Difference between revisions of "Talk:Book - Buchanan's Manual of Anatomy including Embryology 16"

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(Created page with "==CHAPTER XVI THE EYE== The eyeball is almost spherical. It consists of the segments of two spheres—namely, a large posterior or sclerotic segment, which is opaque, and...")
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of the ectodermal cells of the edge of the optic cup, which has extended forward  
of the ectodermal cells of the edge of the optic cup, which has extended forward  
in front of the lens, and the back of the iris receives a pigmentary covering {uvea)  
in front of the lens, and the back of the iris receives a pigmentary covering {uvea)  
from the pars iridica retince.  
from the pars iridica retince.
The organ of hearing is divided into three parts—the external,
middle, and internal ear.
External Ear.
The external ear consists of the auricle (or pinna) and the external
auditory meatus. The former has been already described (see p. 1294)*
The external auditory meatus extends from the bottom of the
concha to the membrana tympani, and is about 1 inch in length.
It consists of two parts—outer, or cartilaginous, and inner, or osseous.
The cartilaginous part, which is also fibrous, is about J inch in length,
and the osseous part, which lies within the petrous portion of the
temporal bone, is about § inch long. The widest part of the meatus
is its orifice, which is oval, the long measurement being vertica .
The narrowest part is situated in its osseous portion, about T mch
from the tympanic membrane, and it is known as the isthmus. There
is another constriction of the canal situated near the deep end of t e
cartilaginous part, and produced by a projection which is placed
antero-inferiorly. The chief direction of the canal is inwards and
slightly forwards. At first it is also inclined upwards, then backwards,
and finally downwards. . ,
The cartilaginous part is continuous with the cartilage of the auricle,
and is attached to the external auditory process of the temporal bone.
Its cartilage is folded so as to form a deep groove which is open at its
upper and back part, the cartilaginous deficiency being completed
by fibrous tissue. In the anterior wall of the cartilaginous part are
two clefts (called the fissures of Santorini ) which are occupied by fibrous
Ssuf In important and close inferior relation of the cartilaginous
meatus is the parotid gland (see Fig. 1027). ,
The osseous part has been described in connection with the temporal
hone (d IQ4) At its deep end there is a narrow groove, called the
sulcus tvmianicus, which forms about five-sixths of a circle, the
deficiency being placed superiorly, at the V^femporaf^The
rinp- ic completed by the squamous part of the temporal bone, me
tympanic membrane is set obliquely within the tympanic sulcus
being inclined in such a way that its front part is nearer the nudd
line of the body than its back, and its lower part nearer the middle
line than the upper. The floor and anterior wall of the meatus
consequently longer than the roof and posterior wall.
^ 1671
The meatus is lined with skin, which is continuous with that of
the auricle. In the osseous part of the canal the skin is very thin,
and is provided with vascular papillae, but is destitute of glands and
hairs.. It is reflected over the outer surface of the membrana tympani,
of which it forms the outer layer. In the cartilaginous part of the canal
the skin is thicker, and is provided with hairs, connected with the
follicles of which are sebaceous glands. In addition to these there are
convoluted tubular glands, similar in structure to sweat-glands, and
called the ceruminous glands, which secrete the ear-wax.
Blood-supply.—The arteries are derived from the posterior auricular
of the external carotid, the deep auricular of the first part of the maxil
Upper Part ofHelix
Lateral Ligament of the Malleus
Semicircular Canals
External Auditory
__ Cochlea
x , Tympanum
Tensor Tympani Muscle
Apex of Pet. Portion
of Temporal Bone
_Anterior Lig. of
the Malleus
-Internal Carotid
Pharyngotympanic Tube
Parotid Gland
Tip of Styloid Process of
Temporal Bone
Tympanic Membrane
Iug. 1027. General View of the Right Organ of Hearing (after
Hirschfeld and Leveill£).
The external ear and middle ear are seen in section.
iary, and the anterior auricular branches of the superficial temporal.
The veins follow the course of the arteries.
Lymphatics. These pass to the mastoid glands and to the preauricular lymphatic glands.
Nerves. The auriculo-temporal nerve gives two branches to the
meatus, upper and lower, which enter it by passing between the
cartilaginous and osseous walls. The upper branch supplies the skin
covering the upper part of the membrana tympani, while the auricular
branch (Arnold s nerve) of the vagus supplies that of the osseous
part of the canal in its lower and back part, and also that covering
the lower part of the membrana tympani.
Early Condition of the Meatus.—At birth the osseous part of the
canal is represented by the tympanic annulus and a small portion of
the squamous part of the temporal bone. It is connected by fibrous
tissue to the cartilaginous framework of the auricle, and within this
fibrous tissue the osseous canal is formed by two outgrowths from the
tympanic annulus.
Middle Ear.
I he middle ear, or tympanum, is an irregular space within the
petrous part of the temporal bone, which lies between the membrana
tympani externally and the outer osseous wall of the internal ear or
labyrinth internally. It is lined with mucous membrane, and it
communicates with the naso-pharynx by means of the pharyngotympanic tube, through which it receives air. It has three parts:
(1) the tympanum proper, or cavum tympani; (2) the attic, or epitympanic recess; and (3) the tympanic or mastoid antrum.
The tympanum proper (or cavum tympani) is situated between the
tympanic membrane and the outer wall of the internal ear. Its
contents are as follows:
1. A chain of ossicles (malleus,
incus, and stapes), with
their ligaments.
2. Muscles.
The vertical and antero-posterior diameters (inclusive of the attic)
are fully \ inch. The transverse measurement is from | to £ inch,
except opposite the centre of the membrana tympani, where it is
only T V inch, and the shape of its cavity may, perhaps, be visualized
by likening a cast of it to a biconcave disc about the size of a threepenny piece.
The tympanic cavity has six walls—lateral, medial, roof, floor,
anterior, and posterior.
The lateral wall is formed chiefly by the tympanic membrane,
which has the handle of the malleus fixed to it, and slightly by the
tympanic annulus, within the circumference of which there is a groove,
called the tympanic sulcus, in which the membrane is set. The tympanic annulus and sulcus are interrupted superiorly by a notch, called
the tympanic notch. In front of the tympanic annulus is the open,
inner extremity of the squamo-tympanic fissure, which lodges the
processus gracilis of the malleus, and transmits the tympanic branch
of the internal maxillary artery. At the inner end of the fissure is
the opening of the iter chordce anterius, by which the chorda tympani
nerve leaves the tympanum.
The (medial) wall (see Fig. 1028) separates the tympanum from the
internal ear or labyrinth. It is very irregular, and is formed by the
following parts :
1 The fenestra vestibuli. 3 - The promontory.
2. Projection of the facial canal. 4 - The fenestra cochleae.
5. The sinus tympani.
3. Nerves.
4. Bloodvessels.
5. Air.
The fenestra vestibuli is situated in a depression, called the fossa
ovalis, at the upper part of the inner wall, and it leads into the cavity
of the vestibule. It is irregularly oval, and is elongated from before
backwards. It is occupied by the foot-piece of the stapes, and the
annular ligament which connects the circumference of the foot-piece
to the margin of the opening, the margin being covered by cartilage.
The projection of the facial canal lies above the fenestra ovalis.
The canal, which contains the facial nerve, is here directed backwards,
and has walls of a paper-like thinness.
The promontory is seen below the fossa ovalis, between it and the
fossa rotunda, and slightly in front of both. It is a rounded promin
Sinus Tympam Outlet of Facial Canal at
Stylo-mastoid Foramen
kiG. 1028. Section through the Petrous and Mastoid Portions of the
Temporal Bone, showing the Tympanum and Mastoid Cells.
ence made by the first turn of the cochlea, and is grooved by the nerves
of the tympanic plexus.
The fenestra cochlese is situated in a funnel-shaped depression
called the fossa rotunda, below and behind the promontory. It leads
into the scala tympani of the cochlea, and in the recent state is closed
by the secondary membrane of the tympanum.
1 he sinus tympani is a depression behind the promontory, and
between the fossa ovalis and fossa rotunda. In close relation to this
is the ampulla of the posterior semicircular canal.
The roof of the tympanum is a thin plate of bone, called the tegmen
tympani, which forms part of the anterior surface of the petrous part
of the temporal bone.
The floor, narrower than the roof, is a thin plate of bone which
separates the tympanum from the jugular fossa.
The anterior wall is narrow, owing to the descent of the roof, and
the inclination towards each other of the outer and inner walls. In
it are the openings of two canals, the upper of which lodges the tensor
tympani muscle, whilst the lower is the osseous part of the pharyngotympanic tube. The two orifices are separated by the margin of the
processus cochleariformis. The carotid canal lies just in front of the
lower part of the anterior wall.
Fig. 1029.—Diagrammatic Outline of Tympanum and Associated
The posterior wall is formed by the anterior or tympanic surface
of the petrous part of the temporal bone. From above downwards
the following parts are seen: (1) the opening of the mastoid antrum,
which communicates with the attic of the tympanum, or epitympanic
recess; (2) a depression called the fossa incudis, receiving the short
process of the incus* (3) a small conical projection, called the pyramid,
at the summit of which is an opening for the tendon of the stapedius
muscle (posteriorly the canal within the pyramid, which contains the
Mastoid Antrum
Lateral Semicirc.C. ~ *
Pyramid •
Sinus Tympanum —
-Epitympanic Recess
-Site of Geniculate Ganglion
Fenestra Vestibuli
Fenestra Cochleae
Fir jo^o_ Diagram to show Course and Relations of Facial Canal on
' 'the Medial and Posterior Walls of the Tympanum.
stapedius muscle, passes downwards in the posterior wall of the
tympanum, and communicates with the descending part of the canal
which contains the facial nerve; this explains how the branch of that
nerve to the stapedius reaches the muscle); and (4) the iter chordae
posterius, for the chorda tympani nerve. .
Tympanic Membrane.-This is the membrane which closes the
inner extremity of the external auditory meatus. It is situated on
the outer wall of the tympanum, of which it forms the chief part, and
it is set for the most part in the sulcus tympamcus, which marks the
inner surface of the tympanic annulus. Superiorly, however, where
the ring is wanting, the membrane is attached to the tympanic notch
(of Rivinus). This part of it is thinner and looser than the rest, and
is called the membrana flaccida, or Shrapnell’s membrane. The
attachment of the membrana tympani to the sulcus is by a thickened
ring of fibres, called the annulus fibrosus. This annulus passes from
the extremities of the notch to the short process of the malleus in the
form of two bands, the anterior and lateral ligaments of the malleus,
which form the lower boundary of the membrana flaccida. The membrane is set obliquely in the tympanic sulcus, so that its lower part
forms an acute angle with the floor of the meatus externus, and its
upper part an obtuse angle with the roof of the passage.
Superior Ligament of Malleus
Head of Malleus
Insertion of Tensor Tympani
Chorda Tympani Nerve
Superior Ligament of Incus
Body of Incus
Attic of Tympanum
^ Short Process of
L ’\ST ^Posterior Liga^ ment of Incus
s ^_Long Process of
_Processus Orbicu
1 & • laris of Incus
y ' 0 _Handle of Malleus
_Membrana Tympani
Fig. 1031.—The Right Membrana Tympani, Malleus, and Incus
(Internal, Posterior, and Superior View) (Spalteholz).
The tympanic membrane is somewhat oval. In the vertical
direction it measures about 10 mm., and horizontally from 8 to 9 mm.
The handle of the malleus lies between the mucous and fibrous layers
of the membrane, and descends to a point a little below its centre,
where it ends in a small knob, from which the radiating fibres of the
membrane proceed. This knob is firmly attached, and, being directed
inwards, the membrane is consequently drawn inwards at that point,
and its outer surface presents a slight conical depression, the deepest
part of which is called the umbo.
Structure.— The membrane consists of three layers—external,
middle, and internal.
The external or cutaneous layer is very thin, and is derived from
the skin of the external meatus. It contains no glands, is freely provided with bloodvessels and nerves, and is covered by stratified
squamous epithelium.
The middle or fibrous layer forms the proper substance of the
membrane, and consists of fibrous tissue. The fibres are radial and
circular. The radial fibres lie beneath the cutaneous layer, and radiate
from the handle of the malleus to the annulus fibrosus. The circular
fibres are deep to the radial fibres, and are most numerous towards the
circumference of the membrane. Both sets of fibres are absent from
the membrana flaccida.
The internal or mucous layer is continuous with the mucous membrane of the tympanum, and is covered by a single layer of squamous
The membrana flaccida, pars flaccida, or Shrapnell’s membrane, has
cutaneous and mucous layers only. These are united by connective
tissue, which is so loosely arranged that the membrane is flaccid. This
part is very liable to perforation.
Cone of Light.—Extending from the knob, in which the handle of
the malleus terminates, downwards and inwards to the antero-inferior
margin of the membrana tympani there is seen a specially bright
reflection, triangular in outline, with the apex towards the umbo.
This is called the cone of light.
Arterial Supply of the Tympanic Membrane.—(1) Deep auricular
branch of the maxillary artery. This vessel, which passes through the
anterior wall of the external meatus, supplies the cutaneous layer. It
descends from the skin of the roof of the meatus along the course of the
handle of the malleus to the umbo, where it divides into branches
which radiate towards the circumference of the membrane. (2) The
stylo-mastoid branch of the posterior auricular; and (3) the tympanic
branch of the maxillary. The former artery enters the tympanum from
the facial canal, and the latter through the squamo-tympanic fissure.
Branches from them supply the mucous layer, and form an anastomotic
ring around the circumference of the membrane. The fibrous layer
receives its arterial supply from the vessels of the cutaneous and
mucous layers.
The veins join the external and internal jugular.
Nerve-supply.—(1) The auriculo-temporal of the mandibular, (2) the
auricular branch of the vagus, and (3) branches from the tympanic
Secondary Membrane of the Tympanum.—This membrane closes
the fenestra cochleae on the inner wall of the tympanum, and separates
the tympanic cavity from the scala tympani of the cochlea. It is
concave towards the tympanum, and, like the membrana tympani,
consists of three layers. The external layer is formed by the tympanic
mucous membrane; the middle layer is fibrous; and the internal layer is
formed by the lining membrane of the cochlea.
The mastoid antrum and mastoid air-cells are described with the
temporal bone on p. 188, while the Eustachian or pharyngo-tympanic
tube is dealt with on p. 1378.
Lateral Process
Long Process
Fig. 1032.—The Malleus.
1. anterior view; 2, posterior view.
Ossicles of the Tympanum.
The tympanum contains three small bones, arranged in the form
of a chain which extends from the membrana tympani to the fenestra
vestibuli. The bones are the malleus, the incus, and the stapes. The
malleus is related to the membrana tympani, the stapes to the fenestra,
and the incus occupies an intermediate position between these two.
The malleus is so named from its resemblance to a hammer. It is
composed of a head, neck, handle, and two processes, long and short.
T 2 The head is the upper, enlarged,
Facet for incus rounded end. Posteriorly it has
a saddle-shaped facet, directed
obliquely downwards and inwards,
for articulation with the incus in a
synovial joint. The neck is the
constricted part below the head.
The handle (; manubrium) is directed
downwards, inwards, and backwards
from the neck; it is compressed
from before backwards, slightly
curved, and ends in a knob. It
lies between the fibrous and mucous layers of the membrana tympani,
descending to a point a little below the centre of the membrane. It
is firmly attached to the fibrous layer by its periosteum. The tensor
tympani muscle is inserted into the inner part close to its root. The
long or anterior process (processus gracilis ), which is slender, springs
from the front of the neck, and is directed forwards and downwards to
the petro-tympanic fissure, where it is embedded in fibres which form
part of the anterior ligament of the malleus, and connect it to the
margins of the fissure. The long process is in the adult for the most
part replaced by fibrous tissue except close to the neck of the malleus.
In early life it is continuous with Meckel’s cartilage. The short or
lateral process is situated immediately below the long process. It is
directed laterally to the upper part of the
membrana tympani, with which it is connected by the annulus fibrosus. It is also
connected with the extremities of the notch
by the anterior and posterior malleolar
Ihe incus resembles an anvil. It consists
of a body and two processes—short and
long. The body is thick, somewhat four- ^ ~ Head ° f Sta fu
sided, and laterally compressed. Anteriorly y^ 08 '
it presents a saddle-shaped articular surface
for the head of the malleus, with which it forms a synovial joint.
The short process is directed backwards, is tipped with cartilage, and
articulates with the fossa incudis on the posterior wall of the tympanum. The long process is directed downwards and medially, behind
for Malleus
/ Short Process
Long Process
'*■' Lentiform Nodule for
Head of Stapes
and parallel to the handle of the malleus. Its lower extremity is bent
inwards, and becomes narrowed into a neck, upon which is placed a
disc-like knob of bone, called the os orbiculare, which is covered by
cartilage for articulation with the head of the stapes. In early life,
and up to the sixth month of intra-uterine life, this process forms a
separate ossicle.
The stapes resembles a stirrup. It has a head, neck, two crura,
and a foot-piece or base. The head is directed laterally, is concave
and covered by cartilage, and articulates with the processus lenticularis
of the incus. The neck is the constricted part which lies immediately
internal to the head. Posteriorly it gives
insertion to the stapedius muscle. The
crura are anterior and posterior respectively,
and spring from the neck. They diverge as
they pass inwards, and are attached to the
foot-piece near its extremities. The anterior
crus is straighter and shorter than the
posterior. The foot-piece or base is some- Malleus
what oval, is directed medially, and occupies incus,,
the fenestra ovalis, which it almost completely fills; its circumference is covered by
cartilage, being attached to the margins of
the fenestra by annular ligamentous fibres. Stapes-
The arch formed by the crura and foot-piece _ ~
is occupied by a delicate membrane, which tympanic Os
is attached to a slight groove on the inner sicles in Position.
aspect of the arch.
Development of the Tympanic Ossicles— The malleus and incus are usually
regarded as being developed from the proximal end of Meckel’s cartilage,
which forms the cartilaginous bar of the first or mandibular arch. According to
some authorities, however, the incus is developed from the hyoid bar. The stapes
is developed from the dorsal part of the hyoid bar of the second visceral arch.
Ligaments of the Ossicles.—The synovial joints between the malleus
and incus and between the incus and stapes are provided with thin
capsular ligaments. The ligaments which connect the ossicles to the
walls of the tympanic cavity are five in number, three of them belonging
to the malleus, one to the incus, and one to the stapes.
The ligaments of the malleus are anterior, lateral, posterior, and
superior. The anterior ligament is arranged as a fibrous band which
extends from the root of the long process to the petro-tympanic fissure,
through which it passes to be attached to the spine of the sphenoid
bone. The lateral ligament (or malleolar fold) extends from the
short process to the anterior extremity of the tympanic notch. The
posterior ligament extends from the short process to the posterior
extremity of the notch. The superior ligament extends from the head
of the malleus to the roof of the attic or epitympanic recess.
The ligament of the incus connects the short process, near its
posterior extremity, to the fossa incudis.
The annular ligament of the stapes connects the circumference of
the foot-piece, which is covered by cartilage, to the margin of the
fenestra vestibuli, which is also covered by cartilage.
Muscles of the tympanum are the tensor tympani and the stapedius.
Tensor Tympani— Origin .—(i) The cartilaginous part of the
pharyngo-tympanic tube; (2) the apex of the petrous part of the
temporal bone; and (3) the wall of the osseous canal through which
the muscle passes.
Insertion, —The medial aspect of the handle of the malleus close to
its root.
Nerve-supply.—A branch from the otic ganglion, and through it
from the internal pterygoid branch of the mandibular division of the
fifth cranial nerve.
The muscle consists of a fleshy belly, about inch long, and a
delicate tendon. In passing backwards to the tympanum it lies in a
canal, the entrance to which is situated within the petro-squamous
angle of the temporal bone. The canal is placed above the osseous
part of the tube, from which it is separated by the processus cochlearifor mis. On entering the tympanum the tendon of the muscle bends
sharply over the edge of the processus cochleariformis, and then passes
laterally to reach its insertion. The tendon forms very nearly a
right angle with the fleshly belly.
Action. —To render tense the membrana tympani by drawing
inwards the handle of the malleus, and along with it the membrane.
Stapedius Origin. —The wall of the canal within the pyramid, and
of the continuation of this canal in front of the descending part of the
facial canal.
The tendon emerges from the canal within the pyramid through a
small orifice on the apex.
Insertion. —The posterior aspect of the neck of the stapes.
Nerve-supply. —The facial nerve.
Action. To draw the head of the stapes backwards. The result
is that the front part of the foot-piece of the stapes is tilted away
from the vestibule, and its back part is pressed inwards towards the
Movements of the Ossicles.—The malleus and incus both act as
levers of the first kind, the fulcra of which are represented by an axis
passing backwards from the slender process of the malleus. When a
sound-wave presses the tympanic membrane inward, the handle of the
malleus travels inward with it, and the head of the malleus, or short
arm of the lever, moves outward. The upper part, or short arm of
the incus lever, must move out too, since it is attached to the head
of the malleus, and the long process moves inward, thus pressing the
stapes into the fenestra ovalis and compressing the perilymph in the
Ihe secondary membrane of the tympanum, stretched across the
fenestra rotunda, is bulged outward by the perilymph, thus allowing
vibrations to travel through that fluid.
Mucous Membrane of the Tympanum.—The tympanic mucous
membrane is continuous anteriorly with that of the naso-pharynx
through the pharyngo-tympanic (or Eustachian) tube. Posteriorly it is
prolonged into the mastoid antrum, and thence into the mastoid cells.
It forms the internal layer of the tympanic membrane, and the external
layer of the secondary membrane of the tympanum. It also furnishes
sheaths for the tendons of the tensor tympani and stepedius muscles,
and for the chorda tympani nerve. Two folds extend downwards from
the roof of the attic or epitympanic recess, one in front of and the other
behind the superior ligament of the malleus. The former is connected
with the head of the malleus, and the latter (sometimes described as
the superior ligament of the incus) with the incus.
Attic or Epitympanic Recess and its Pouches.—The part of the
tympanic cavity which lies above the level of the upper margin of the
tympanic membrane is called the attic or epitympanic recess, as distinguished from the atrium or tympanum proper. It contains the
head and neck of the malleus, and the body and short process of the
incus. These divide it incompletely into two compartments—outer
and inner. The outer attic is subdivided into two pouches—superior
and inferior. The superior pouch is partially separated from the
inner attic by the two mucous folds which have been already referred
to as descending from the roof of the attic in front of and behind the
superior ligament of the malleus. The inferior pouch of the outer attic
is known as the pouch of Prussak. It is bounded laterally by the
membrana flaccida, superiorly by the lateral ligament of the malleus,
which partially separates it from the superior pouch, and internally
by the neck of the malleus. The pouch communicates posteriorly
with the tympanic cavity by an opening which is situated a little above
the level of the bottom of the pouch. If fluid, therefore, should
accumulate in Prussak’s pouch, it may readily lead to perforation of
the membrana flaccida.
Two other pouches are present—namely, the anterior and posterior
recesses or pouches of Troltsch. These lie one in front of and the other
behind the handle of the malleus, and are produced by the fold of
mucous membrane which invests the chorda tympani nerve.
The tympanic mucous membrane is covered for the most part by
columnar ciliated epithelium, except over the ossicles and membrana
tympani, where the epithelium consists of a single layer of squamous,
non-ciliated cells.
The tympanic or mastoid antrum is supplementary to the tympanum proper, or cavum tympani, behind which it is situated. It
communicates by a large irregular opening with the attic, and is
lined with mucous membrane, which is continuous with that of the
attic and cavum tympani. Opening from the antrum there are the
mastoid cells, which are lined with mucous membrane, continuous
with that of the antrum.
The average measurements of the antrum are as follows: vertical,
about Q millimetres; antero-posterior, about n millimetres; and
transverse, about 8 millimetres. The roof is formed by the thin
tegmen tympani, which enters into the formation of the middle fossa
of the base of the skull, and is consequently related to the temporal
lobe of the cerebrum and its meninges. The genu and descending
limb of the sigmoid sinus lie behind the antrum, and a little farther
back is the cerebullum. The facial nerve, as it traverses the descending part of its canal, lies in the posterior wall of the cavum tympani,
close to the medial wall and in front of the mastoid antrum. This
part of the nerve is on a plane anterior to the mastoid process, and is
nearly flush with the opening of the antrum. The ampulla of the
lateral semicircular canal of the internal ear gives rise to a slight
eminence on the medial wall at its anterior part.
The lateral wall corresponds on the surface with the area of the
suprameatal triangle of Macewen, and is formed by the postmeatal
plate of the squamous portion of the temporal bone. For a description
of this triangle, which is the region selected for mastoidectomy , and also
for the mastoid cells, see the description of the temporal bone.
Summary of Important Structures closely related to the Mastoid Antrum.
1. Temporal lobe of cerebrum and its meninges (roof).
2. Genu and descending limb of sigmoid sinus, and farther back the cerebellum (posterior wall).
3 - Facial nerve (posterior wall of cavum tympani, close to medial wall and
nearly flush with antral opening).
4 - Lateral semicircular canal (anterior part of medial wall).
The upper part of the antrum communicates, as stated, with the
attic of the cavum tympani, but the lower part is shut off by bone from
the cavity of the cavum tympani.
The mucous membrane of the mastoid antrum is continuous with
that which lines the mastoid cells. Anteriorly it is also continuous
with the mucous membrane of the attic and cavum tympani or tympanum proper. The mucous membrane of the cavum tympani is
continuous anteriorly with that of the pharyngo-tympanic tube, and
the mucous membrane of the tube is continuous with that of the
naso-pharynx. This extensive and continuous tract of mucous
membrane is covered by columnar ciliated epithelium except in the
following regions: (1) the promontory; (2) the tympanic ossicles;
(3) the tympanic membrane; (4) the mastoid antrum; and (5) the
mastoid cells. In these regions the epithelium consists of a single
layer of squamous, non-ciliated cells.
It is of considerable importance to note that micro-organisms
may pass from the naso-pharynx through the tube into the cavum
tympani and attic, and thence into the mastoid antrum and mastoid
cells. Purulent affections of these regions may therefore readily be
caused in this manner. Such affections may subsequently involve
(1) the temporal lobe of the cerebrum and its meninges, (2) the genu
and descending limb of the sigmoid sinus, and (3) the internal ear or
Arteries of the Tympanum. —The principal arteries are: (1) the tympanic
branch of the maxillary, and (2) the stylo-mastoid branch of the posterior
auricular. The tympanic artery enters through the petro-tympanic fissure, and
supplies the membrana tympani and front part of the tympanum. The stylomastoid artery enters the facial canal through the stylo-mastoid foramen, and
passes from the descending part of the canal into the tympanum. It supplies
the back part of the cavity and the mastoid cells, and it forms, with the tympanic
artery, a ring round the circumference of the membrana tympani.
In addition to the foregoing two arteries, the following three arteries enter
the tympanic cavity: (1) the petrosal branch of the middle meningeal, which
enters from the facial canal, into which it passes through the hiatus; (2) the
tympanic branch of the ascending pharyngeal, which accompanies the nerve
through the tympanic canaliculus; and (3) the tympanic branch of the internal
carotid, which enters by a minute foramen on the posterior wall of the ascending
part of the carotid canal in company with a sympathetic twig from the carotid
The veins of the tympanum pass to the pterygoid plexus, the superior petrosal
sinus, the internal jugular vein, and the pharyngeal plexus.
Nerves of the tympanum are described on pp. 1325 and 1400.
Internal Ear.
The internal ear is the essential part of the organ of hearing, and
is known as the labyrinth from its remarkable complexity. It consists
of two parts—namely, the osseous labyrinth and the membranous
Osseous Labyrinth.
The osseous labyrinth is a cavity situated within the petrous part
of the temporal bone, and is divided into three parts—namely, the
vestibule, the semicircular canals, and the cochlea. These divisions
are lined with a delicate periosteum, between which and the contained
membranous labyrinth there is a clear fluid, called the perilymph.
Vestibule.—The vestibule is the central division of the osseous
labyrinth. The semicircular canals lie behind it, and the cochlea is
situated in front of it. In the lateral wall is the fenestra vestibuii, which
is occupied by the foot-piece of the stapes and its annular ligament.
The medial wall has anteriorly a depression called the fovea spherica
or spherical recess, which corresponds to the lamina cribrosa at the
deep end of the meatus auditorius internus. It is pierced by apertures
for the passage of filaments of the auditory nerve to the saccule.
Behind and above the fovea spherica there is a ridge, called the vestibular crest, which lies obliquely. Posteriorly it bifurcates, and
between its two divisions there is a small depression, called the cochlear
recess, in which are openings for nerve filaments to the canalis cochlese.
Anteriorly it becomes somewhat triangular, and forms a pyramid,
which is pierced by nerves to the utricle.
The roof of the vestibule, behind and above the crista vestibuii,
has an oval depression, called the elliptical recess, which encroaches on
the inner wall and lodges the recess of the utricle. It is pierced by
nerves to the ampulke of the superior and external semicircular canals.
Below the fovea elliptica is the opening of the aqueduct of the vesti
bule, which leads to the posterior surface of the petrous part of the
temporal bone about J inch external to the orifice of the meatus
auditorius internus. It transmits the ductus endolymphaticus and
a minute vein.
Anteriorly the vestibule communicates with the scala vestibuli
of the cochlea, and posteriorly are the five openings of the semicircular
Semicircular Canals.—The osseous semicircular canals are situated
behind the vestibule. They are three in number—superior, posterior,
Cupola of Cochlea
Petrous part of Tern- 5
poral Bone
Facial Canal
Superior Semicircular Canal
Fenestra Vestibuli
Lateral Semicircular
Posterior Semicircular
Fenestra Cochleae
_ Superior Semicircular Canal
Inner Wall of Canal '
of Cochlea
Lamina Spiralis
Crus Commune of Sup. and
Post. SemicircularCanals
Posterior Semicircular
Lateral Semicircular
Elliptical Recess
\ Crista Vestibuli
Spherical Recess
1 \ .
1 '
> Orifice of Aqueductus Vestibuli
Recessus Cochlearis
Fenestra Cochleae
Scala T.ympani Scala Vestibuli
Fig. 1035. —The Osseous Labyrinth of the Left Side (Lateral View).
A, entire; B opened (Hirschfeld and Leveille; B, modified).
and lateral—and they open into the vestibule by five circular apertures,
the contiguous ends of the superior and posterior canals having a
common orifice. Each canal forms about two-thirds of a circle, and
each presents at one end an enlargement, called the ampulla. The
superior semicircular canal occupies a vertical position, and lies transversely as regards the long axis of the petrous part of the temporal
bone, giving rise to the eminentia arcuata on its superior surface.
Its ampullary end (antero-external) opens independently into the upper
part of the vestibule above the ampullary orifice of the external canal.
Its non-ampullary end unites with the non-ampullary end of the
posterior canal to form the crus commune, and the two open by a
common orifice into the vestibule. The posterior semicircular canal
arches backwards towards the posterior surface of the pars petrosa,
with which it is almost parallel, and, like the superior, it occupies a
vertical position. Its ampullary end (inferior) opens independently
into the lower and back part of the vestibule, and its non-ampullary
end, as just stated, joins that of the superior canal. The lateral
semicircular canal arches outwards, and occupies a horizontal position.
Its extremities are independent of those of the other two canals,
and they open by separate apertures into the upper and back part
of the vestibule. Its ampullary end is in front.
Cochlea.—The osseous cochlea is situated in front of the vestibule.
It consists of a tube coiled spirally upon itself, like a snail s shell,
Fig. 1036. _Median Section of the Left Osseous Cochlea of Man
from Apex to Base (Arnold).
S.V. Scala Vestibuli
S.T. Scala Tympani
L.S.O. Lamina Spiralis Ossea
C.C. Central Canal of Modiolus
M.A.I. Internal Auditory Meatus
and is conical. Its base is opposite the lamina cribrosa at the deep
end of the meatus auditorius interims; and its apex, known as the
cupola is directed outwards and slightly forwards towards the canal
which contains the tensor tympani muscle. Its length from base to
apex is about i inch. It consists of (1) a winding tube, called the
spiral canal of the cochlea ; (2) a central pillar, called the modiolus,
round which the spiral canal turns; and (3) a thin plate of bone, called
the osseous spiral lamina, which winds spirally round the modiolus
and projects into the spiral canal of the cochlea. . .
The spiral canal of the cochlea (cochlear canal or tube) winds round
the modiolus which forms its inner wall. It describes two and threenuarter turns, and its basal turn or coil gives rise to the promontory on
the inner wall of the tympanum. At the cupola it ends in a blind
extremity. It gradually diminishes in size from base to cupola; its
length is about 32 millimetres; and its diameter is about 2 millimetres
at the base, where it is greatest.
The modiolus is the central pillar round which the spiral canal of
the cochlea turns, and it forms the inner wall of that canal. It commences at the cochlear area of the lamina cribosa at the deep end of the
internal auditory meatus, and extends almost to the cupola, gradually
tapering. It is traversed by minute canals for branches of the cochlear
division of the auditory nerve. One of these canals occupies the
centre of the modiolus, and is called the central canal of the modiolus.
This canal begins at the foramen centrale of the cochlear area of the
lamina cribrosa, and it transmits the nerve-filaments for the apical
coil. The other canals, which have no special name, commence at
the tractus spiralis foraminosus of the cochlear area of the lamina
cribrosa, and they transmit the nerve-filaments for the other coils—
middle and basal. At successive levels these canals change their
direction, and pass outwards to the attached margin of the lamina
spiralis, to be presently described. Here they coalesce and form a
winding canal, called the spiral canal of the modiolus, which lodges
the spiral ganglion or ganglion of Corti. From this canal secondary
canals for nerve-filaments pass into the lamina spiralis.
The osseous spiral lamina is a thin plate of bone, which winds
spirally round the modiolus, to which it is attached. It projects from
the modiolus into the spiral canal of the cochlea throughout the windings
of the latter, and it extends for about half-way towards the outer wall
of the cochlear canal. It divides that canal incompletely into two
passages or scalar —an upper or scala vestibuli, and a lower or scala
tympani, the commencement of which is at the fenestra cochleae.
Close to the cupola the lamina spiralis terminates in a hook-like process,
called the hamulus. The spiral lamina consists of two plates of bone,
between which there are canals for nerve-filaments, these canals being
offsets of the spiral canal of the modiolus, which, as has been said,
contains the spiral ganglion or ganglion of Corti. They extend to the
free margin of the spiral lamina. The free margin of the lamina
spiralis is, in the recent state, attached to the outer wall of the spiral
canal of the cochlea by means of the basilar membrane or basilar
lamina, and the scala vestibuli and scala tympani are now completely
separated, except in the region of the hamulus, where they communicate
through an opening, called the helicotrema.
The lamina cribrosa, at the deep end of the internal auditory
meatus, will be found described in connection with the temporal
bone (p. 190).
At the lower end of the scala tympani is the upper opening of the
aqueductus cochleae, which passes downwards and medially to the
posterior border of the petrous part of the temporal bone. It transmits
a small vein to the inferior petrosal sinus, and establishes a communication between the scala tympani and the subarachnoid space.
Membranous Labyrinth.
The membranous labyrinth is situated within the osseous labyrinth,
and its constituent parts receive the terminal branches of the auditory
nerve. It is separated from the periosteal lining of the osseous labyrinth by the perilymph, and it contains the fluid known as the endolymph. In the case of the vestibule and the osseous semicircular
canals the. membranous labyrinth corresponds more or less with
them; but in the case of the osseous cochlea it forms part of the septum
between the scala tympani and scala vestibuli, and contains a passage
called the membranous canal of the cochlea (ductus cochleae).
Fig. 1037. —Diagram of Membranous Labyrinth.
Vestibular Part of the Membranous Labyrinth.—The vestibule
contains two membranous sacs—namely, the utricle and the saccule
_which are in close contact, but do not communicate with each other
directly. These sacs contain endolymph.
The utricle is the larger of the two sacs, and into it the membranous
semicircular ducts open. It occupies the upper and back part of the
vestibule, a portion of it, known as the recessus utriculi, lying in the
fovea elliptica. Near the crista vestibuli the wall of this recess receives
fibres of the auditory nerve and is thickened, this part of it being called
the macula utriculi. From the anterior and medial part of the utricle
a minute canal, called the ductus utriculi («ductus utriculo-saccularis ),
passes to join the ductus sacculi, and so form the ductus endolymphaticus (see Fig. 1037).
The saccule, which is somewhat oval, lies in front of the utricle,
and occupies the fovea spherica, where it is near the opening leading
into the scala vestibuli of the cochlea. Through the openings of the
fovea spherica it receives filaments of the auditory nerve, and this
portion of the saccule, being thickened, is known as the macula sacculi.
Interiorly the saccule is connected with a small canal, called the
ductus reuniens, which opens into the canal of the cochlea, or ductus
cochlearis, not far from its closed vestibular end. From the posterior
part of the saccule a minute canal, called the ductus sacculi, passes off,
which is soon joined by the ductus utriculi, and so the ductus endolymphaticus is formed. This latter duct traverses the aqueductus
vestibuli, and, having reached the posterior surface of the petrous
part of the temporal bone, it ends in a small blind dilatation, called the
saccus endolymphaticus , which lies beneath the dura mater. The saccule
and utricle are thus indirectly connected by means of the ductus sacculi
and ductus utriculi; and the saccule communicates with the ductus
cochlearis by means of the ductus reuniens.
Semicircular Ducts.—The membranous semicircular ducts correspond in outline to the osseous semicircular canals, within which they
lie; they form about two-thirds of a circle, and each has an ampulla
at one end, which is situated within the ampulla of the osseous canal.
They are elliptical in transverse section, and open into the utricle by
five orifices, the non-ampullated ends of the superior and posterior
canals being united, so that these two open by a common orifice
forming the crus commune. The convex wall of each canal is attached
to the periosteal lining of the osseous canal, whilst the concave wall is
practically free from the osseous wall, and is bathed by the perilymph.
These canals contain endolymph.
Structure.—The walls of the utricle, saccule, and membranous
semicircular canals consist of three layers: an outer or fibrous layer,
which is vascular; a middle layer, or membrana propria, which is translucent; and an inner or epithelial layer. In each ampulla the middle
layer, or membrana propria, projects into the cavity of the canal from
the peripheral wall, this projecting part being known as the septum
transversum. It partially divides the interior of the ampulla into two
compartments, and its free margin, which is covered by the auditory
epithelium, is called the crista acustica or ampullaris. The epithelial
layer consists of a single stratum of squamous cells, except in those
regions to which the filaments of the auditory nerve are distributed. These regions are as follows: (i) the macula (acustica)
utriculi; (2) the macula (acustica) sacculi; and (3) the crista of each
The macula utriculi is the thickened part of the antero-inferior wall
of the recessus utriculi, and is lined with auditory epithelium. The
macula is covered by calcareous particles, called otoconia, which
consist of crystals of calcium carbonate. The macula sacculi is the
thickened part of the anterior wall of the saccule, and is also lined with
auditory epithelium covered by otoconia. The crista ampullaris, as
we have seen, is the free margin of the septum trailsversum in each
ampulla, and is covered by auditory epithelium.
The auditory epithelium is of the columnar variety, and consists of
two kinds of cells, auditory and sustentacular. The auditory cells are
nucleated, and each is provided at its free extremity with a slender,
tapering, hair-like filament, which projects into the cavity. These
filaments are sometimes spoken of collectively as auditory hairs, and
the cells are hence called hair-cells. Their deep extremities fall short
of the membrana propria. The sustentacular cells lie between the haircells, and are elongated and nucleated. Their deep extremities are
attached to the membrana propria, and their free extremities give rise
to a kind of limiting membrane. The auditory nerve-fibres pierce
the membrana propria, and, having lost their medullary sheaths, the
axons end in arborizations round the deep ends of the auditory or
hair cells.
Superior Semicircular Duct
Lateral Semicircular Duct i
Posterior Semicircular Duct
Facial Nerve
Crus Commune of Superior and
' l Posterior Semicircular Ducts
j r Ampulla
_ l Nerve to Ampulla
Nerve to Utricle
~ . Nerve to Saccule
_ Cochlear Nerve
Fig. 1038. —The Membranous Semicircular Ducts, showing the Distribution of the Branches of the Auditory Nerve to their Ampullae
Membranous Cochlea.—The membranous cochlea is situated within
the osseous cochlea, and fills the gap which is left by the lamina
spiralis. It consists of two membranes, the basilar membrane and the
vestibular membrane (membrane of Reissner, Fig. 1040), which enclose
between them the ductus cochlearis, or scala media. 1 he osseous
cochlea in the recent state is therefore divided into three spiral
passages—the scala tympani, the scala vestibuli, and the ductus
cochlearis. The scala vestibuli is continuous with the scala tympani
at the cupola through an aperture, called the helicotrema ; and at the
base of the cochlea it opens upon the anterior wall of the vestibule.
The scala tympani begins at the fenestra cochleae, and in the recent
state is separated from the tympanic cavity by the secondary membrane of the tympanum. The scala media, or ductus cochlearis,
communicates near its lower end with the saccule by means of the ductus
reuniens. The scala vestibuli and scala tympani contain perilymph,
which is continuous with the perilymph of the vestibule and osseous
semicircular canals. The scala media contains endolymph, which is
continuous with that of the saccule,
Basilar Membrane.—The basilar membrane extends from the free
margin of the lamina spiralis to the crista basilaris, or lower part of
the spiral ligament, a thickening of the periosteum of that part of the
outer wall of the cochlea which forms the outer wall of the scala media,
or ductus cochlearis. It separates the ductus cochlearis from the scala
tympani, and is divisible into two zones, inner and outer. The inner
is called the zona arcuata, and supports the spiral organ. The outer
is known as the zona pectinata, and extends from the foot-plates of
the outer rods of this organ to the crista basilaris. The basilar membrane consists of a homogeneous membrana propria, with fibres embedded in it, the fibres being most numerous in the zona pectinata.
Vestibular Membrane, or Membrane of Reissner.—This is a delicate
membrane which extends from the upper surface of the lamina spiralis
a short distance from its free margin to the outer wall of the cochlea,
where it is attached to the periosteum a little above the outer attachment of the basilar membrane. It separates the cochlear duct from the
scala vestibuli, and consists of very delicate connective tissue lined on
each side with a single layer of squamous epithelium.
Osseous Spiral Lamina
Vestibular Membrane
Basilar Membiane
Scala Vestibuli
Ductus Cochlearis
Sc' NYll ESy/: ,'-.;
| Scala Tympan*
Fig. 1039.
-Vertical Section of the Cochlea of a Fcetal Calf, showing
The scala media, or ductus cochlearis, is situated between the
basilar membrane and the vestibular membrane. It is triangular in
transverse section, and has a roof, an outer wall, and a floor. The
roof is formed by the vestibular membrane (see Fig. 1040). The
outer wall is the wall of the cochlea and its periosteum, between the
external attachments of the basilar membrane and the vestibular
membrane. The periosteum in this region is much thickened, and
forms the spiral ligament of the cochlea, the lower part of which gives
rise to the crista basilaris. The floor is formed by the basilar membrane, and a part of the upper surface of the lamina spiralis. It has
been seen that the basilar membrane separates the ductus cochlearis
from the scala tympani. The ductus ends above in a closed extremity
at the cupola, and it has a similar ending at the base of the cochlea.
Near its lower blind extremity it receives the ductus reuniens, by
which it communicates with the saccule.
It has just been shown that part of the floor of the cochlear duct
is formed by some of the lamina spiralis. In the recent state it is
of some thickness, which is due to a thickening of its periosteal
covering. This fibrous thickening forms the limbus laminae spiralis
(see Fig. 1040).
Its outer margin is crescentic, the deep notch being called the sulcus lamince
spiralis. The sulcus has two lips, upper and lower. The upper is called the
labium vestibulare, the upper surface of which is marked by several interlacing
prominences and grooves. At the free margin of this labium the prominences
assume the form of tooth-like projections, which are known as the auditory
teeth. The lower lip of the sulcus is called the labium tympanicum. It is continued into the basilar membrane, and is perforated by a great number of apertures
for the branches of the cochlear division of the auditory nerve.
Spiral Organ (of Corti).—Over the upper surface of the inner part
(zona arcuata) of the basilar membrane the epithelium undergoes
Fig. 1040.—The Organ of Corti (Wiedersheim, after Lavdowsky).
1. Spiral Ligament
2. Limbus
3. Sulcus Spiralis
4. Inner Rod of Corti
5. Outer Rod of Corti
6. Tunnel of Corti
7. Phalangeal Process of Outer Rod
8. Inner Hair-cells
9. Outer Hair-cells
10. Cells of Deiters
11. Lamina Reticularis
12. Cells of Hensen
13. Cells o Claudius
14. Spiral Ganglion
15. Cochlear Nerve
16. Nerve-fibres to Hair-cells
remarkable modification, and gives rise to the spiral organ or organ
of Corti. The constituent parts of this very complicated organ are as
1 The rods of Corti. 4. The cells of Hensen and of Claudius.
2 The auditory or hair cells. 5 - The lamina reticularis.
3! The cells of Deiters. 6. The membrana tectona.
The rods of Corti are arranged in two rows, inner and outer (see
Fig 1041). Each rod consists of a foot-plate or base, an intermediate
portion, and a head. The foot-plate, which is expanded, rests upon
the zona arcuata of the basilar membrane, and the foot-plates of the
inner rods are separated from those of the outer rods by a slight
interval. As the rods rise the intermediate portions of the inner and
outer rods incline towards each other, and the heads of the two sets
of rods come into contact. In this manner a triangular tunnel is
enclosed between the two sets of rods and the basilar membrane,
which is called the tunnel of Corti. This extends along the entire
length of the ductus cochlearis.
The inner rods are more numerous than the outer, there being from
5,000 to 6,000 of the former and about 4,000 of the latter. They
incline upwards and outwards. The head of each has a concavity on
its outer side, above and below which there is a projecting portion, so
that it resembles the upper extremity
of the ulna, with its great sigmoid
cavity and olecranon and coronoid
processes. The concavity on the head
of the inner rod receives the round
head of the outer rod. Finally, the
tic. 1041. A Pair of Rods of inner rods are shorter than the outer.
Corti from the Rabbit’s Coch- The ou + pr rn d<? lpcc nnmprrmQ
lea (Side View, highly mag- An ? ouler * oas j ^ re . Aess nui ? e 5 , 0US
nified) (Schafer, in Quain’s ? nd lon § er than the inner, and they
‘Anatomy’). ~ incline upwards and inwards. The
head of each is divisible into two
parts—inner and outer. Ihe inner part is round, and is received
mto the concavity on the outer aspect of the head of the inner rod.
The outer part is prolonged into a beak-like projection, called the
phalangeal process, which forms part of the lamina reticularis, to be
presently described.
The auditory or hair cells are arranged in two sets—inner and
outer. Ihe inner hair-cells lie internal to the row of inner rods, and
form a single row. They are from 3,000 to in number. Their
free extremities, which lie close to the heads of the inner rods, are each
provided with a tuft of short, hair-like filaments. The deep, nucleated
ends of the cells are related to the terminal arborizations of nervefibres. Internal to the row of inner hair-cells there are two or more
rows of columnar cells, which are continuous with the columnar
epithelium of the sulcus spiralis laminae. The outer hair-cells are
disposed in three or four rows external to the outer row of rods. They
are much more numerous than the inner hair-cells. Their free extremities, like those of the inner cells, are each provided with a tuft
of short, hair-like filaments, and their deep, nucleated ends are related
to the terminal arborizations of nerve-fibres.
1 he cells of Deiters, which are sustentacular, are situated between
the rows of outer hair-cells. Each cell is nucleated and contains a
slender filament, known as the sustentacular filament or phalangeal
process. This filament is attached by its base to the basilar membrane, and is prolonged into the tapering upper end of the cell. It
terminates in an expansion, which forms a phalanx of the lamina
reticularis, to be presently described.
The cells of Hensen are disposed as a continuous layer external
to the lamina reticularis.
THE EAR 1693
External to the cells of Hensen there are the cubical or columnar
cells of Claudius: these are merely an epithelial lining layer.
The reticular lamina extends between the heads of the rods of
Corti and the cells of Hensen. It consists of phalanges, which are
arranged in two (or more) rows—inner and outer. The phalanges of
the inner row are formed by the phalangeal processes of the heads of the
outer rods of Corti. The phalanges of the outer row (or rows) are
formed by the phalangeal processes of the cells of Deiters. Between
the phalanges there are openings through which the outer ends of
the outer hair-cells, with their crescentic tufts of hair-like filaments,
The membrana tectoria, or membrane of Corti, which is elastic,
is the most superficial structure in connection with the spiral organ.
It extends from the limbus spiralis near, and external to, the attachment of the vestibular membrane to the region of the outer hair-cells.
It covers (1) the limbus laminae spiralis; (2) the labium vestibulare,
- Hehcotrema
Scala Vestibuli
Membranous Spiral
Scala Tympani
Expansion of Cochlear Nerve
Fig. 1042.—Section of the Cochlea, showing the Distribution of the
Cochlea Branch of the Auditory Nerve (magnified) (Hirschfeld
and Reveille).
and the auditory teeth; (3) the sulcus laminae spiralis; (4) the inner
hair-cells; (5) the inner and outer rods of Corti; (6) the cells of Deiters;
and (7) the lamina reticularis.
Auditory Nerve.—The auditory nerve, within the meatus auditorius
internus, breaks up into two divisions—vestibular and cochlear.
The vestibular nerve, as it traverses the meatus auditorius internus, has a gangliform enlargement, the vestibular ganglion, and
divides into three branches. These enter the vestibule through the
foramina in the superior vestibular area of the lamina cribrosa at the
deep end of the internal meatus. They are distributed to the macula
utriculi and to the cristae acusticas of the ampullae of the superior
and external semicircular canals.
The cochlear nerve in the meatus auditorius internus divides into
two branches—one to the macula sacculi, and the other to the crista
of the ampulla of the posterior semicircular canal. The filaments of
the former, which has a gangliform enlargement, pass through the foramina in the inferior vestibular area of the lamina cribrosa, and the
latter passes through the foramen singulare in the lamina cribrosa.
The cochlear nerve, having parted with these two branches, breaks
up into filaments which pass through the foramina of the cochlear
area of the lamina cribrosa, and so reach the base of the modiolus
of the cochlea. They traverse the canals of the modiolus, from which
they pass into the canals between the two layers of the lamina spiralis.
In doing so they have to cross the spiral canal of the modiolus, which
is situated close to the attached margin of the lamina spiralis. This
canal contains a ganglion, called the spiral ganglion, which follows
the windings of the canal, and contains bipolar nerve-cells. As the
auditory fibres pass from the canals of the modiolus into those of
the lamina spiralis the course of each fibre is probably interrupted
by a bipolar cell of the spiral ganglion. The nerve-fibres, leaving
these bipolar cells, traverse the canals between the two layers of the
lamina spiralis. Having lost their medullary sheaths, they pass
through the foramina of the labium tympanicum on the outer margin
of the limbus spiralis, and enter the basilar membrane, where they
end in arborizations which are connected with the inner and outer
Blood-supply of the Labyrinth.—The labyrinth derives its blood
from the internal auditory, which is a branch of the basilar artery
or of the anterior inferior cerebellar. The vessel traverses the meatus
auditorius internus, and divides at its deep end into two branches—
vestibular and cochlear. The vestibular artery supplies the utricle,
saccule, and semicircular canals, and the cochlear artery supplies the
The veins of the labyrinth ultimately join to form one vessel, called
the internal auditory vein, which opens into the inferior petrosal
sinus. The aqueductus cochleae and the aqueductus vestibuli each
transmit a vein; that which passes through the former joins the inferior
petrosal sinus or the bulb of the internal jugular vein, and that which
passes through the latter opens into the superior petrosal sinus.
Development of the Ear.
Internal Ear—Membranous Labyrinth. —The membranous labyrinth is
developed from the surface ectoderm in a manner similar to the development
of the crystalline lens. Over a circumscribed area, corresponding to the upper
end of the first visceral cleft, and upon the side of the hind-brain, the ectoderm
becomes thickened and invaginated. A depression is thus formed, which is
called the auditory pit. This pit becomes deepened, its mouth becomes constricted, and its lips, coming together, unite. The auditory pit then becomes
transformed into a closed sac, called the auditory or otic vesicle, or otocyst.
The auditory vesicle now becomes isolated from the surface ectoderm, and sinks
into the adjacent mesoderm, taking up a position close to the side of the hindbrain.
The auditory vesicle, which is at first almost spherical, soon becomes pyriform, this being due to the formation of a process, called the recess of the labyrinth
or vestibule, which is prolonged from its dorsal wall. As this process lengthens
it gives rise to the ductus endolymphaticus, which occupies the aqueductus
vestibuli of the petrous portion of the temporal bone. The expanded terminal
part of the ductus endolymphaticus is called the saccus endolymphaticus, and it
lies underneath the dura mater. The ventral aspect of the vesicle gives off a
tapering diverticulum, which gives rise to the ductus cochlearis, or scala media,
of the cochlea. This duct describes a bend, within which lies the cochlear
ganglion of the cochlear division of the auditory nerve. As the duct elongates
it continues to bend in a spiral manner, and so the ductus cochlearis is formed.
The cochlear ganglion elongates, and follows the spiral turns of the duct, from
which circumstance the ganglion is known as the ganglion spirale.
The three semicircular ducts are developed from the upper or cephalic part
of the auditory vesicle, this part representing the future utricle. This portion
of the vesicle presents two folds—vertical and horizontal. From the vertical
fold the superior and posterior semicircular canals are formed, whilst the horizontal fold gives rise to the lateral semicircular canal.
The auditory vesicle now becomes transversely constricted, and is divided
into two sacs—large and small. The large sac is called the utricle, from which
the semicircular ducts have just been developed. The small sac is called the
saccule, from which the ductus cochlearis has been developed. The portion
of this duct which communicates with the saccule becomes constricted, and
forms the canalis reuniens of Hensen.
The constriction which completely divides the auditory vesicle into utricle
and saccule also involves the vesicular end of the ductus endolymphaticus, and
divides it into two ducts, called the ductus utriculi and ductus sacculi. This
arrangement constitutes the only communication which now exists between the
utricle and the saccule.
As stated, the cochlear ganglion, or ganglion spirale, of the cochlear division
of the auditory nerve lies within the spiral turns of the ductus cochlearis. As
the osseous cochlea becomes formed, the ganglion spirale comes to occupy the
spiral canal of the modiolus. The vestibular ganglion of the vestibular division
of the auditory nerve lies in the internal auditory meatus after the completion
of ossification.
The membranous labyrinth, hitherto considered, is entirely epithelial.
Certain of its epithelial cells undergo important specializations to fit them for
sensorial purposes. These cells form six groups in definite regions. These groups
are as follows: (1) The crista acustica ampullaris, of which there are three, one in
the ampulla of each of the three epithelial semicircular canals; (4) the macula
(1 acustica) utriculi’, (5) the macula ( acustica) sacculi', and (6) the spiral organ {of
Corti), specialized from the epithelial ductus cochlearis. The groups connected
with the ampullae of the semicircular canals, the utricle, and the saccule, receive
their nerve-fibres from the vestibular ganglion of the vestibular division of the
auditory nerve. The organ of Corti receives its nerve-fibres from the cochlear
ganglion, or ganglion spirale, of the cochlear division of the auditory nerve.
Osseous Labyrinth. —The membranous labyrinth is surrounded by mesodermic
tissue, which becomes disposed in four layers. These layers, from within outwards,
may be spoken of as (1) the connective-tissue layer, (2) the gelatinous layer,
(3) the perichondrial layer, and (4) the cartilaginous layer. The connectivetissue layer forms the connective tissue of the various parts of the epithelial
labyrinth. The fibrous tissue of the gelatinous layer acquires vacuoles, and gives
place to the various perilymphatic spaces, which contain a fluid called the perilymph. In the case of the cochlea, the scala vestibuli and scala tympani alone
contain perilymph, the cochlear duct containing endolymph. The perichondrial
layer forms the lining perichondrium of the periotic cartilaginous capsule, and
subsequently becomes the lining periosteum of the osseous labyrinth. The
cartilaginous layer forms the periotic cartilaginous capsule, which undergoes
ossification, and gives rise, amongst other parts, to the osseous labyrinth, which
jg q£ i ar ger size than the membranous labyrinth. The osseous semicircular canals
conform in shape to the membranous semicircular ducts, but are of larger size.
The osseous vestibule differs from the membranous vestibule in being a single
osseous case, whereas its contents are the utricle and the saccule.
Whilst the perilymph lies external to the membranous labyrinth, the interior
of the semicircular ducts, utricle, saccule, and scala media contain endolymph,
the latter being in communication with the saccule by means of the canal is
The middle ear or tympanum and pharyngo-tympanic tube (see p. 73 et seq.)
are developed from the tubo-tympartic recess of the pharynx. This is the widest
part of the early pharynx, opposite the second and third arches, and by the
time the embryo has reached the second month of development the recess is
definitely indicated; it projects laterally with its contained cavity, compressed
dorso-ventrally, widely open into the general pharyngeal cavity. Its roof
supports the otic capsule, while the outer parts of the first two visceral grooves
are seen in its floor, with the second arch between them. It is bounded in
front by the first arch, and caudally by the third arch. The first lateral pouch,
on its lateral edge, is in contact with the persistent upper end of the first outer
groove; the second pouch, which has lost contact, is at its postero-lateral angle.
The recess deepens, and the third arch grows forward, cutting off the outer part
of the cavity from the pharynx and narrowing the anterior part, which still
remains continuous with the pharynx; the outer and larger part is the early
tympanum, and the constricted front portion becomes the tube.
The otic capsule enlarges and chondrifies, and as it grows depresses the
inner part of the tympanum, slightly rotating it, so that its former roof now
becomes its inner wall, applied to the surface of the capsule. Its floor, also
rotated, now slopes downwards and medially, and is in close relation with the
meatal plate, a cellular ingrowth from the upper end of the first outer groove;
this has grown in below the tympanum, and by a later process of hollowing
forms the ectodermal lining of the outer meatus and membrane.
Meckel’s cartilage develops in the mesoderm of the first arch, therefore
antero-lateral to the recess, in front of the position of the first pouch. It sends
an extension over the pouch to invade the second arch area behind this, passing
under the floor between the endoderm and the meatal plate; this extension forms
the basis of the tympanic membrane and the manubrium, and its upper part probably also forms the incus. The hyoid bar (Reichert’s cartilage), the bar of the
second arch, is behind this, immediately in front of the second pouch; an exten
sion from its upper end over the roof gives rise to the stapes. The stapes becomes
associated with the cartilaginous capsule, which has enlarged considerably; the
enlargement extends postero-laterally, and leads to the fusion of Reichert’s bar
with the capsule (tympano-hyal) and the position of the remnant of the second
pouch in the fossula rotunda (fenestra cochleae).
The chorda tympani crosses the first pouch; the level of the early tympanum
might roughly be taken as extending up to this nerve. The higher level of the
adult cavity is attained by a later extension. In the early condition of the
tympanum, the malleus, incus, stapes, and chorda tympani nerve lie embedded
in the mesodermic tissue which intervenes between the epithelial or mucous
roof of the membranous tympanum and its osseous roof. This mesodermic
tissue disappears, and the mucous (originally epithelial) lining of the tympanum
now comes into direct contact with the malleus, incus, stapes, and chorda
tympani nerve, all of which it encloses within folds. Though these structures
apparently lie within the tympanic cavity, this is not their actual position. They
are really outside the cavity, inasmuch as they lie external to the mucous lining of
the cavity. This may be illustrated by stating that the handle or manubrium
of the malleus and the chorda tympani nerve do not lie in the tympanic cavity,
but are placed between the middle, or fibrous, layer and the internal, or mucous,
layer of the membrana tympani.
External Ear.— AThe external ear consists of (1) the external auditory meatus,
including the membrana tympani, and (2) the pinna.
The external auditory meatus is developed from the upper part of the first
external or ectodermic furrow, which corresponds in position to the first
internal visceral cleft.
The membrana tympani is developed from the closing membrane which
separates the first internal visceral cleft from the first external ectodermic furrow.
This closing membrane is a trilaminar structure. Its inner layer consists of
entoderm; its middle layer of mesoderm; and its outer layer of ectoderm. The
membrana tympani, which is developed from it, is therefore trilaminar. The
outer layer is ectodermic, and is continuous with the cuticular lining of the external
auditory meatus; the middle layer is mesodermic, or fibrous; and the inner layer
is entodermic, or mucous, and is continuous with the mucous lining of the
tympanic cavity.
The component parts of the pinna are developed from six projections, consisting of mesoderm, covered by ectoderm. These appear on the upper ends
of the first and second visceral arches, where these bound the upper part of
the first external ectodermic furrow, which gives rise to the external auditory
meatus. The helix is developed from two of these tubercles, and each of the
other four gives rise to the antihelix, tragus, antitragus, and lobule. The mesodermic tissue of the projections becomes differentiated into connective tissue
and cartilage, and the ectoderm covers these.
Terms still in common use, though now ‘discardedare included in this list,
with a certain number of proper names coming in the same category.
Abdomen, a word of uncertain derivation, but possibly from abdo,
I hide or conceal.
Aberrant, wandering from the normal
Acervulus, a little heap.
Acervulus cerebri, brain-sand.
Acetabulum, a vessel for holding
vinegar; a juggler’s cup. But
used by Pliny to signify hipsocket.
Acinus, any juicy berry with stones
— e.g., the grape; the kernel in the
Acrocephalous, having a pointed or
conical head.
Acromion, the point or summit of
the shoulder.
Acusticus, a, um, pertaining to sound,
or to the sense of hearing.
Adamantoblast, enamel germ cell.
Adductor canal, subsartorial canal.
Adenoid, glandular.
Aditus, an approach or access.
Adrenal, near to the kidney.
Advehens, carrying to.
Afferent, carrying to.
Agger, a mound or rampart.
Agminated, disposed in columns.
Ala, a wing.
Ala cinera, vagal triangle.
Albicans, white.
Albuginea, whitish.
Alcock’s canal, pudendal canal.
Allantois, sausage-like.
Alveolus, a little trough.
Alveus, a trough.
Amacrine, without a long fibre.
Ambiguus, dark, obscure.
Ameloblast, enamel germ.
Ammonis, cornu, horn of Ammon,
who was represented as having
the head of a ram.
Amphiarthrosis, literally, articulation on both sides. Secondary
cartilaginous joint (fibro-cartilage).
Ampulla, a flask.
Amygdala, an almond.
Anastomosis, literally, an outlet; the
communication of branches of
vessels with one another.
Anconeus, pertaining to the elbow.
Ankylosis, bony union between two
bones which are normally separate.
Annulus, a little ring.
Ansa, a handle, loop, or brace.
Ansa cervicis, ansa hypoglossi.
Anserinus, pertaining to a goose.
Antecubital, in front of the elbow.
Antibrachium, forearm.
Anticubital fossa, cubital fossa.
Anticus, in front, anterior.
Antinion, opposite to the inion.
Antrum, a cave or cavity.
Antrum of Highmore, maxillary
Antrum, mastoid, tympanic antrum.
Anus, a ring.
Aorta, literally, the lower end of the
trachea; a carrier.
Apertura piriformis, anterior aspect
of nose.
Aponeurosis, an expansion from a
Aponeurosis, lumbar, lumbar fascia.
Aponeurosis, pharyngeal, pharyngobasilar fascia.
Apophysis (‘ grow from ’), a process
or swelling on a bone.
Appendix ventriculi laryngis, saccule.
Aqueductus cerebri, aqueduct of
Aqueductus Fallopii, facial canal.
Arachnoid, like a spider’s web.
Arantii, corpus, nodule (in cusps of
aortic and pulmonary valves).
Archenteron, primitive intestine.
Arcuatus, curved.
Area acustica, vestibular area.
Areola, a small open place.
Arnold’s ganglion, otic ganglion.
Arnold’s nerve, tympanic nerve.
Artery, literally, an air vessel; the
trachea was known as the arteria
aspera; a bloodvessel which carries
the blood from the heart.
Arthrodia, from the Greek word
meaning * a joint ’; applied to a
gliding joint.
Arthrosis, plane joint.
Arytenoid, pitcher-like.
Ascending frontal convolution, precentral convolution.
Ascending parietal convolution, postcentral convolution.
Aspera, rough.
Asterion, a star.
Astragalus, the ankle-bone; a die
(pi. dice); talus.
Atlas, a support; refers to Atlas,
who carried the earth on his
Atresia, imperforation.
Atrium, the hall in a Roman house.
Attic, epitympanic recess.
Attollens, raising up, elevating.
Attrahens, drawing to or towards.
Auditory, pertaining to the organ, or
sense, of hearing.
Auerbach’s plexus, myenteric plexus.
Auricle, the external ear.
Auricle (O.T.), atrium (heart).
Auricular appendix (O.T.), auricle.
Azygos, without a pair, single.
Bacillary, pertaining to a small staff
or rod.
Balanus, an acorn.
Barba, a beard.
Bartholin’s duct (great duct of Rivini),
principal sublingual duct.
Basilar, belonging to the base.
Basilic, royal, important.
Basion, base.
Bechterew, nucleus of, superior
vestibular nucleus.
Bell, nerve of, nerve to serratus
Bellini, ducts of, terminal collecting
tubules of kidney.
Biceps, having two heads.
Bicornis, two-horned.
Bicuspid (teeth), pre-molar.
Bigelow, Y-shaped ligament of, iliofemoral ligament.
Biventer, having two bellies.
Bowman’s capsule, capsule of glomerulus.
Bowman’s membrane, anterior elastic lamina of cornea.
Brachium, the arm.
Brachium conjunctivum, superior
cerebellar peduncle.
Brachium pontis, middle cerebellar
Brachycephalic, short-headed.
Bregma, from a Greek verb meaning
‘ to moisten/
Broca, area of, parolfactory area.
Broca, band of, diagonal band.
Bronchiole, a little bronchus.
Bronchus, literally, a draught; the
Bryant’s triangle, (1) horizontal line
from anterior superior spine;
(2) vertical line from top of great
trochanter; (3) line joining anterior superior spine to top of
great trochanter.
Bubonocele, a variety of tumour in
the groin.
Buccinator, a trumpeter.
Bulla, a knob; a bubble.
Burdach, fasciculus of, fasciculus
Burns, falciform process of (ligament
of Hey), superior cornu of saphenous opening.
Burns’ space, suprasternal space.
Bursa, a sac containing fluid.
Bursa omentalis, lesser sac.
Cacumen, tip, peak, or end.
Caecum, blind.
Caeruleus, dark blue.
Calamus, a reed-pen.
Calcaneum, the heel.
Calcar, a spur.
Calcination, reduction to a powder
(or line) by heat.
Calcis, of the heel.
Calix, a cup or goblet.
Callosal convolution, gyrus cinguli.
Calloso-marginal fissure, sulcus cinguli.
Callosum, hard, thick.
Calvaria ( calva , the bald scalp), the
upper part of the skull.
Canalis reuniens, ductus reuniens.
Cancellated, lattice-formed, reticulated.
Canthus, the angle of the eye.
Capillary, pertaining to the hair;
a vessel of hair-like minuteness.
Capitellum, a small head.
Capsular, suprarenal.
Caput gallinaginis, urethral crest.
Caput medusae, varicose veins radiating from umbilicus in portal
Cardia, the opening of the stomach;
the heart.
Cardiac, pertaining to the heart
(originally to the stomach).
Cardinal, principal or chief.
Carina, a keel.
Carneae, pertaining to flesh.
Carotid, stupefying; or perhaps from
two Greek words meaning ‘ head ’
and ‘ ear.’
Carpus, the wrist.
Cartilages, alar, lower lateral cartilage.
Cartilages, lateral, upper lateral cartilage (of nose).
Cartilages, Santorini, of, corniculate
Cartilages, Wrisberg, of, cuneiform
Caruncula, a little piece of flesh.
Caruncula sublingualis, sublingual
Carunculae myrtiformes, carunculae
Cauda, a tail.
Caudate, tailed.
Caudate lobe (O.T.), tail of caudate
Cavernous, full of hollows or cavities.
Centimetre (cm.), § of an English
Cephalic, pertaining to the head.
Cerato, horny.
Ceruminous, pertaining to wax.
Chiasma, two lines placed like an X.
Choana, a funnel.
Choanse, posterior apertures of nose.
Choledochus, bile-receiving.
Chondral, pertaining to cartilage.
Choroid (Chorioid), like skin.
Cinereus, ash-coloured.
Cingulum, a small girdle.
Circumflexus, bent around.
Circumvallate papillae, vallate papillae.
Cisterna, a cistern or reservoir.
Clarke, posterior vesicular column of,
thoracic (dorsal) nucleus.
Claustrum, a bulwark, barrier, or
Clava, a club; gracile tubercle.
Clavicle, from clavis, a key, or possibly a hoop-stick.
Cleido-, pertaining to the clavicle.
Clinoid, like the knob of a bedpost.
Clitoris, from a Greek verb meaning
‘ I shut up ’ or ‘ enclose.’
Clivus, a slope.
Cloaca, a sewer or drain.
Coccyx, a cuckoo.
Cochlea, a snail.
Cochlea, membranous, duct of cochlea.
Cochleariformis, spoon-like.
Coeliac, pertaining to the belly.
Colliculus, a little hill.
Colliculus, quadrigeminal body.
Colliculus seminalis, urethral crest.
Colon, the great gut.
Columns, rectal (Morgagni), anal
Comes, a companion.
Comma tract, semilunar tract.
Complexus, literally, folded together;
Concatenatae, chained together.
Concatenate glands, deep cervical
(lymph) glands.
Concha, a shell.
Condyle (‘ knuckle ’), a small round
prominence covered by cartilage.
Coni vasculosi, lobules of epididymis.
Conjunctiva, connecting.
Conniventes, winking or blinking.
Conoid, cone-like.
Conoid tubercle, coracoid tuberosity.
Conus arteriosus, infundibulum.
Conus elasticus, crico-vocal membrane.
Convoluta, rolled together.
Coracoid, like a crow or raven.
Cord, vocal, false, vestibular folds.
Cord, vocal, true, vocal fold.
Cordiform, heart-shaped.
Cords (gangliated, lumbo-sacral,
etc.), trunks.
Cornea, horny.
Corniculum, a little horn.
Cornu ammonis, hippocampus.
Coronal, literally, pertaining to a
crown; transverse.
Coronary, encircling.
Coronoid, like a crooked beak.
Corpora albicantia (brain), corpora
Corpus (of long bone), shaft.
Corpus adiposum buccae, buccal pad.
Corpus arantii, nodule (aortic and
pulmonary valves).
Corpus cavernosum penis, corpus
Corpus cavernosum urethrae, corpus
Corrugator, a wrinkler.
Cortex, the bark or outer covering.
Costal, pertaining to a rib.
Cotyloid, cup-like.
Cowper’s gland, bulbo-urethral gland.
Coxa, the hip.
Cranium, the skull.
Crassum, thick, dense, or bulky.
Cremaster, a suspender.
Cribriform, sieve-like.
Cribrosa, perforated with sieve-like
Cricoid, like a ring.
Crista tuberculi majoris, lateral lip
of bicipital groove.
Crista tuberculi minoris, medial lip
of bicipital groove.
Crucial, pertaining to, or shaped like,
a cross.
Crural, pertaining to the leg.
Crural canal, femoral canal.
Crural ring, femoral ring.
Crural septum, femoral septum.
Crus, cerebral peduncle.
Crusta, basis pedunculi.
Cryptorchismus, concealment of the
Cryptozygous, hidden arches.
Cubitum, the elbow.
Cucullaris, pertaining to a cowl or
Culmen, the top or summit.
Cuneate, wedge-shaped.
Cuneiform bone (hand), triquetrum.
Cuneus, a wedge.
Cupola, a dome.
Cymba, a boat or skiff.
Cystic, pertaining to the gall-bladder.
The condition of a thin-walled
swelling containing fluid or semifluid.
Cytoplasm, formative yolk; protoplasm in a cell.
Dacryon, a tear.
Dartos, skinned or flayed.
Deciduous, falling away.
Decussation of lemnisci (fillet), sensory decussation.
Deferens, carrying away.
Deiters, nucleus of, lateral vestibular
Dens, odontoid process.
Dens serotinus, wisdom tooth.
Dentate fascia, dentate gyrus.
Descemet’s membrane, posterior elastic lamina of cornea.
Detrusor, from detrudo, I drive away.
Deutoplasm, literally, wet plasm;
nutritive yolk.
Dia-, through or between.
Diaphragm, a partition.
Diaphysis grow between ’), the
shaft of a bone, or the part which
grows between the epiphyses.
Diarthrosis, an ‘ apart ’ joint— i.e.,
a ‘ free ’ joint (the articular surfaces being free to play upon each
other); synovial joint.
Diencephalon, the ’tween-brain or
inter-brain; thalamencephalon.
Digastric, having two bellies.
Diploe, a doubling.
Discus proligerus, cumulus ovaricus.
Diverticulum, from diverto, ‘ I separate/ or ‘ part/ or ‘ go a different
Dolichocephalic, long-headed.
Dorsal, pertaining to the back
Dorsum, the back.
Douglas, pouch of, recto-uterine or
recto-vaginal pouch.
Douglas, semilunar fold of, arcuate
Duct, nasal, naso-lacrimal duct.
Ductus deferens, vas deferens.
Ductus perilymphaticus, aqueduct of
Duodenum, twelve (probably fingerbreadths) .
Ebur, -oris, ivory.
Eburnea, pertaining to ivory.
Ectopia, a displacement.
Efferent, carrying out.
Embolif ormis, beak-shaped or wedgeshaped.
Emissary, sent out.
Emulgent, milking, straining out.
Enarthrosis, ball-and-socket joint.
Encephalon, the contents of the head
or skull.
Endocardium, ‘ within the heart ’;
the lining membrane of the cardiac
Endognathion, literally, inner jaw.
Endosteum, ‘ within a bone ’; the
medullary membrane.
Ensiform, sword-like.
Ensiform process, xiphoid process.
Entomion, a notch.
Ependyma, from Greek words meaning ' clothing upon/
Ephippium, a saddle.
Epi-, upon or over, above.
Epicardium, upon the heart.
Epididymis, upon the testicle.
Epiglottis, cushion of, tubercle of
Epiotic, upon or over the ear.
Epiphysis (‘ grow upon ’); a process
of a bone which has a secondary
centre of ossification.
Epiploon, from a Greek verb meaning
‘ to float upon/
Epipteric, upon a wing.
Epipteric bone, sutural bone at
Epistropheus, axis.
Epoophoron, above the egg-bearing
Erythroblast, red (cell) germ.
Ethmoid, like a strainer.
Eustachian cushion, tubal elevation.
Eustachian spine (of medial pterygoid plate), processus tubarius.
Eustachian tube, pharyngo-tympanic
Eustachian valve, valve of inferior
vena cava.
Exognathion, literally, outer jaw.
Exomphalos, out of the navel.
Facet (French, facette, a little face),
a small plane surface, usually
Falciform, sickle-like.
Fallopian tube, uterine tube.
Falx, a sickle.
Falx aponeurotica inguinalis, conjoint tendon.
Fascia, a bandage, or a bundle of
Fascia bulbi, fascial sheath of eyeball.
Fascia, Camper’s, superficial layer of
superficial fascia of anterior abdominal wall.
Fascia, Colies’, deep layer of superficial fascia of perineum.
Fascia, coraco-clavicular, clavi-pec
toral fascia.
Fascia infundibular, internal spermatic fascia.
Fascia intercolumnar, external spermatic fascia.
Fascia, Scarpa’s, deep layer of superficial fascia of anterior abdominal
Fascia, Sibson’s, suprapleural membrane.
Fasciculus, a small bundle.
Fasciola cinerea, splenial gyrus.
Fastigium, a roof.
Fauces, the throat.
Fauces, anterior pillar, glosso-palatine arch.
Fauces, posterior pillar, pharyngopalatine arch.
Fel, the gall-bladder.
Femur, the thigh.
Fenestra, an opening, a window.
Fenestra ovalis, fenestra vestibuli.
Fenestra rotunda, fenestra cochleae.
Ferruginea, pertaining to iron-rust.
Fibula, a buckle, clasp, or brace.
Fillet, lemniscus.
Filum, a thread.
Fimbria, a fringe.
Fimbriatum, fringed.
Fissure, a cleft or slit.
Fistula, .a pipe or tube.
Flechsig, tract of, posterior spinocerebellar tract.
Flocculus, a little lock of wool.
Fold, bloodless (Treves), ileo-caecal
Fold, ileo-colic, vascular fold of
Fold, recto-vesical, sacro-genital fold.
Follicle, a small bag or sac.
Fontana, spaces of, spaces of iridocorneal angle.
Fontanelle, a small spring.
Foramen, an aperture or a hole.
Forceps, a claw of a beetle.
Fornicatus, pertaining to an arch.
Fornix, an arch or a vault.
Fossa, a ditch or trench.
Fossa, antecubital, cubital.
Fossa ovalis, saphenous opening.
Fossa, rhomboid, floor of fourth
Fossa, spheno-maxillary, pterygopalatine fossa.
Fourchette, a fork.
Fovea, a small pit.
Foveola, a very small pit.
Frenulum, a small bridle.
Frenum, a bridle.
Frontal, pertaining to the forehead.
Frontal spine (of frontal), nasal spine.
Fundiform, sling-like.
Funicular, pertaining to a cord.
Funiculus, a slender rope, a cord.
Furcalis, pertaining to a two-pronged
Furcula, a small two-pronged fork.
Fusca, dark or dusky.
Galactophorous, milk-carrying.
Galea, a helmet.
Galea aponeurotica, epicranial aponeurosis.
Galen, great vein of, great cerebral
Galen, veins of, internal cerebral
Gallinaginis, of a woodcock.
Gallus, a cock.
Ganglion, a swelling or excrescence.
Ganglion, aortico-renal, lower part
of coeliac ganglion.
Ganglion, Gasserian, trigeminal ganglion.
Ganglion, jugular (O.T.), superior
ganglion of ninth.
Ganglion, jugular (B.N.A.), superior
ganglion of tenth.
Ganglion, lenticular, ciliary ganglion.
Ganglion, Meckel’s, spheno-palatine
Ganglion nodosum (B.N.A.), inferior ganglion of tenth.
Ganglion, ophthalmic, ciliary ganglion.
Ganglion, petrous (O.T. and B.N.A.),
inferior ganglion of ninth.
Ganglion, semilunar, trigeminal ganglion.
Ganglion, stellate, first thoracic
Ganglion, submaxillary, submandibular ganglion.
Gartner’s duct, duct of epoophoron.
Gastric, pertaining to the stomach.
Gastrocnemius, the belly of the
Gemellus, paired or double.
Geminus, twin or twofold.
Geniculate, knee-like.
Genio-, pertaining to the chin.
Gennari, stria of, visual stria.
Genu, the knee.
Gerota’s capsule, renal fascia.
Giacomini, banderella or frenulum,
tail of dentate gyrus.
Gimbernat’s ligament, pectineal part
of inguinal ligament.
Ginglymus, a hinge.
Ginglymus, hinge-joint.
Giraldes, organ of, paradidymis.
Glabella, without hair; smooth.
Gladiolus, a small sword.
Gladiolus, body of sternum.
Gland, Bartholin’s, greater vestibular
Gland, Cowper’s, bulbo-urethral
Glenoid, like a shallow socket.
Glisson’s capsule, hepato-biliary capsule.
Globosus, round or spherical.
Globus, a globe or sphere.
Glomerulus, a small ball of thread.
Glosso-, pertaining to the tongue.
Glottis, the mouthpiece of a flute.
Gluteal, pertaining to the buttock.
Gnathic, pertaining to the jaw.
Gnathion, the jaw.
Gomphosis, a bolting together.
Gonion, an angle.
Gracilis, slender.
Grisea, grey.
Gubernaculum, a rudder.
Gula, the gullet.
Gustatory, pertaining to taste.
Guttural, pertaining to the throat.
Gyrus, a circle; a crook.
Habenula, a small thong or rein.
Hsemorrhoidal, associated with
Hallux, the great toe.
Ham, a thing bent or crooked.
Hamular, hook-shaped.
Harmonia, a fitting together.
Hartmann’s pouch, sacculation at
junction of neck and body of gallbladder.
Hassall, corpuscles of (thymus), concentric corpuscles.
Haustrum, a machine for drawing
Heister’s valves, spiral valve.
Helicine, spiral.
Helicotrema, hole of a spiral.
Helix, a coil or spiral.
Hepar, the liver.
Hepatic, pertaining to the liver.
Hernia, a sprout; a rupture.
Hesselbach’s triangle, inguinal triangle.
Hiatus, a gap.
Hiatus Fallopii, hiatus for superficial
petrosal nerve.
Highmore, antrum of, maxillary
Hilum, a little thing; a trifle.
Hippocampus, a seahorse.
Hippocampus major, hippocampus.
Hippocampus minor, calcar avis.
Hircina, pertaining to a goat.
His, bundle of, atrio-ventricular
Homogenesis see Chapter I.
Homologous )
Houston’s valves, horizontal folds of
Huguier, canal of, anterior canaliculus for chorda tympani.
Humerus, the upper part of the arm;
the shoulder.
Hunter’s canal, subsartorial canal.
Hyaline, glassv.
Hyaloid, like glass.
Hydatid, a watery vesicle.
Hydrocele, a watery tumour.
Hymen, the marriage deity.
Hyoid, like the Greek letter upsilon.
Hypo-, beneath or under.
Hypophysis, ‘ grow beneath.’
Hypothenar, beneath the palm of the
Ileum, implying twists or coils.
Ilium, literally of the soft parts—
i.e., of the flank; os ilium, the bone
of the flank.
Ima, lowest.
Impar, dissimilar (in number), unequal.
Incisivus, cutting into.
Incisura jugularis, suprasternal notch.
Incisura scapularis, suprascapular
Incisura semilunaris (ulna), trochlear
Infundibuliform, funnel-shaped.
Infundibulum, a funnel.
Inguinal, pertaining to the groin.
Inion, literally, the occiput.
Innominatum, unnamed.
Insula, an island.
Intercalary, inserted.
Internodium, the space between two
knots or joints.
Interparietal bone, membranous part
of occipital as a separate bone.
Interpositum, placed between.
Interstitial, belonging to interstices
or small parts between the main
parts of bodies.
Intertubercular sulcus, bicipital
Intumescentia, enlargement (spinal
Iris, the rainbow.
Ischiatic, pertaining to the hip.
Ischium, the hip.
Isthmus, faucium, oro-pharyngeal
Isthmus rhombencephali, upper constricted end of fourth ventricle.
Iter, a passage or road.
Jacobson, cartilage of, sub-vomerine
Jacobson, organ of, vomero-nasal
Jacobson’s nerve, tympanic nerve.
Jejunum, empty or hungry.
Jugal, yolking.
Jugular, pertaining to the throat.
Jugular notch (B.N.A.), suprasternal
Jugum, a yolk.
Kerckring, ossicle, occasional centre
in posterior margin of foramen
Key and Retzius, foramina of
(Luschka), lateral apertures of
fourth ventricle.
Kobelt’s tubes, epoophoron.
Labbe, vein of, inferior anastomotic
vein (connects superficial middle
cerebral with transverse sinus).
Labrum, a basin.
Lacertus fibrosus, bicipital aponeurosis.
Laciniosum, full of folds, indented,
Lacrimal, pertaining to tears.
Lacteal, pertaining to milk.
Lactiferous, milk-carrying.
Lacuna, a hollow or cavity.
Lacunee (of sagittal sinus), lacunae
Lacunar, pertaining to a hollow or
Lacunar ligament, pectineal part of
inguinal ligament.
Lamella, a small plate.
Lamina, a plate.
Lamina cinerea, lamina terminalis.
Lamina cribrosa, medial boundary
of internal auditory meatus.
Lamina papyracea, orbital plate of
Lamina quadrigemina, tectum.
Lateral, on the side of. Used in
reference to the sagittal plane of
the body.
Lateral mass (ethmoid), labyrinth.
Lateral sinus, transverse sinus.
Latissimus, broadest.
Latum, broad.
Lemniscus, a ribbon.
Leptorhine, having small narrow
Levator, a lifter or raiser.
Lien, the spleen.
Lieno-, pertaining to the spleen.
Ligament, a band or bandage.
Ligula, a little tongue.
Limbic lobe, gyrus fornicatus.
Limbous, pertaining to a border.
Limbus, a border.
Limbus fossae ovalis (or limbus
ovalis), annulus ovalis.
Limen, a threshold.
Linea, a line.
Lines, oblique (tibia), soleal line.
Lines, oblique internal (jaw), mylohyoid line.
Lines (occiput), nuchal lines.
Lines, popliteal, soleal line.
Lingual, pertaining to the tongue.
Lingula, a little tongue.
Lister’s tubercle, dorsal tubercle of
Longissimus, longest.
Longitudinal sinus, sagittal sinus.
Lower, tubercle of, intervenous
tubercle (heart).
Lumbar, pertaining to the loin.
Lumbricalis, like an earth-worm.
Lunar, pertaining to the moon.
Lunula, a little moon; a crescent.
Luteum, of a yellow colour.
Luys’ nucleus, subthalamic body.
Lymphatic, from lympha, pure or
spring water; lymph.
Lyra, a lyre; hippocampal commissure.
McBurney’s point (base of appendix),
junction of lower and middle
thirds of spino-umbilical line.
Macula, a spot.
Magendie, foramen, median aperture
of fourth ventricle.
Magnum, os, capitate bone.
Malar, pertaining to the cheek.
Malar bone, zygomatic bone.
Malleolus, a small hammer or mallet.
Malleus, a hammer or mallet.
Mamma, a breast or pap.
Mammilla, a little breast or pap.
Properly spelt mamilla.
Mandible, the chewing bone— i.e.,
lower jaw.
Manubrium, a handle or hilt.
Marshall, oblique vein, oblique vein
of left atrium.
Massa intermedia, interthalamic
Masseter, the chewing muscle.
Mastoid, breast- or pap-like (nipplelike).
Maxilla, jaw.
Meatus (pi. Meatfis), a passage or
Meckel’s cave, cavum trigeminale.
Meckel’s diverticulum, diverticulum
Mediastinum, standing in the middle;
a partition.
Medulla, marrow.
Megacephalic, having a large head.
Megaseme, having a large index.
Meibomian glands, tarsal glands.
Meissner’s plexus, plexus of the submucosa.
Membrane, costo-coracoid, clavi
pectoral fascia.
Meninges, membranes.
Meniscus, a crescent.
Meniscus (knee), semilunar cartilage.
Mental, pertaining to the chin.
Mesaticephalic, having a head with
an index of mean value.
Mesencephalon, the mid-brain.
Mesentery, in the middle of, or
among, the intestines.
Mesial, nearer to the sagittal plane
of the body.
Meso-, in the midst of. In compounds usually implies a structure
like a mesentery, a peritoneal attachment fold.
Mesocephalic, pertaining to a head
of mean capacity.
Mesogastrium=meso- (q.v.) and
Mesognathion, middle jaw.
Mesometrium=meso- [q-v.) and
Mesonephros, mid-kidney.
Mesorhine, pertaining to an intermediate nasal index; a condition
intermediate between broad-nosed
and narrow-nosed.
Mesosalpinx =meso- (q.v.) and tube.
Mesoseme, intermediate index.
Meta-, after or beyond.
Meta-nephros, hind-kidney.
Metencephalon, the after-brain.
Metopic, pertaining to the forehead.
Metopism, persistence of the metopic
or frontal suture.
Microcephalic, pertaining to a small
Microseme, small index.
Middle commissure, interthalamic
Millimetre (mm.), slightly less than
2V of an English inch.
Minimae, least, smallest.
Mitral, resembling an Asiatic headdress, or mitre.
Modiolus, the nave of a wheel.
Molar, pertaining to a mill, or to
Monro, foramen, interventricular
Mons veneris, mons pubis.
Montanum, pertaining to a mountain.
Monticulus, a small mountain.
Morbus, a disease.
Muliebris, pertaining to a woman,
Miillerian duct, para-mesonephric
Multangulum majus, os, trapezium.
Multifidus, many cleft; divided into
many parts.
Musculo-spiral nerve, radial nerve.
Myelencephalon, marrow-brain.
Myeloplaxes, marrow-plates.
Myentericus, pertaining to the muscular tissue of the bowel.
Mylo-, pertaining to a mill.
Myocardium, the muscular tissue of
the heart.
Myrtiform, like a myrtle-berry.
Nares, posterior, posterior apertures
of nose.
Naris (pi. nares), a nostril.
Nasal, pertaining to the nose.
Natal, pertaining to the buttock.
Natis (pi. nates), the buttock.
Navicular, pertaining to a boat.
Nephros, a kidney.
Neural, pertaining to a nerve.
Neuroglia, literally ‘ nerve glue.’
Nictitans, winking.
Norma, a rule or measure (aspect).
Notochord, string or cord of the back.
Nucha, the nape of the neck.
Nuck, canal, vaginal process.
Nucleus, a kernel.
Nuhn, glands, anterior lingual (seromucous) glands.
Nymphae, nymphs or goddesses of
the fountains, woods, trees, etc.;
labia minora.
Obelion, a horizontal line (perhaps
a little spit).
Obex, a bolt; a barrier.
Obturator, one who closes or stops
Occipital, pertaining to the back
part of the head.
Odontoblast, a tooth-germ.
Odontoid, tooth-like.
Odoriferae, carrying odours.
(Esophagus, food-carrier.
Olecranon, head or point of the
Olfactory, pertaining to smell.
Olfactory trigone, olfactory pyramid.
Olivary, pertaining to an olive.
Omentum, that which is drawn over.
Omentum, gastro - hepatic, lesser
Omentum, gastro-splenic, gastrosplenic ligament.
Omo-, pertaining to the shoulder.
Omphalo-, pertaining to the navel.
Operculum, a cover or lid.
Ophryon, the eyebrow.
Ophthalmic, pertaining to the eye.
Opisthion, hinder or rear.
Opisthotic, behind the ear.
Optic, pertaining to sight.
Optic thalamus, thalamus.
Ora, a border or margin.
Orthognathous pertaining to a
straight (non-projecting) jaw.
Os incae, interparietal bone.
Os japonicum, bi-partite zygomatic
Os magnum, capitate bone.
Os, oris, a mouth.
Os, ossis, a bone.
Os tincae, external os of uterus.
Ossicle of Kerckring, occasional
centre in posterior margin of
foramen magnum.
Osteoblast, bone-germ.
Osteoclast, bone-destroyer.
Osteogenetic, bone-forming.
Ostium, a door, entrance, or exit.
Otic, pertaining to the ear.
Otoconia, ear-dust.
Otoliths, ear-stones.
Ovary, egg-forming organ.
Oxyntic, producing acid.
Pacchionian bodies, arachnoid granulations.
Pacinian corpuscles, lamellated corpuscles.
Palatum, the palate.
Pallium, a covering.
Palmar, pertaining to the palm.
Palpebra, an eyelid.
Pampiniform, tendril-like.
Pancreas, literally, all or completely
Para-, near, by the side of.
Paradidymis, near the testis.
Parametrium, near the womb.
Parietal, pertaining to a wall.
Paroophoron, near the egg-bearing
organ; medial mesonephric tubules.
Parbtid, near the ear.
Parovarium, epoophoron.
Pars intermedia (Wrisberg), sensory
root of facial nerve.
Patella, a small dish; a plate.
Pecten, another name for the os
pubis; a comb.
Pectinatus, pertaining to a comb.
Pectineal or Pectineus, associated
with the pecten bone or os pubis.
Pectiniform, comb-like.
Pectoralis, pertaining to the breast.
Peduncle of corpus callosum, paraterminal gyrus.
Pelvis, a basin.
Penicillus, a painter’s brush or pencil.
Penis, a tail, or pendant process.
Peri-, around, about, or near.
Pericardium, around the heart.
Perineum, from a Greek verb meaning ‘ I dwell, or am situated,
Perineum, central point of, perineal
Periosteum, around bone.
Periotic, around the ear.
Peritoneum, from a Greek word
meaning ‘ stretched around/
Peroneal or Peroneus, ‘ pertaining
to the peronee/ the Greek name for
Petit’s canal, zonular spaces.
Petit’s triangle, lumbar triangle.
Petrous, rocky.
Phalanx, a rank of soldiers.
Pharynx, the throat.
Phenozygous, having visible arches.
Philtrum, a love potion.
Phrenic, pertaining to the diaphragm.
Pineal, belonging to, or like, a pinenut or pine-cone.
Pinna, a kind of shell-fish; a feather
or wing.
Pisiform, like a pea.
Pituitary, pertaining to phlegm or
mucus; hypophysis.
Placenta, a flat cake.
Plagiocephalous, pertaining to an
oblique or twisted head.
Planta, the sole of the foot.
Plantar, pertaining to the sole of the
Platycnemism, broadness of leg.
Platyrhine, having a broad nose.
Platysma, a broad sheet.
Pleura, a rib.
Plexus, a twining or network.
Plexus, Auerbach’s, myenteric plexus.
Plexus, gulae, cesophageal plexus.
Plexus, Meissner’s, plexus of the
Plica, a fold.
Plica hypogastrica, lateral umbilical
Plica urachi, median umbilical fold.
Plicae palmatae (uterus), arbor vitae.
Pneumogastric, pertaining to the
breathing organs and stomach.
Pocularis, pertaining to a cup.
Pollex, the thumb.
Pomum Adami, laryngeal prominence.
Pons, a bridge.
Popliteal or Popliteus, pertaining to
the ham.
Porta, a gate.
Portal, pertaining to a gate.
Portio major and minor, sensory and
motor roots of trigeminal nerve.
Postaxiah r , , T
Preaxial / see Cha P ter L
Posterior vesicular column (Clarke),
thoracic (or dorsal) nucleus.
Posticus, posterior.
Poupart’s ligament, inguinal liga
Primary divisions (of spinal nerves),
anterior and posterior rami.
Proctodaeum, the threshold of the
Prognathous, having a projecting
lower jaw.
Proligerus, bearing offspring; germinating.
Pro-nephros, fore-kidney.
Pro-otic, before the ear.
Prosencephalon, the fore-brain.
Prostate, standing before; or, more
probably, pertaining to a porch
or vestibule.
Psalterium, a psaltery or instrument
of the lute kind.
Psalterium (lyra), hippocampal commissure.
Psoas, from a Greek word meaning
* the muscles of the loins,’ and
secondarily ‘ the loins themselves.’
Pterion, a wing.
Pterotic, pertaining to a wing.
Pterygoid, wing-like.
Pubes, the hair which appears on the
external genital organs at the age
of puberty.
Pubic, pertaining to the os pubis.
Pudendal, pertaining to the pudendum.
Pudendum, ‘ of which one ought to
be ashamed.’
Pudic, modest or chaste.
Pulmo, a lung.
Pulmonary, belonging to the lungs.
Pulvinar, a couch or cushion,
Putamen, trimmings or clippings.
Pyloric vestibule, pyloric antrum.
Pylorus, literally, a gate-keeper.
Pyriformis, pear-shaped.
Quadratus, square.
Quadriceps, having four heads.
Quadrigeminus, fourfold, four.
Racemose, pertaining to a cluster of
grapes; full of clusters; clustering.
Radius, a staff or rod; the spoke of
a wheel.
Ramus, a branch.
Ranine, pertaining to a frog.
Raphe, a seam.
Receptaculum, a receptacle.
Receptaculum chyli, cisterna chyli.
Rectus, straight.
Recurrent, running back.
Refractory, breaking up.
Reil, island of, insula.
Ren, a kidney.
Restiform, like a rope or cord.
Restiform body, inferior cerebellar
Rete, a net.
Retina, from rete, a net.
Retrahens, drawing back.
Retzius, cave, retro-pubic space.
Revehens, carrying back.
Rhinencephalon, the ‘ nose ’ or olfactory brain.
Rhinion, a nose.
Rhombencephalon, the rhomb-brain
Rhomboid ligament, costoclavicular
Riedel’s lobe, an elongation of lower
margin of right lobe of liver (due
to pressure).
Rima, a cleft or chink.
Risorius, laughing.
Rivini, ducts, sublingual ducts.
Rolando, fissure, central sulcus.
Rostrum, a beak.
Rotula, a little wheel.
Rugae, wrinkles.
Saccus reuniens, sinus venosus
Sacrum, sacred; derivation and original meaning very doubtful.
Sagittal, pertaining to an arrow;
Salpinx, a trumpet or tube.
Salvatella, saving, or making well.
Santorini, cartilages, corniculate cartilages.
Santorini, duct, accessory pancreatic
Santorini, fissures, clefts in cartilage
of exterior auditory meatus.
Saphenous, apparent, manifest.
Sartorius, pertaining to a tailor.
Scala, a ladder, flight of steps, or
Scala media, duct of cochlea.
Scalenus, of unequal sides.
Scansorius, of, or for, climbing.
Scaphocephalous, having a head like
a boat.
Scaphoid, like a boat.
Scapula, a spade; probably from a
Greek verb meaning ‘ I dig/
Scarpa’s triangle, femoral triangle.
Schlemm, canal, sinus venosus
Schindylesis, a splitting or cleavage.
Sciatic (identical with Ischiatic),
pertaining to the hip.
Sclera, hard.
Sclerotic, hard; sclera.
Scrobiculus, a little ditch or trench.
Scrotum, a skin bag or pouch; a hide
(probably originally ‘ scortum J ).
Sebaceous, pertaining to grease.
Sella, a seat; a saddle.
Semilunar bone, lunate.
Semilunar fold of Douglas, arcuate
Seminalis, pertaining to semen.
Septum, a fence or barrier.
Serotinus, that comes or happens
Serratus, jagged like a saw.
Sesamoid, like sesame (a kind of
Shrapnell’s membrane, flaccid part
of membrana tympani.
Sibson’s fascia, suprapleural membrane.
Sigmoid, like the Greek letter S
Sigmoid cavity, greater, trochlear
Sigmoid cavity, lesser, radial notch.
Sigmoid cavity (of radius), ulnar
Sigmoid notch (mandible), mandibular notch.
Sinus, a cavity or hollow.
Sinus, Valsalva, of, sinuses of aorta.
Smegma, a cleanser.
Solar, relating to the sun.
Solar plexus, coeliac plexus.
Soleus, a sole or sandal; a sole-fish.
Sperma, seed or semen.
Spermatic, pertaining to semen.
Spermatoblast, a seminal bud.
Spermatozoa (plural), seminal
Sphenoid, wedge-like.
Spheno-maxillary fossa, pterygopalatine fossa.
Sphenotic, pertaining to the sphenoid
bone and ear-capsule.
Sphincter, binding or closing tight.
Spigelian lobe, caudate lobe.
Splanchnic, pertaining to viscera.
Splenium, a bandage or compress.
Splenius, pertaining to a bandage.
Squamous, scaly.
Stapes, a stirrup.
Stellatum, starry.
Stensen’s duct, parotid duct.
Stephanion, a crown or wreath.
Sternebra, a segment of the sternum.
Sternum, the breast or chest.
Stomata, mouths or pores.
Stomatodaeum or Stomodaeum, the
threshold of the mouth.
Stria medullaris, stria habenularis.
Striae acusticae, auditory striae.
Striae medullares, auditory striae.
Styloid, pen-like.
Subflava, somewhat yellow.
Subiculum, an under layer or support.
Submaxillary, submandibular.
Substantia gelatinosa (Roland), gelatinous matter.
Sudoriferous, sweat-carrying.
Sulcus, a furrow.
Supercilium, an eyebrow.
Supracallosal gyrus, indusium griseum.
Sural, pertaining to the calf of the
Sustentaculum, a prop or support.
Sustentaculum lienis, phrenico-colic
Suture, a sewing together, a seam.
Sylvius, aqueduct, aqueduct of midbrain.
Symphysis, growth together.
Syn-, with; together with (union or
harmony may be implied).
Synarthrosis, literally, a * together
with ' (direct) joint; fibrous joint.
Synchondrosis, bound together with
cartilage; cartilaginous joint.
Syndesmosis, bound together with
bands or bonds.
Synovia, resemblance to the white
of an egg.
Taenia, a band or ribbon.
Talus, a die (pi. dice); the ankle-bone.
Tapetum, a carpet or coverlet.
Tarsus, a broad flat surface; the
Tectorius, pertaining to a cover.
Tegmen, a covering.
Tegmentum, a covering.
Tela, a web.
Telencephalon, the end-brain.
Temporal, pertaining to the temples
of the head.
Tendo Achillis, tendo calcaneus.
Tendon, from tendo, ‘ I stretch.’
Tenon’s capsule, fascial sheath of
Tentorium, a tent.
Tenuis, slender, small.
Teres, rounded.
Testis, a witness.
Thalamencephalon, the bedchamberbrain, or inter-brain.
Thalamus, a bedchamber; a marriage-bed.
Thebesian valve, valve of coronary
Thebesian veins, venae cordis minimae.
Theca, a cover, case, or sheath.
Thenar, the flat of the hand.
Thorax, the breast or chest; a breastplate.
Thymus, thyme.
Thyroid, like a shield.
Tibia, a pipe or flute; the shin-bone.
Tinea, a small fish, perhaps the tench.
Tonsil, palatine, tonsil.
Tonsil, pharyngeal, naso-pharyngeal
Torcular, a wine-press (twisting is
Torcular Herophili, confluens sinuum.
Torus, a protuberance.
Torus tubarius, tubal elevation.
Trabecula, a little beam.
Trachea (‘ rough ’), the wind-pipe.
Trachelo-, belonging to the neck.
Tragus, a goat.
Trapezium, a table; a four-sided,
figure, no two sides of which are
parallel to one another.
Trefoil, having three leaves.
Treitz, muscle, suspensory muscle of
Treves, bloodless fold of, ileo-csecal
Triangular fascia, reflected part of
inguinal ligament.
Triangular fibro-cartilage, articular
Triangular ligament, inferior or superficial layer; perineal membrane.
Triceps, having three heads.
Trigeminus, threefold, triple.
Trigdnocephalus, a triangular head.
Trigonum, a triangle; triangular.
Triquetrum, three-cornered; triangular.
Triticea, wheaten, or like a grain of
Trochanter, from a Greek verb meaning ‘ I roll, turn, or revolve.'
Trochlea, the wheel of a pulley.
Trochlear, pulley-shaped.
Trochlearthrosis, a pulley-joint.
Trochoides, wheel-like.
Trolard, vein of, superior anastomotic
Tuba, a trumpet.
Tubarius, pertaining to a trumpet.
Tube, auditory, pharyngo-tympanic
Tube, Eustachian, pharyngo-tympanic tube.
Tubercle, a small swelling.
Tubercle, articular, articular eminence.
Tubercle, greater multangular, of,
crest of trapezium.
Tubercle, Lister’s, dorsal tubercle of
Tubercle, Lower, of, intervenous
tubercle (heart).
Tubercle, radial, dorsal tubercle of
Tuberosity, an exaggerated tubercle.
Turbinals or turbinate bones, conchse.
Turbinate, whirled or coiled; like a
Turbo, a whirl or coil; a top.
Turcica, Turkish.
Tympanum, a drum.
Ulna, the elbow, but more usually
the forearm.
Umbilicus, the navel.
Umbo, a boss or knob.
Unciform, hook-like.
Unciform bone, hamate.
Uncinate, furnished with a hook.
Ungual, relating to a nail.
Unguis, a nail.
Unicornis, one-horned.
Urachus, urine-holder.
Ureter, from a Greek verb meaning
‘ I pass urine.'
Urethra, the canal by which urine is
Uriniferous, urine-carrying.
Uterus, the womb or matrix.
Uterus masculinus, prostatic utricle.
Utricle, a little womb or matrix.
Uvea, from uva, a bunch of grapes;
a cluster.
Uvula, a small bunch of grapes.
Vagina, a scabbard or sheath.
Vagus, strolling about, wandering,
Valgus, bow-legged.
Vallecula, a little valley.
Vallecula Sylvii, vallecula cerebri.
Vallum, a rampart.
Valsalva, sinuses, sinuses of aorta.
Valve, bicuspid, left atrio-ventricular
Valve, Eustachian, valve of inferior
vena cava.
Valve, ileo-caecal, ileo-colic valve.
Valve, mitral, left atrio-ventricular
Valve, Thebesian, valve of coronary
Valve, tricuspid, right atrio-ventricular valve (cusps are anterior
inferior medial).
Valve, Vieussens, superior medullary
Varus, bent or turned inwards.
Vas (pi. vasa), a vessel.
Velum, a curtain or veil.
Velum interpositum, tela choroidea.
Velum palatinum, soft palate.
Veneris, ' of Venus.’
Ventral, pertaining to the belly.
Ventricle of larynx, sinus of larynx.
Vermiform, like a worm.
Vertebra, primarily means a joint,
but more particularly a joint of
the spine.
Vertex, the top or crown of the head.
Veru, a dart, javelin, or spear.
Verumontanum, urethral crest.
Vesalii, foramen, emissary sphenoidal
Vesica, the urinary bladder.
Vesical, pertaining to the urinary
Vespertilio, a bat.
Vestibular nucleus, principal or
dorsal; medial nucleus.
Vestigial, pertaining to a trace.
Vestigium, a trace or vestige.
Vibrissa, a stiff hair of the nostril.
Vicq d’Azyr, bundle of, mamillothalamic tract.
Vidian canal, pterygoid canal.
Vidian nerve, nerve of pterygoid
Vieussens, ansa of, ansa subclavia.
Vieussens, valve, superior medullary
Villus, shaggy hair; a tuft of hair.
Vinculum, a band or bond.
Vitelline, pertaining to the yolk of
an egg.
Vitellus, the yolk of an egg.
Vitreous, like glass, glassy.
Vola, the palm of the hand.
Volar, pertaining to the palm; palmar, or anterior.
Vomer, a ploughshare.
I 7 I 3
Vorticosse, full of whirlpools, eddying, coiled.
Vulva, a wrapper or covering.
Wharton’s duct, submandibular
Willis, circle of, circulus arteriosus.
Winslow, foramen, opening of lesser
Winslow, ligament, oblique posterior
ligament of knee.
Wirsung, duct, pancreatic duct.
Wolffian duct, mesonephric duct.
Wood’s muscle, abductor metatarsi
Wormian bones, sutural bones.
Wrisberg, cartilage, cuneiform cartilage.
Wrisberg, ligament, accessory attachment of lateral semilunar cartilage.
Wrisberg, nerve, medial cutaneous
nerve of arm.
Xiphoid, like a sword.
Y-shaped ligament of Bigelow, iliofemoral ligament.
Zinn, inferior tendon or ligament
(eye), lower part of common tendinous ring.
Zinn, zonule, ciliary zonule.
Zygoma, a yoke.
Arteries, nerves, ligaments, joints, muscles, and veins are classified under corresponding
headings. Where a number is given in heavy type, the principal reference is indicated.
Abapical pole of ovum, 25
Abdomen, 674, 754
division into regions, 755
Abdominal cavity, 756
pregnancy, 19
wall, 704
landmarks of, 704
Abducent nerve, 1166, 1447, 1616
in orbit, 1254
Abductor digiti minimi (foot), 646
(hand), 496
hallucis, 644
ossis metatarsi quinti, 643
pollicis brevis, 493
longus, 505
Abernethy, fascia of, 854
Aberrant ductules, 751
Abnormal definition, 5
Accessory bile-ducts, 779
nerve. See Cranial nerves
obturator nerve, 580, 847
process, 140
Acervulus cerebri, 1590
Acetabulum, 340
ossification of, 341
Acrocephaly, 270
Acromial anastomosis, 443
Acromion, 296 , 298
Acromio-clavicular joint, 444
Acromio-thoracic artery, 426
Adamantoblasts, 287
Addison's lines, 755
Adductor brevis, 577
hallucis, 649
longus, 576
magnus, 577
minimus, 578
pollicis, 494, 496
Adenoids, 1373
Agger nasi, 214
Aggregated nodules, 868
Air-cells, mastoid, i88
sphenoidal, 199
Akinesis, 9
Ala cinerea, 1490
of frontal bone, 181
orbitalis, 273
of sacrum, 148
temporalis, 275
Alae of ethmoid, 207
of vomer, 228
Alar thoracic artery, 427
Alimentary canal (embryonic), 23
Allantoic diverticulum, 31
Allantois, 31, 32, 33, 954
Alveolar arches, 1337
index, 269
point, 244, 268
process of maxilla, 214
Alveoli, pulmonary, 1028
Alveus, 1525, 1569
Ambiguus nucleus, 1625 , 1626, 1627
Ameloblasts, 287
Amitosis, 9, 12
Amnion, 27, 30, 32, 106
Amniotic cavity, 25, 26, 32
duct, 32
fluid, 106
folds, 31, 32
Amphioxus gastrulation, 35
mesoderm, 36
Ampulla of duodenum, 865
of ear, 1684
of rectum, 944
of vas deferens, 935
Amygdaloid nucleus, 1524, 1532
tubercle, 1524
Anal canal, development of, 965
of female, 978
lymphatics of, 964
of male, 945
structure of, 961
columns, 961
fascia, 922
membrane, 965
valves, 962
Analogy, 122
Anaphase, 10
Anastomosis, acromial, 443
cruciate, 538, 585 , 587
round, elbow-joint, 479
knee-joint, 548
scapular, 441
trochanteric, 585
Anatomical description, 2
snuff-box, 484
textbooks, 2
Anatomy, 1
Anconeus muscle, 500
Angle, cranio-facial, 260
of eye, 1289
of mandible, 232
pubic, 339, 552
sacro-vertebral, 151
sternal, 102, 1013
subcostal, 165
subpubic, 344
Angles of pharyngeal lateral pouches. 70,76
Angular process, medial, 181
Animal cell, 8
Ankle-joint, 661
Annular-ligament of radius, 520
Annulus fibrosus—
of intervertebral disc, 1107
of tympanic membrane, 1676
ovalis, 1055
Ano-coccygeal body, 675
Ansa hypoglossi, 1206
lenticularis, 1531, 1539 , 1567
peduncularis, 1565, 1567
subclavia, 1239, 1335
Antecubital lymphatic glands, 452, 514
Antihelix, 1295
Antinion, 268
Antitragicus muscle, 1296
Antrum, definition, 115
pyloric, 760
tympanic, 188, 1681
Anus, 674
development of, 965
imperforate, 965
lymphatics of, 964
Aorta, abdominal, 825
branches of, 825
guides to bifurcation of, 708
arch of, 1037
development of, 1041
ascending, 1033
branches of, 1036
development of, 1037
great sinus of, 1036
descending, 1089
development of, 1094
embryonic, 51, 68
thoracic, 1033
varieties of, 1040
Aortic arches, 68, 91, 1118
isthmus, 1038
lymphatic glands, 832
nodule, 1063
orifice, 1062
position of, 1064
plexus, 811
sinuses, 1063
spindle, 1038
valve, 1062
vestibule, 1060
Aortico-renal ganglion, 809
Aperture, bony, of nose, anterior, 244
posterior, 251
median, of fourth ventricle, 1492, 1608
Apex of lung, 1021
Apical pole of ovum, 25
Aponeurosis, bicipital, 453
epicranial, 1156
palatine, 1351
palmar, 484
plantar, 642
Apophysis, 114
Appendices epiploicae, 768, 871
Appendix, vermiform, 764
development of, 63, 872, 883
mesentery of, 764, 787 , 884
Aquatic respiration, 1377
Aqueduct of mid-brain, 1488, 1560
development of, 58, 1561, 1589
of vestibule, 191, 264
Aqueductus cochleae, 193, 1165, 1686
Aqueous humour, 1661
Arachnoid granulations, 1599, 1609
membrane, cranial, 1608
spinal, 1413
Arbor vitae cerebelli, 1485
of uterus, 977
Arc, longitudinal, of skull, 269
Arch, coraco-acromial, 445
crico-thyroid, 1215
femoral, deep, 719, 734
jugular, 1175
nasal, 1154
palato-glossal, 1350
palato-pharyngeal, 1350
palmar, deep, 484, 497 , 499
superficial, 483, 487, 498
plantar, 614, 657
subpubic, 344
superciliary, 181
Archenteric cavity, 25
Archenteron, 27, 30
Arches, arterial, 1118
dental, 281
of foot, 672
visceral, 66, 278
metamorphosis of, 1376
Archoplasm, 9
Arcuate eminence, 189, 263, 1684
fibres of medulla, 1465
ligaments of knee-joint, 631
of diaphragm, 836
line, 727
Arcus parieto-occipitalis, 1501
tendineus, 947
Area, bucco-pharyngeal, 34
cochlear, 190
embryonic, 33
orbital, 1493
proto-cardiac, 34
tentorial, 1493
vestibular, 1491
Areas of Broca, 1446
of cortex, 1569
of Flechsig, 1467
vestibular, superior and inferior, 190
Areola of nipple, 414
Arm, landmarks of, 446
Arteria, centralis retinae, 1260
rectae, 906
thyroidea ima, 1038, 1204, 1221
Artery or arteries—
acromio-thoracic, 426
alar thoracic, 427
anastomosis, cruciate, 538, 585 , 87
round, elbow-joint, 479
knee-joint, 548
scapular, 441
aorta, abdominal, 825
branches of, 825
development of, 1041, 1118
guides to bifurcation, 708
arch of, 1037
development of, 1041
ascending, 1033
branches of, 1036
development of, 1037
great sinus of, 1036
descending, 1089
development of, 1094
embryonic, 51, 68
primitive dorsal, 1118
ventral, 1118
thoracic, 1033
varieties of, 1040
aortic arches (emb.), 68, 91
appendicular, 797
arch, crico-thyroid, 1215
palmar, deep, 484, 497 , 499
superficial, 483, 487, 498
plantar, 614, 657
arcuate, 612
ascending pharyngeal, 1219
auditory, internal, 1448, 1576
of auricle, 1672
auricular, deep, 1305
posterior, 1161, 1219
axillary, 425
varieties of, 428
azygos, of vaginal, 980
basilar, 1447, 1575
brachial, 454
collateral circulation after ligature, 457
profunda, 455
varieties of, 456
bronchial, 1090, 1029
buccal, 1282, 1307
of bulb, female, 703
male, 688
bulbar, of vertebral, 1575
caecal, 797
calcaneal, lateral, of peroneal, 626
medial, of post-tibial, 627
calcarine, 1577
capsular, of liver, 885
carotid, common, 1207
left, in thorax, 1039
ligation of, 1210
surgical compression, 1210
internal, 1323
at base of brain, 1449
cavernous part of, 1169
cerebral part of, 1570
development of, 91, 1118,
1122, 1324
Artery or arteries ( continued )—
carotid, internal, petrous part of, 1399
carpal, anterior, of radial, 475
of ulnar, 479
arch, posterior, 478, 508, 511
posterior, of radial, 511
of ulnar, 478
rete, anterior, 478, 479, 498
centralis, retinae, 1260, 1658
cerebellar, anterior inferior, 1448, 1576
posterior inferior, 1575
superior, 1448, 1576
cerebral, anterior, 1449, 1572
middle, 1449, 1573
posterior, 1448, 1576
cerebral areas of, 1577
cervical, ascending, 1242
deep, 1148, 1244
transverse, 1193, 1243
deep branch of, 402, 1192,
superficial branch of, 1142,
of uterine, 980
choroidal, anterior, 1449, 1571
posterior, 1577
ciliary, anterior, 1260, 1651
long, 1260, 1651
posterior, 1260
short, 1260
circulus arteriosus, 1449, 1577
major, 1651
minor, 1651
circumflex, anterior humeral, 427
fibular, 609
iliac, deep, 732
superficial, 508, 712
lateral femoral, 585, 588
medial femoral, 585, 589
posterior humeral, 427, 428
scapular, 427
clitoris, dorsal artery of, 703
cochlear, 1694
coeliac, 811
colic, left, 801
middle, 797
right, 797
communicating, anterior, 1449, 1573
posterior, 1449, 1571
companion artery of sciatic nerve,
coronary, of heart, 1036
of uterine, 980
of corpus callosum, 1573
cremasteric, 731
crico-thyroid arch, 1215
branch of superior thyroid, 1214
dental, anterior superior, 1308
inferior, 1307
posterior superior, 1307
dorsalis, indicis, 511
linguae, 1216
pedis, 611
varieties of, 614
pollicis, 511
Artery or arteries ( continued )—
epigastric, inferior, 729
branches of, 731
guide to, 708
superficial, 584, 711
superior, 731, 1000
ethmoidal, anterior, 1261, 1281,
posterior, 1261
facial, on face, 1278
in neck, 1217
transverse, 1158, 1281
femoral, 563, 581 » 587
profunda of, 584, 588
fibular, circumflex, 609
of frenulum linguae, 1216
ganglionic, 1449, 1573 , 1577
gastric, left, 812
right, 814
gastro-duodenal, 814
gastro-epiploic, left, 812
right, 814
genicular, of popliteal, 548
gluteal, inferior, 538, 926
superior, 536, 927
helicine, 953
hepatic, 813, 885
varieties of, 815
hyaloid, 1664
ileal, 796
ileo-colic, 787
iliac, circumflex deep, 732
superficial, 712
common, 849
branches of, 851
collateral circulation after
ligature of, 852
guide to, 708
varieties of, 852
external, 853
branches of, 854
collateral circulation after
ligature of, 854
guide to, 708
varieties of branches, 854
internal, 923
branches of, 924
foetal condition of, 923
varieties of, 923
ilio-lumbar, 926
indicis, dorsalis, 511
radialis, 487, 498
infra-hyoid, 1214
infra-orbital, 1282 , 1307
innominate, 1038
varieties of, 1039
intercostal, 997
anterior, 998, 1000
collateral, 1093
lower two, 732, 999
posterior, 998, 1091
superior, 997, 1093, 1243
interlobar, of kidney, 904
interlobular, of kidney, 905
of liver, 885
Artery or arteries ( continued )—
interosseous, anterior, 478
common, 478
posterior, 506, 507
recurrent, 508
of iris, 1651
jejunal, 796
of kidney, 904
labial, inferior, 1279
superior, 1280, 1362
of labyrinth, 1694
lacrimal, 1260
laryngeal, inferior, 1243
superior, 1214
of larynx, 1396
lenticular, 1573
lenticulo-striate, 1573
lenticulo-thalamic, 1573
of ligamentum teres of uterus, 731
lingual, 1215
lumbar, 847
abdominal branches of, 732
branches of, 847
malleolar, lateral anterior, 609
medial anterior, 609
of posterior tibial, 627
mammary, external branches of
lateral thoracic artery, 426
internal, cervical part of, 1242
thoracic part of, 999
branches of, 1000
masseteric, 1307
mastoid of occipital, 1146, 1219
maxillary, 1304
branches of, 1305
median, 478 , 498, 5 1 ^>
meningeal, accessory, 1306, 1600
anterior of ethmoidal, 1599
of ascending pharyngeal, 1220,
of internal carotid, 1600
middle, 1306, 1600
of occipital, 1146, 1219, 1601
of vertebral, 1575, 1601
mental, of facial, 1279
of inferior dental, 1283, 1307
mesenteric inferior, 801
branches of, 801
superior, 796
branches of, 796
metacarpal, dorsal, 511
palmar, 498
metatarsal, dorsal, 613
first plantar, 657
musculo-phrenic, 1000
mylo-hyoid, of inferior dental, 1307
nasal, dorsal, 1261, 1281
lateral, of facial, 1280
nutrient arteries—
of femur, 587
of fibula, 626
of humerus, 455, 456
of radius, 478
of tibia, 626
of ulna, 478
Artery or arteries [continued )—
obturator, 589, 925, 927
abnormal, 566
occipital, first part, 1218
descending branch of, 1218
second and third parts, 1146
olecanon rete, 479
ophthalmic, 1170, 1259
ovarian, 830
in pelvis, 978
of palate, soft, 1354
palatine, ascending, of facial, 1217
of ascending pharyngeal, 1220
greater, 1308 , 1338, 1362
lesser, 1308
palmar arch, deep, 484, 497, 499
superficial, 483, 487, 498
palpebral, lateral, 1260, 1281
medial, 1261, 1281
pancreatica magna, 812
pancreatico-duodenal, inferior, 798
superior, 814
pedis, dorsalis, 611
varieties of, 614
perforating, foot, 613, 657
hand, 498
of profunda femoris, 586
pericardiaco-phrenic, 1000
perineal, superficial, of female, 703
of male, 687
transverse, 687
peroneal, 610, 626
branches of, 626
communicating branch of, 627
varieties, 626
pharyngeal, ascending, 1219
of maxillary, 1308
of pharynx, 1373
phrenic, 827
placental, 51
plantar arch, 655, 657
lateral, 655 , 657
medial, 654 , 657
pollicis, dorsalis, 511
princeps, 487, 497
pontine, 1448, 1575
popliteal, 541, 546
varieties of, 548
princeps pollicis, 487, 497
profunda, of brachial, 455
femoris, 584 , 588
linguae, 1216, 1346
of pterygoid canal, 1308, 1362
pterygoid, of maxillary, 1307
pubic, 731
of obturator, 589
pudendal, accessory, 689
deep external, 584
internal, 925
female, 703
in gluteal region, 539
male, 686
superficial external, 584, 710
pulmonary, 1028, 1042
development of, 1042
Artery or arteries [continued )—
pulmonary, trunk, 1042
development of, 1042
radial, 473
first part, 474
recurrent branch of, 475
second part, 509
third part, 497
varieties of, 475, 498
radialis indicis, 487, 498
rectal, 906
inferior, 963
middle, 925, 963
superior, 802, 963
recurrent, anterior tibial, 609
ulnar, 477
posterior interosseous, 508
tibial, 609
ulnar, 477
radial, 475
renal, 827
aberrant, 828
accessory, 828
varieties, 828
rete, olecranon, 479
retinal, 1658
sacral, lateral, 926
median, 946
saphenous, of descending genicular,
587, 589
of scalp, 1153
scapular, circumflex, 427
of sclera, 1643
septal, of facial, 1280
of spheno-palatine, 1308, 1339,
spheno-palatine, 1308, 1361
spinal, anterior, 1447, 1575
lateral, 1434
posterior, 1434, 1447, 1575
of posterior intercostals, 1093,
splenic, 812
striate, 1573
stylo-mastoid, 1219
subclavian, 1237
development of, 1240
left, first part of, 1240
in thorax, 1040
right, first part of, 1237
second part of, 1240
third part of, 1191
guide to, 1192
subcostal, 732, 848, 1093
sublingual, 1216
submental, 1218
subscapular, 427
suprahyoid, 1216
supra-orbital, 1154, 1260
suprarenal, inferior, 828
middle, 827
superior, of phrenic, 827
suprascapular, 402, 438 , ii 93 ; 1243
suprasternal of suprascapular,
43 8 . 1243
Artery or arteries ( continued )—
supratrochlear (brachial), 456
of ophthalmic, 1154, 1261
sural cutaneous, 548
tarsal, 612
temporal, anterior deep, 1307
middle, 1158
posterior deep, 1307
superficial, 1158
testicular, 829
terminal part of, 738
varieties, 829
thoracic, alar, 427
lateral, 427
somatic, 1244
superior, 426
thyro-cervical trunk, 1242
thyroid, inferior, 1242
superior, 1213 , 1242
thyroidea ima, 1038, 1204, 1221
tibial, anterior, 607
guide to, 599
recurrent, 609
posterior, 624
guide to, 599
recurrent, 609
varieties, 627
of tongue, 1346
of tonsils, 1215, 1355
tonsillar, of facial, 1217
transverse facial, 1158
tympanic, anterior, 1306
inferior, 1220
of tympanic membrane, 1677
ulnar, 475
collateral, 456
first part, 476
recurrent branches of, 477
second part, 480
third part, 487
varieties, 479. 49$
umbilical, 51, 9 2 3> io8 3
urachal, of superior vesical, 924
ureteric, of superior vesical, 924
uterine, 979
vaginal, 980
azygos, 980
of liver, 885
of uterine, 980
vas aberrans, brachial, 456, 475
to vas deferens, 738, 925
vertebral, at base of brain, 1447
development of, 1121, 1242
first part, 1241
fourth part, 1574
second part, 1241
third part, 1151
varieties of, 1242
vesical, inferior, 925
superior, 924
vestibular, 1694
zygomatic, 115 8
Articular discs— . .
of acromio-clavicular joint, 444
of mandibular joint, 1318
| Articular discs ( continued )—
of radio-ulnar joint, 520
of sterno-clavicular joint, 444
Articularis genu muscle, 573
Articular nerves—
ankle-joint, 610, 615, 627, 663
calcaneo-cuboid, 654
carpal joints, 507, 525
carpo-metacarpal, 526
elbow-joint, 461, 480, 519
hip-joint, 545, 574, 580, 597
intermetacarpal, 526
interphalangeal, foot. 653, 654
shoulder-joint, 432, 464
talo-calcanean, 615
tarsal, 614, 652, 654
tarso-metatarsal, 614, 652, 654
tibio-fibular, inferior, 550, 610, 660
intermediate, 660
superior, 550, 659
wrist-joint, 489, 507, 523
Aryepiglottic fold, 1386
development of, 73
Arytenoid cartilages, 1382
development of, 1383
Arytenoideus muscle, 1393
Aspera, linea, 350
Association fibres of cerebrum, 1568
Aster, 9, 10
Asterion, 180, 239, 251, 268, 1630
Atavism, 6
Atlanto-axial joints, 1404 , 1408
Atlanto-occipital joints, 1406, 1409
Atlas, 128
development of, 170
ossification of, 142
Atresia ani, 955
Atria of heart, left, 1052
interior of, 1059
right, 1051
interior of, 1054
of lung, 1027
Atrio-ventricular bundle, 1071
node, 1071
Atrium of middle meatus, 1357
Attraction particles, 9
sphere, 9
Atypical, definition, 6
Auditory artery, internal, 1448, 1576
cells, 1689, 1692
epithelium, 1689
hairs, 1689
meatus, external, 193 , 1671
internal, 190, 264
nerve, 1165, 1404, 1447, 1620
process, external, 194
radiation, 1531, 1568
striae, 1471, 1489, 1620
teeth, 1691
Auricle, 1294
blood-supply of, 1297
lymphatics of, 1297
muscles of, extrinsic, 1160
intrinsic, 1296
nerve-supply of, 1297
Auricle, structure of, 1295
veins of, 1297
Auricles of heart, left, 1052
right, 1051
Auricular artery, deep, 1305
posterior, 1219
nerve, great, 1142 , 1278
posterior, 1160, 1272
point, 251, 268, 1629
surface of sacrum, 147
tubercle, 1295
tubercles (emb.), 68
vein, posterior, 1161
Auricularis anterior muscle, 1160
posterior, 1160
superior, 1160
Auriculo-temporal nerve, 1157, 1277
Auscultation triangle, 400
Autonomic nervous system, 1634
parasympathetic, 1639
cranial, 1639
sacral, 1640
sympathetic, 1635
course of efferent impulses, 1636
development of, 1640
ganglia, 1635
rami communicantes, 1635
Axial filament in spermatozoon, 13
skeleton, 23
Axillary artery, 425
varieties of, 428
fascia, 414
folds, 412
lymphatic glands, 416, 424, 434 , 514
sheath, 429
space, 412, 422
vein, 428 , 451
Axis, 131
odontoid process of, 131
ossification of, 143
Azygos arteries of vagina, 890
veins, 839
Back, landmarks of, 397
of scalp and neck, 1141
Baillarger, bands of, 1565
Balfour’s cell-chain theory, 55
Ball-and-socket joint, 393
Band, diagonal, 1515
ilio-trochanteric, 593
moderator, 1057
pudendal, 929
sciatic, 929
Basal cartilaginous plate in skull, 89
ganglia, 1526
Base of brain, 1443
Base-line of Reid, 1633
Basi-bregmatic axis, 260
Basi-cranial axis, 260
Basi-facial axis, 260
Basi-hyal, 236
Basilar artery, 1447, 1575
branches of, 1447, 1575
groove, 174
membrane, 1690
Basilar, part of occipital bone, 174
vein, 1521, 1579
Basilic vein, 450, 451
Basi-occipital, 275
Basion, 258, 268
Basket cells of cerebellum, 1487
Beak of ulna, 312
Bechterew, band of, 1565
Bellini, duct of, 903
Bergmann, fibres of, 1487
Biceps brachii, 452 , 463
third head, 454
femoris, 542
Bicipital aponeurosis, 453
groove, 300
synovial sheath, 465
Bifurcated ligament—•
calcaneo-cuboid part, 666
calcaneo-navicular part, 665
Bile canaliculi, 886
capillaries, 886
ducts, 779
accessory ducts, 779
interlobular ducts, 886
Birth of foetus, 107
Biventer cervicis muscle, 407
Bladder, urinary, blood-supply of, 952
development of, 955
female, 977
infantile, 952
ligaments of, false, 918, 952
true, 952
lumen of empty bladder, 951
male, 932
nerve-supply of, 953
orifices of, 951
peritoneal relations of, 934
structure of, 949
trigone, external, of, 934
internal, of, 951
Blastocele, 24
Blastocyst, 24
Blastoderm, 24
Blastodermic vesicle, 24
Blastomere, 21
Blastopore, 35
Blastula, 24
Blind spot, 1653
Blood circulation, development of, so, s
islands, 51
Bochdalek, ganglion of, 1320
Body, ano-coccygeal, 675
carotid, 1211
cavity, primitive, 23, 42
ciliary, 1647
geniculate, lateral, 1538
medial, 1538
Pacinian, 490, 653
perineal, female, 701
male, 681
pineal, 1540
ponto-bulbar, 1584
stalk, circulation in, 51, 52
morphology, 31 "
relation to umbilicus, 65
Body, ultimo-branchial, 76
vitreous, 1662
wall, development of, 59
split by pleurae, 78
Bone, canaliculi, 117
cell, 117
chemical, 115
lacunae, 117
marrow, 121
Bones, cancellated, 118
classification of, 118
compact, 116
of head, 172
ossification, 119
Borders, post- and pre-axial, 5
Bowman, capsule of, 901, 906
Brachia of corpora quadrigemina, 1538,
Brachial artery, 454, 456
collateral circulation after ligature, 457
profunda, 455
varieties of, 456
plexus, 439
infraclavicular branches, 431
in neck, 1193
supraclavicular branches, 430,
Brachialis muscle, 454
Brachio-radialis, 501
Brachycephalic skulls, 243, 267, 269
Brain, 1442
development of, 55, 15 81
superior surface of, 1433
weight of, 1570
Bregma, 180, 237, 238, 268, 1629
Bregmatic bone, 265
Broca, area of, 1446
Bronchioles, 1027
development of, 1030
Bronchus, eparterial, 1027, 1030
hyparterial, 1027
development of, 1030
left, 1086
right, 1086
Bruch, membrane of, 1646
Bryant’s triangle, 552
Buccal mucous glands, 1272
Buccinator muscle, 1269
Bucco-pharyngeal area, 34, 44
fascia, 1179, I 3 68
membrane, 44, 56. 69
Bulb, olfactory, 1165, 1510 , 157 °
of penis, 682
of posterior horn, i 5 2 4
Bulbar ridges, 1079
Bulbo-urethral glands, 685
Bulbs of vestibule, 696
Bulla ethmoidalis, 1357
Bundle, atrio-ventricular, I ° 7 I
medial longitudinal, 1464, 1555
of Munzer, 1588
Bursa of biceps brachii, 453
femoris, 542, 641
of coraco-clavicular ligament, 405
Bursa, under gastrocnemius, 544, 619, 640
gluteal muscles, 598
of infraspinatus, 465
under obturator internus, 535
olecranon, 447
of popliteal tendon, 641
prepatellar, 554, 640
under semimembranosus, 544, 64°
subacromial, 436, 464
subhyoid, 235
subpsoas, 598
subscapular, 464
suprapatellar, 574, 640
of teres major, 465
Bursae at elbow-joint, 519
at hip-joint, 598
at knee-joint, 640
at shoulder-joint, 464
Caecum, 762
development of, 63, 882
peritoneal relations of, 763
varieties of, 764
vascular fold of, 792
Cajal, horizontal cells of, 1562
moss fibres of, 1488
Calamus scriptorius, 1452
Calcaneal arteries—
lateral of peroneal, 626
medial of post-tibial, 627
Calcaneo-cuboid joint, 666
Calcaneo-navicular ligament, plantar, 665,
part of bifurcated ligament, 665
Calcaneum, 370
ossification of, 378
peroneal tubercle, 372, 388
structure of, 372
sustentaculum tali of, 371, 388, 390
tubercles on, 370, 386
tuberosity of, 370
varieties of, 372
Calcar avis, 1524
femorale, 354
Calcarine area of cortex, 1569
artery, 1577
Callosal radiation, 1568
Calvaria, 260
Canal or canals—
anal, 945, 97 8
carotid, 189, 191, 258, 263
central, of cord, 1422
condylar, 175, 258
cranio-pharyngeal, 197, 206
dental, 212, 213
facial, 190
femoral, 566
Haversian, 116
hepatic, 886
hyaloid, 1664
incisive, 248
infra-orbital, 245
inguinal, 708, 735
innominate, 201
Canal or canals—( continued )
intestinal, 761
lacrimal, 245
mandibular, 231
naso-lacrimal, 248
neural, 40
of Nuck, 743, 744, 969
obturator, 993
palatine, greater and lesser, 255
palato-vaginal, 199, 255
palmar, 332
pharyngo-tympanic, 257
portal, 885
pterygoid, 204, 255, 263
pterygo-palatine, 227
pudendal, 688
pyloric, 760
of sacrum, 148
semicircular, 1684
spiral, of cochlea, 1685
subsartorial, 580
vertebral, 154
Volkmann's, 117
zygomatico-facial, 219
zygomatico-temporal, 219
Canaliculus for chorda tympani, anterior,
187, 1673
posterior, 190, 1675
lacrimal, 1287
mastoid, 191, 258
tympanic, 258
Cancellated bone, 118
Canine fossa, 212
ridge, 211
teeth, 280
Capitate bone, 320
ossification of, 322
Capitellum, definition, 114
Capitulum of humerus, 304
Capsular decidua, 104, 106
Capsule, external, of brain, 1531
internal, of brain, 1528
Caput cornu, 1421
gyri hippocampi, 1507
medusae, 712
Cardiac nerves of sympathetic cervical,
1334 . 1335
of vagus, cervical, 1330
thoracic, 1045
plexus, 1046
deep, 1046
superficial, 1046
Cardinal veins, 51, 1127, 1132, 1136
Carotico-clinoid foramen, 200
Carotid artery, common, 1207
left, in thorax, 1039
external, 1212
development of, 1119, 1213
internal, 1169, 1323, 1324, 1399'
development of, 91, 1118,
1122, 1324
body, 1211
canal, 189, 191, 258, 263
groove of sphenoid, 200
Carotid notch of sphenoid, 200
plexus, 1333
sheath, 1207
triangle, 1196
tubercle, 134, 1172
Carpal arch, posterior, 478, 508, 511
anterior, of radial, 475
posterior, of radial, 511
of ulnar, 479
joints, 524
rete, anterior, 478, 479, 498
Carpo-metacarpal joints, 525
Carpus, 315
morphology, 323
ossification of, 322
varieties of, 322
as a whole, 321
Cartilage or cartilages—
arytenoid, 1382
corniculate, 1383
costal, 160
cuneiform, 1383
of larynx, 1379
of mandibular arch, 74, 75, 232
nasal, 1298
of second arch, 75
semilunar, 632
thyroid, 1380
Cartilaginous base of skull, 89, 270, 275
Cartilago triticea, 1384
Caruncula lacrimalis, 1289, 1292
Carunculae hymenales, 696
Cauda equina, 1417
Caudal, definition, 122
Caudate nucleus, 1526
Cave of Retzius, 339
Cavernous sinus, 1169, 1606
Cavity, glenoid, 294 , 461
of larynx, 1386
nasal, 1356
of septum lucidum, 1520
thoracic, 1002
Cavum trigeminale, 1167
Cell, animal, 8
of Cajal, 1562
division, 9
germ, 12
of Golgi, 1564
membrane, 8
pyramidal, 1562
Cement, 285
Centra, vertebral development, 59
Central artery of retina, 1260, 1658
canal of cord, 1422
lobule of cerebullum, 1478
tendon of diaphragm, 835
Centrale, os, 322
Centro-acinar cells of Langerhans, 891
Centrosome, 9, 10, 21
in spermatozoa, 13
Centrum of vertebrae, 125
Cephalic, definition, 122
vein, 450, 451
Cerg,to-hyal, 76, 23$
I 7 2 3
Cerebellar fossae, 264
Cerebelli, tentorium, 1163, 1602, 1633
Cerebellum, 1475
arbor vitae of, 1485
association and commissural fibres
of, 1485
basal surface, 1443
development of, 1488, 1586
lobes and lobules of under surface
of, 1480
of upper surface, 1478
medullary vela, 1485
morphology of, 1481
nuclei of, i486
peduncles, inferior, 1484
middle, 1484
superior, 1483 , 1553
structure of, i486
under surface of, 1479
upper surface of, 1476
Cerebral commissure, anterior, 1518, 1568
hippocampal, 1518, 1568
posterior, 1542
cortex, 1561
development, 1510, 1591
fissures of, 1495
calcarine, 1503
choroidal, 1525
collateral, 1497
dentate, 1508
ecto-rhinal, 1508
lateral, 1495
parieto-occipital, 1496
postcalcarine, 1503
precalcarine, 1503
ganglia, basal, of, 1526
gyri of, 1493. See under Gyri
hemispheres, 1493
lobes of—
frontal, 1497
insula, 1505
limbic, 1506
occipital, 1502
olfactory, 1510
parietal, 1499
pyriform, 1508
temporal, 1504
lobules of—
cuneus, 1504
paracentral, 1499
parietal, 1501
postcentral, 1506
prsecuneus, 1502
precentral, 1506
quadrate, 1502
pole, frontal, of, 1451
occipital, of, 1451, i 5°3
temporal, of, 1444
veins, 1578
vesicles, primary, 58
Cerebri, crura, 1445. 1551
Cerebro-spinal axis, 1410
Cerebrum, the, 1493
Ceruminous glands, 1672
Cervical canal in pregnancy, 104
Cervical fascia, deep, 1178
compartments of, 1180
fistula, 1377
lymphatic glands, deep, 1189, H 99
superficial, 1178
plexus, 1185
branches, deep, 1188
superficial, 1141, 1187
spinal nerves, origins of, 1418
vertebrae, 126
Cervix cornu of cord, 1421
of uterus, 973
Check ligaments of eyeball, 1253
Cheeks, 1337
Chiasma, optic, 1545
Chondrocranium, 89, 270, 275
Chorda tympani nerve, 1347, 1402
Chordae tendineae, 1057
Chorio-decidual vessels, 109
Chorion, 29, 106
Chorionic ectoderm 29
mesoderm, 29
villus, 29
Choroid coat of eyeball, 1645
nerves of, 1651
structure of, 1646
plexus of fourth ventricle, 1492
of lateral ventricle, 1521
of inferior horn of, 1525
of third ventricle, 1521
Choroidal fissure, 1525
Chromatin, 9
discharged from nucleus, 18
Chromosomes, 10, 17, 18
Chyli, cisterna, 838, 1100
Ciliary body of eye, 1647
ganglion, 1257
margin, 1649
nerves, long, 1256
short, 1258
processes, 1647
vessels, 1260, 1651
Cinereum, tuber, 1445* 1544
Cingulate sulcus, 1496
Circular folds of small intestine, 864
sinus, 1606
sulcus, 1497
Circulation, course of, 1050
embryonic, 51
Circulus arteriosus, 1449, 1 577
major, 1651
minor, 1651
Circumduction, 395
Circumflex artery, anterior humeral, 427
fibular, 609
lateral femoral, 585, 588
medial femoral, 585, 589
posterior humeral, 427, 428
scapular, 427
iliac artery, deep, 732
superficial, 584, 712
nerve, 432 , 436
Cisterna basalis, 1609
cerebello-medullaris, 1609
chyli, 838, 1100
Cisterna pontis, 1609
venae magnae, 1609
Classification of joints, 394
of movements, 395
Claustrum, 1531
Clava of medulla oblongata, 1455
Clavicle, 289
in female, 291
ossification of, 292
structure of, 291
varieties of, 291
Clavi-pectoral fascia, 420
Cleavage nucleus, 21
Cleft, intratonsillar, 1354
palate, varieties of, 218
uro-genital, 693
Clinoid process, anterior, 200 , 261
middle, 200 , 261
posterior, 198 , 261
Clitoris, 694
arteries of, 703
development of, 698
frenulum, 694
glans, 695
lymphatics of, 695
prepuce, 695
Clivus monticuli, 1478
of sphenoid, 197, 264
Cloaca, 45, 99, 954
division of, 98
Cloacalfossa, 956
membrane, 45, 955, 956
septum, 99, 954
Closing membrane, 66
Coats of eyeball, 1641
Coccygeal plexus, 531
Coccygeus muscle, 948
Coccyx, 149
cornua of, 150
ossification of, 151
varieties, 151
Cochlea, 1685, 1689
aqueduct of, 193, 1165, 1686
Coeliac artery, 811
ganglia, 809
plexus, 807, 809
Coelom, 23, 29, 65
extra-embryonic, obliterated,
Coils of intestine, formation, 63
Collateral fissure, 1497
Colliculus facialis, 1491
Colon, ascending, 766
descending, 767
iliac part of, 767
left flexure of, 767
pelvic, 943
right flexure of, 766
taeniae of, 768, 870
transverse, 766
Column, vertebral, 124
as a whole, 151
Columnae rugarum, 986
Columns, anal, 961
renal, 900