upper side of the globe is turned inwards, and the
inferior part to the outside of the orbit, and the
whole globe drawn forwards towards the inner
canthus.

Obliquus major, Winslow.



THE MUSCLES. 33

2. OBLIQUUS INFERIOR,

Arises, by a narrow beginning, from the outer
edge of the orbitar process of the superior maxil-
lary bone, near its juncture with the os unguis ;
and, running obliquely outwards, is

Inserted into the sclerotica, in the space between
the abductor and optic nerve, by a broad thin
tendon.

Use. To draw the globe of the eye forwards,
inwards, and downwards, and, contrary to the
superior, to turn the pupil upwards, towards the
inner extremity of the eyebrow ; at the same time,
the external part of the globe is turned towards
the inferior side, -and the internal rolls towards the
upper part.

Obliquus minor, Winslow.



CHAP. V.

OF THE MUSCLE OF THE NOSE.

THERE is only one muscle on each side that
can be called proper to the nose, though it is af-
fected by several muscles of the face.

COMPRESSOR NARIS,*



* This muscle is situated between the skin and cartilaginous por-
tion of the nose. Its origin is united with some fibres of the levator,
labii superioris alaeque nasi, and its upper margin with the occi-
pito-frontalis.



14 DESCRIPTION OF

Arises^ by a narrow beginning, from the root
of the ala nasi externally, where part of the le-
vator labii superioris alaeque nasi is connected to
it; it spreads into a number of thin disgregated
fibres, which run up along the cartilage in an
oblique manner, towards the dorsum of the nose,
where it joins with its fellow, and is

Inserted slightly into the anterior extremity of
the os nasi and nasal process of the superior
maxillary bone, where it meets with some of the
fibres descending from the occipito-frontalis
muscle.

Use. To compress the ala towards the septum
nasi, particularly when we want to smell acutely ;
but, if the fibres of the frontal muscle which ad-
here to it act, the upper part of this thin muscle
assists to pull the ala outwards. It also corrugates
the skin of the nose, and assists in expressing
certain passions.

Rinteus, vel nasalts, Douglas.



CHAP. VI.
MUSCLES OF THE MOUTH AND LIPS.

THE mouth has nine pair of muscles, which
are inserted into the lips, and a common one

* Before these muscles are dissected, the mouth of the subject
should be filled with hair or tow till completely distended, when
the lips should be neatly sewed together. By thus distending the
muscles, they will be more easily discovered, and their dissection
materially facilitated.



THE MUSCLES. 15

formed by the termination of these, viz. three
above, three below, three outwards, and the com-
mon muscle surrounds the mouth.

The three above are,

1. LEVATOR ANGULI ORIS,*

Arises, thin and fleshy, from the hollow of the
superior maxillary bone, between the root of the
socket of the first dens molaris and the foramen
infra-orbitarium.

Inserted into the angle of the mouth and under-
lip, where it joins with its antagonist.

Use. To draw the corner of the mouth up-
wards, and make that part of the cheek opposite
to the chin prominent, as in smiling.

Elevator labiorum communis, Douglas.

Caninus, Winslow.

2. LEVATOR LABII SUPERIORIS AJL32QUE NASI,-f-

Arises by two distinct origins ; the first broad
and fleshy, from the external part of the orbitar
process of the superior maxillary bone which



* The levator aiiguli oris is situated upon the superior jaw along
the outer edge of the levator .labii superioris alaeque nasi, and in
part covered by that muscle. It is also partly concealed by the
xygomatici, and intimately connected at its insertion with the de-
pressor anguli oris.

f- Some describe this as two distinct muscles ; but the two por-
tions of which it is composed cannot be separated without dividing
some of the fibres. They ought, therefore, to be regarded as a
single muscle. It is situated superficially, and removed in a small
degree only from the alae of the nose. The origins of the muscle
are covered by the orbicularis palpebrarum.



16 DESCRIPTION OF

forms the lower part of the orbit, immediately
above the foramen infra orbitarium ; the second
portion arises from the nasal process of the supe-
rior maxillary bone, where it joins the os fronds
at the inner canthus descending along the edge of
the groove for the lachrymal sac. The first and
shortest portion is

Inserted into the upper lip and orbicularis
labiorum; the second and longest, into the upper
lip and outer part of the ala nasi.

Use. To raise the upper lip towards the orbit,
and a little outwards ; the second portion serves
to draw the skin of the nose upwards and out-
wards, by which the nostril is dilated.

Elevator labii superioris proprius, Douglas.

Inctsivus lateralis, First portion ; Pyramidalis,
Second portion ; Winslow.

3. DEPRESSOR LABII SUPERIORIS AL^EQUE NASI, *

Arises, thin and fleshy, from the os maxillare
superius, immediately above the joining of the
gums with the two dentes incisivi, and the dens
caninus-; from thence it runs up under part of
the levator labii superioris alaeque nasi.

Inserted into the upper lip and root of the ala
nasi.

Use. To draw the upper lip and ala nasi
downwards and backwards.



* The easiest method of exposing this muscle is by inverting
the upper lip, and dissecting by the side of the frenum. For a
considerable extent it lies close to the superior jaw bone, and is
covered by the levator labii swperioris alaeque nasi et orbicularis
oris.



THE MUSCLES. 17

Depressor alte nast, Albinus. s

Incisivus mediusy Winslow.

Depressor labii superioris proprius, Douglas,

The three below are,

1. DEPRESSOR ANGULI ORIS, *

Arises, broad and fleshy, from the lower edge
of the maxilla inferior, at the side of the chin,
being firmly connected to that part of the pla-
tysma myoides, which runs over the maxilla to
the angle of the mouth, to the depressor labii
inferioris within, and to the skin and fat without,
gradually turning narrower ; and is

Inserted into the angle of the mouth, joining
with the zygomaticus major and levator anguli oris.

Use. To pull down the corner of the mouth.

Triangularis, Winslow.

Depressor labiorum communis y Douglas.

2. DEPRESSOR LABII INFERIORIS, (

Arises, broad and fleshy, intermixed with fat,
from the inferior part of the lower jaw next the
chin ; runs obliquely upwards ; and is

Inserted into the edge of the under-lip, extends

* The origin of this muscle is situated between the skin and
depressor labii inferioris, and intermixed with some fibres of the
platysma myoides and buccinator. Its insertion is particularly
united to the levator anguli oris.

j- Great care is requisite in dissecting this muscle, as it is firmly
united to the skin, and intermixed with fatty matter. Its origin is
situated behind the depressor anguli oris ; in its course it covers
the levator labii inferioris, and at its insertion mixes with the fibres
tf its fellow.



J8 DESCRIPTION OF

along one half of the lip, and is lost in its red
part.

Use. To pull the under lip and the skin of
the side of the chin downwards, and a little
outwards.

Quadratus, Winslow.

Depressor labii inferioris proprius, Douglas.

3. LEVATOR LABII INFERIORIS, *

Arises, from the lower jaw, at the roots of the
alveoli of two dentes incisivi and of the caninus ;
is

Inserted into the under lip and skin of the chin.

Use. To pull the parts into which it is inserted
upwards.

Levator menti, Albinus.

Incisivus inferior, Winslow.

Elevator labii inferioris proprius, Douglas.

The three outward are,
:

1. BUCCINATOR, (

Arises, tendinous and fleshy, from the lower



* By inverting the lower lip and dissecting by the side of the
frenum this muscle will be discovered. Or, from without, it may
be found by cutting between the depressores labii inferioris, and
turning one of these aside. The muscle is situated in the promi-
nence of the chin, and covered by the depressor labii inferioris.

f- The Buccinator is situated close upon the lining membrane of
the mouth, and covered by much fatty matter. It is partly con-
cealed likewise by other muscles, as the zygomaticus major, pla-
tysma myoides, levator and depressor anguli oris. Opposite the
third grinding tooth of the superior jaw, it is perforated by the
parotid duct.



THE MUSCLES. 19

jaw, as far back as the last dens molaris and
forepart of the root of the coronoid process ;
fleshy from the upper jaw, between the last dens
molaris and pterygoid process of the sphenoid
bone ; from the extremity of- which it arises ten-
dinous, being continued between both jaws to the
constrictor pharyngis superior, with which it joins ;
from thence proceeding with straight fibres, and
adhering close to the membrane that lines the
mouth, it is

Inserted into the angle of the mouth within the
orbicularis oris.

Use. To draw the angle of the mouth back-
wards and outwards, and to contract its cavity, by
pressing the cheek inwards, by which the food is
thrust between the teeth.

Retractor anguli arts, Albinus.

. , ; , 2. ZYGOMATICUS MAJOR, *

Arises, fleshy, from the os malse, near the
zygomatic suture.

Inserted into the angle of the mouth, appearing
to be lost in the depressor anguli oris and orbicu-
laris oris.

Use. To draw the corner of the mouth and
under-lip towards the origin of the muscle, and
make the cheek prominent, as in laughing.

Zygomaticus, Douglas.

* This muscle is situated superficially, except at its origin, where it
is covered by the orbicularis palpebrarum. It descends upon the
outer side of the zygomaticus minor, and crosses the masseter
and buccinator, but is separated from them by considerable quan-
tities of fat.



20 DESCRIPTION OF

3. ZYGOMATICUS -MINOR, *

.Arises from the upper prominent part of the
Os malae, above the origin of the former muscle ;
and, descending obliquely downwards and for-
wards, is

Inserted into the upper-lip, near the corner of
the mouth, along with the levator anguli oris.

Use. To draw the corner of the mouth ob-
liquely outwards, and upwards, towards the ex-
ternal canthus of the eye.

This muscle is frequently wanting.

The common muscle is the

ORBICULARIS ORIS. -J-

This muscle is, in a great measure, formed by
the muscles that move the lips : the fibres of the
superior descending, those of the inferior as-
cending, and decussating each other about the
corner of the mouth, run along the lip to join
those of the opposite side, so that the fleshy .fibres
appear to surround the mouth like a sphincter.

Use. To shut the mouth, by contracting and
drawing both lips together, and to counteract all
the muscles that assist in forming it.

* The, origin of the zygomaticus minor is covered by the orbi-
cularis palpebrarum. Having cleared that muscle it descends
superficially nearer the nose than the zygomaticus major, and upon
the outer edge of the levator labii superioris alaeque nasi.

"\" Some anatomists describe this as a double semi-orbicular muscle,
decussating at the angles of the mouth. The greater number, how-
ever, more justly view it as a single sphincter formed chiefly from
the neighbouring muscles. It should be cautiously dissected in the
course of its fibres, else it will be very imperfectly displayed.



j



THE MUSCLES.

Sphincter labiorum, Douglas.

Semi orbicularis, Win slow.

Constrictor om, Cowper.

There is another small muscle described by Al-
binus, which he calls Nasalis labii superioris ; but
it seems to be only some fibres of the former con-
nected to the septum nasi.



CHAP. VII.

MUSCLES OF THE LOWER JAW.

THE lower jaw has four pair of muscles for its
elevation or lateral motions, viz. two, which are
seen on the side of the face, and two concealed
by the angle of the jaw.

~

1. TEMPO RALIS, *

Arises, fleshy, from a semicircular ridge of the
lower and lateral part of the parietal bone, from
all the pars squamosa of the temporal bone, from
the external angular process of the os frontis, from
the temporal process of the sphenoid bone, and
from an aponeurosis which covers it : from these



* The name of this muscle indicates its situation. It may ap-
pear to be quite superficial, but upon a careful examination will be
found covered at its origin by the tendinous edge of the occipito-
frontalis. The body of the muscle is likewise partly concealed by
the small muscles of the ear, and after passing the zygoma, its
insertion is entirely hid by the masseter. A puncture of this
muscle whilst opening the temporal artery which runs upon its sur-
face, has given rise to locked jaw and other serious tetanic affections.



22 DESCRIPTION OF

different origins the fibres descend like radii to-
wards the jugum, under which they pass ; and are

Inserted, by a strong tendon, into the upper part
of the coronoid process of the lower jaw ; in the
duplicature of which tendon this process is in-
closed as in a sheath, being continued down all its
fore part to near the last dens molaris.

Use. To pull the lower jaw upwards, and press
it against the upper, at the same time drawing it
a little backwards.

N. B. This muscle is covered by a tendinous
membrane, called its aponeurosis, which arises
from the bones that give origin to the upper and
semicircular part of the muscle ; and, descending
over it, is inserted into all the jugum, and the ad-
joining part of the os frontis.

The use of this membrane is to give room for
the origin of a greater number of fleshy fibres, to
fortify the muscle in its action, and to serve as a
defence to it.

Crotaphite mnscle, Winslow.

2. MASSETER, *

Arises, by strong, tendinous, and fleshy fibres,
which run in different directions, from the supe-
rior maxillary bone, where it joins the os malse,
and from the inferior and interior part of the



* The greater part of this muscle is superficial. It is situated
upon the ascending plate of the superior maxillary bone. Its upper
part is crossed by the zygomaticus major ; below, it is overlapped
by some fibres of the platysma myoides : the parotid gland covers
its posterior edge : the labial artery ascends along its anterior mar-
gin, and the muscle is crossed about its middle by the parotid duct.



THE MUSCLES. 23

zygoma, its whole length, as far back as the tu-
bercle before the socket for the condyle of the
lower jaw; the external fibres slanting backwards,
and the internal forwards.

Inserted into the angle of the lower jaw, and
from that upwards to near the top of its coronoid
process.

Use, To pull the lower to the upper jaw, and,
by means of its oblique decussation, a little for-
wards and backwards.

3. PTERYGOIDEUS INTERNUS, *

Arises, tendinous and fleshy, from the inner and
upper part of the internal plate of the pterygoid
process, filling all the space between the two

plates ; and from the pterygoid process of the os
r r j& f

palati between these plates.

Inserted into the angle of the lower jaw inter-
nally.

Use. To draw the jaw upwards, and obliquely
towards the opposite side.

Pterygoideus major, Winslow.



* The Pterygoidei muscles lie behind the ascending plate of the
lower jaw, and cannot be well exposed without a section of that bone.
Some have recommended that the jaw should be dislocated and
drawn forwards ; others that the bone should be divided at the sym-
phisis, and the opposite half removed, when an internal view of the
muscles will be obtained. Less injury will be done to the neighbour-
ing parts, and the muscles clearly exposed by making two sections of
the lower jaw ; one about half an inch nearer the symphisis than its
angle, and another midway between the angle and neck of the bone.
The muscles cross each other, and are connected by a considerable
quantity of loose cellular substance, in which the gustatory divi-
sion of the fifth pair of nerves, and the inferior maxillary artery, are
situated.



24 DESCRIPTION OF

4. PTERYGOIDEUS EXTERNUS,

Arises from the outer side of the external plate
of the pterygoid process of the sphenoid bone,
from part of the tuberosity of the os maxillare
adjoining to it, and from the root of the temporal
process of the sphenoid bone.

Inserted into a cavity in the neck of the con-
dyloid process of the lower jaw ; some of its fibres
are inserted into the ligament that connects the
moveable cartilage and that process to each other.

Use. To pull the lower jaw forwards, and to
the opposite side ; and to pull the ligament from
the joint, that it may not be pinched during these
motions : when both external pterygoid muscles
act, the foreteeth of the under jaw are pushed for-
ward beyond those of the upper jaw.

fterygoideus minor, Winslow.



CHAP. VIII.

THE MUSCLES WHICH APPEAR ABOUT THE
ANTERIOR PART OF THE NECK,

ON the side of the neck are two muscles or
layers.

* The student cannot bestow too much attention on the muscles
of the neck. Their relation to the neighbouring parts ought par-
ticularly to be studied, and these are neither few nor unimportant.
Indeed there is not another portion of the body of the same mag-
nitude in which such a number of really interesting parts are
congregated. In the middle of the neck anteriorly are the larynx,



THE MUSCLES. 25,

1. MUSCULUS CUTANEUS,

VULGO,

PLATYSMA MYOIDES, *

Arises, by a number of slender disgregated
fleshy fibres, from the cellular substance that covers
the upper part of the deltoid and pectoral mus-
cles ; in their ascent they all unite to form a thin
muscle, which runs obliquely upwards along the
side of the neck, adhering to the skin.

Inserted into the lower jaw, between its angle
and the origin of the depressor anguli oris, to
which it is firmly connected, and but slightly to
the skin that covers the inferior part of the mas-
seter muscle and parotid glands.

Use. To assist the depressor anguli oris in
drawing the skin of the cheek downwards; and,
when the mouth is shut, it draws all that part of
the skin, to which it is connected, below the lower
jaw, upwards.



the trachea, the thyroid gland, and behind these, the esophagus.
On each side of the trachea, the great blood-vessels which carry
the blood to the brain, and return it again to the heart, and the
nerves which are destined for the thoracic and abdominal viscera, are
situated. All these are connected together by cellular substance,
and interspersed with numerous lymphatic glands. The dissection
ought, therefore, to be conducted with great care, lest any thing
important be omitted or removed.

* If we except the occipito frontaiis, another muscle like this
will not be found in the whole body. It is rather a muscular mem-
brane than a muscle, connected to the inner surface of the skin
by condensed cellular substance, and in emaciated subjects is often
so thin and pale, that it can with difficulty be recognised. The young
dissector is apt to remove it along with the skin. It should be dis-
sected in the course of its fibres, and afterwards raised from the
breast, that the subjacent muscles may be exposed.

c



26 DESCRIPTION OF

Platysma myoides, Galen.

Musculus cutaneus, Winslow.

Quadratus gen*, vel Latissimus colli, Douglas.

Latissimus colli, Albinns.

2. STERNO-CLE1DO MASTOIDEUS, *

Arises by two distinct origins; the anterior,
tendinous and a little fleshy, from the top of the
sternum near its junction with the clavicle ; the
posterior, fleshy, from the upper and anterior part
of the clavicle ; both unite a little above the an-
terior articulation of the clavicle, to form one
muscle, which runs obliquely upwards and out-
wards, to be

Inserted, by a thick strong tendon, into the
mastoid process, which it surrounds; and, gra-
dually turning thinner, is inserted as far back as
the lambdoid suture.

Use. To turn the head to one side, and bend
it forwards.

Ster no-mast oideus and Cleido-mastoideus, Albinus.

Mastoideus, Douglas.



* This muscle is situated obliquely at the lateral part of the neck im-
mediately under the platysma myoides. It is often perforated by a
number of small cervical nerves, and always about its middle by the
spinal accessory. Along the tracheal edge of the muscle the carotid
artery will be found inclosed in a sheath of cellular substance, along
with the per vagum nerve and internal jugular vein. The descend-
ensnoni, a branch of the ninth pair of nerves, lies upon the anterior
surface of this sheath, and the great sympathetic nerve upon the pos-
terior. Wry neck has originated from a permanent contraction of this
muscle, and been cured by dividing the muscle] near its origins.






THE MUSCLES. 27

CHAP. IX.



MUSCLES SITUATED BETWEEN THE LOWER
JAW AND OS HYOIDES.

THERE are four layers before, and two muscles
at the side ;

The four layers are,

1. DIGASTRICUS, *

Arises, by a fleshy belly, intermixed with ten-
dinous fibres, from the fossa at the root of the
mastoid process of the temporal bone, and soon
becomes tendinous ; runs downwards and for-
wards: the tendon passes generally through the
stylo-hyoideus muscle ; then it is fixed by a liga-
ment to the os hyoides ; and, having received from
that bone an addition of tendinous and muscular
fibres, runs obliquely forwards, turns fleshy again,
and is

Inserted, by this anterior belly, into a rough
sinuosity at the inferior and anterior edge of that
part of the lower jaw called the chin.



* By removing the platysma myoides, both portions of this muscle
are brought into view. The origin, however, of the posterior portion,
or belly, is covered by the trachelo mastoideus, splenius capitis and
sterno-cleido mastoideus. The sub-maxillary gland lies in the trian-
gular space formed by the lower jaw and the two bellies of this
muscle. The gland lies chiefly on the mylo-hyoideus, and when
the base of the scull is [parallel with the horizon, is situated within
the protection of the lower jaw. When the chin is raised the gland
advances forwards, and becomes more exposed.



28 DESCRIPTION OF

Use. To open the mouth, by pulling the lower
jaw downwards and backwards ; and when the
jaws are shut, to raise the larynx, and consequently
the pharynx, upwards, as in deglutition.

Biventcr maxilla inferioris, Albinus.

2. MYLO-HYOIDEUS, *

Arises, fleshy, from all the inside of the lower jaw
between the last dens molaris and the middle of
the chin, where it joins with its fellow,

Inserted into the lower edge of the basis of the
os hyoides, and joins with its fellow.

Use. To pull the os hyoides forwards, up-
wards, and to a side.

3. GENIO-HYOIDEUS, (*

Arises, tendinous, from a rough protuberance
in the middle of the lower jaw internally, or inside
of the chin.

Inserted into the basis of the os hyoideus.

Use. To draw this bone forwards to the chin.



* The anterior belly of the digastricus covers a small portion of
this muscle, the rest of it being covered immediately by the sub-
maxillary gland. Before sending off its salivary duct, the gland
turns round the posterior margin of this muscle, and lies in contact
with its inner surface. The duct runs upwards and forwards, till it
opens in the mouth upon the side of the frenum linguae.

The sublingual gland is likewise situated upon the inner surface
of this muscle, or rather betwixt it and the lining membrane of the
mouth. It usually sends off a number of ducts which open in the
mouth near the root of the^ tongue.

f- By removing the mylo-hyoideus, this muscle is brought into
view. It lies so closely in contact with its fellow at the symphisis
of the chin, that the two may be mistaken for a single muscle.



THE MUSCLES. 29

4. GENIO-HYO-GLOSSUS, *

Arises, tendinous, from a rough protuberance
in the inside of the middle of the lower jaw ; its
fibres run, like a fan, forwards, upwards, and
backwards ; and are

Inserted into the tip, middle, and root of the
tongue, and base of the os hyoides, near its cornu.

Use. According to the direction of its fibres, to
draw the tip of the tongue backwards into the
mouth, the middle downwards, and to render its
dorsum concave ; to draw its root and os hyoides
forwards, and to thrust the tongue out of the
mouth.

The two muscles at the side are,

1. HYO-GLOSSUS, -f-

Arises, broad and fleshy, from the base, cornu,
and appendix of the os hyoides; the fibres run
upwards and outwards, to be

Inserted into the side of the tongue near the
stylo-glossus.

Use. To pull the tongue inwards and down-
wards.



* This muscle is not completely concealed by the genio-hyoideus.
A small portion of it, merely, which arises from the chin is covered
by that muscle : the remainder being covered by the mylo-hyoideus.