 
325 
Schindelysis, 93 
Schlemm, canal of, 297 
Schultze, olfactory cells of, 291 
Schwann, substance of, 185 
Sclerotic, 293 
Scrotum, 275 
Sella turcica, 30 
Septum crurale, 329 
lucidum, 193 
nasi, 58 
pectiniforme, 273 
Sheath, crural, 329 
Shin, 88 
Shoulder-joint, 102 
-blade, 76 
Shrapnell’s membrane, 312 
Sight, organs of, 292 
Sigmoid flexure, 232 
Sylvius, aqueduct of, 36, 203, 313 
tissure of, 187 
Sinus aortici or sinus of Valsalva, 
156 
circularis iridis, 297 
of the kidney, 261 
of Morgagni (sacculus laryngis), 
252 
pocularis, 270 
Sinuses, 23 
sphenoidal, 31 
of Valsalva, 155, 156 
Skin,287 
Slit, nasal, 38, 58 
Smell, organ of, 290 
Space, anterior perforated, 191 
posterior perforated, 191 
Spaces, Fontana’s, 297 
Spermatic cord, 278 
Sphincter vesicae, 268 
Spinal cord, 198 
Spine, ethmoidal, 30 * 
of the ischium, 70 
nasal anterior. 43, 58 
posterior, 47 
of the pubes, 71 
of the scapula, 76 
of the sphenoid, 32 
of the tibia, 88 
Spines of the ilium, 69 
Spinous processes, 21 
Spleen, 239 
Spot, blind, 298 
germinal, 285 
light, 312 
yellow, 298 
Squamous, 22 350 
INDEX. 
Stars of Yerheyen, 264 
Steno’s ducts, 221 
Stenson’s foramina, 43 
Sternum, 65 
Stilling, canal of, 301 
Styloid, 22 
Stomach, 227 
Substance of Schwann, 185 
Sulci, 189 
Sulcus spiralis, 323 
tympanicus, 311 
Surface, auricular, 70 
trochlear, 79 
Sustentaculum tali, 90 
Sutura, 92 
Suture, baso-sphenoidal, 52 
coronal, 52 
lachrymo-ethmo-frontal, 52 
lambdoidal, 52 
masto-occipital, 52 
masto-parietal, 52 
petro-occipital, 52 
petro-sphenoidal, 52 
sagittal, 52 
spheno-parietal, 52 
squamo-parietal. 52 
squamo-sphenoidal, 52 
Sutures, facial. 52 
of the orbit, 56, 57 
of the skull, 51 
Sympathetic system, 211 
Symphysis, 92 
of inferior maxillary, 49 
Synarthrosis, 92 
Synchondrosis, 92 
Synovial membranes, 93 
TARSUS, 90 
1 Taste, nerves of, 290 
Taste-goblets, 289 
Taenia hippocampi, 193 
semicircularis, 193 
Teeth, 217 
Tendo-oculi, 307 
Tendons, 115 
Tenon, capsule of, 292 
Tentorium cerebelli, 186 
Testes, 274 
of the cerebrum, 196 
descent of, 278 
Thebesius, foramina of, 154 
Thigh, 85 
Thorax, 64 
Thyroid axis, 164 
cartilage, 249 
Tongue, 222 
Tonsils, 221 
Trachea, 254 
Tract, lateral, 197 
optic, 305 
• uveal, 297 
Tracts, olfactory, 200 
Tractus spiralis foraminulentus, 
325 
Tragus, 310 
Trigonum vesicse, 268 
Trochanters of femur, 85 
Trochlea, 22 
Tube, Eustachian, 317 
Tuber annulare (pons Yarolii), 
195 
cinereum, 191 
Tubercle, 21 
genial, 50 
of Lower, 154 
Tuberosities, 21 
of femur, 87 
of humerus, 79 
of ischium, 70 
maxillary, 40 
Tubes of Henle (convoluted tubes), 
261 
spiral, of Schachowa, 262 
Tubuli lactiferi, 286 
seminiferi, 276 
uriniferi, 262 
Tuft, Malpighian, 263 
Tunica albuginea, 275 
vaginalis, 275 
vasculosa, 275 
Tunics of eyeball, 293 
Tutamina oculi, 306 
Tympanum, 313 
Tyson, glands of, 274 
ULNA, 80 
Umbilical region, 245 
Umbilicus, 244 
Umbo, 312 
Urachus, 267 
Ureters, 265 
Urethra, 271 
bulb of, 270 
Uterus, 281 
masculinus, 270 
Utricle, 321 INDEX. 
351 
Uvea, 297 
Uvula, 221 
vesicae, 269 
\7"AGINA, 281 , 
V Vaginal, 22 
Valley of cerebellum, 197 
Valsalva, sinuses of, 155, 156 
Valve, Eustachian, 154 
ilio-csecal, 231 
mitral, 156 * 
tricuspid, 155 
of Bauhip, 231 
of Vieussens, 196 
Valves of Kirkring (valvuh* coi 
niventes), 230 
semilunar, 155 
Valvulse conniventes, 230 
Vas aberrens, 276 
deferens, 277 
Vasa efferentia, 276 
recta, 276 
vasorum, 158 
Vein, axillary, 179 
basilic, 179 
cephalic, 179 
jugular, 178 
femoral, 182 
iliac. 182 
median, 179 
popliteal, 182 
portal, 183 
radial, 179 
splenic, 183 
subclavian, 179 
supra-renal, 183 
ulnar, 179 
vena cava, 180, 183 
vertebral, 181 
Veins, 177 
azygos, 180 
cardiac, 183 
choroid, 296 
hepatic, 183 
iliac, 182 
innominate, 180 
interlobular, 264 
jugular, 178 
of bone, 19 
of head and neck, 178 
of lower extremities, 182 
of oesophagus, 226 
of supra-renal capsules, 243 
Veins of thymus, 242 
of trachea and bronchi, 256 
of the eye, 296, 298 
of the kidney, 265 
of the larynx,254 
of the lung, 259 
of the pancreas, 239 
of the penis, 274 
of the stomach, 229 
of the thorax, 181 
pulmonary, 183 
saphenous, 182 ' 
spinal, 181 
thyroid, 241 
uterine, 284 
without valves, 178 
Velum interpositum, 187, 193, 
194 
Venae comites, 177 
propriae renales, 265 
rectae, 264 
vorticosae, 296 
Venter of the ilium, 70 
of the scapula, 76 
Ventricle of the cord, 200 
fifth, 194 
fourth, 195 
of the larynx,252 
third, 194 
Ventricles, lateral, 192 
Verheyen, stars of, 264 
Vertebra prominens, 64 
Vertebrae, 61 
Verumontanum, 269 
Vesaluis, foramen of, 32 
Vesicle, germinal, 285 
Graafian, 285 
| Vesiculae seminales, 278 
Vestibule, 280 
of the ear, 318 
Vidian canal, 33 
nerve, 213 
Vieussens, valve of, 196 
Villi, 230 
I Viscus, 216 
! Viscera, covered by peritoneum, 
216 
partially, 248 
wholly, 248 
Vitellus, 285 
j Vocal cords, 252 
I Vomer, 48 
Vortex of heart, 157 
I Vulva, 279. 352 
INDEX. 
WALLS of the tympanum, 313 
Wharton’s duets, 221 
Whorl of heart, 157 
Willis, circle of, 163 
Wings of the sphenoid, 31, 32 
Winslow, foramen of, 247 
ligament of, 109 
Wirsung, duct of, 238 
Wormian bones, 20 
Wrisberg, cartilages of, 251 
nerve of, 206 
285 
V INN, zonula of, 301 
/j Zona pellucida, 285 
Zone, anterior vascular, 294 
Zonula of Zinn, 301 
Zygoma, 34, 60