seventh and eighth ribs, run obliquely upwards
and backwards ; from the ninth and tenth, trans-
their surface. We then discover the diaphragm separating the tho-
rax from the abdomen, and other four muscles lying on each side of
the vertebral column.
The inferior surface of the diaphragm, only, can be seen in this
dissection, and in the natural state of parts is covered by the peri-
toneum, and in contact with the liver, stomach, and spleen. The
superior surface of the muscle is covered by the pleura, and in close
approximation with the lungs and pericardium, which encloses the
heart. The quadratus lumborum is an oblong square muscle, situ-
ated upon the lateral part of the lumbar vertebrae, between the psoas
magnus and transversalis. The psoas magnus lies nearer the spine
than the quadratus lumborum. The psoas parvus runs upon the
surface of the psoas magnus, and the iliacus internus is situated in
the concavity of the ilium, and descends to the ttiigh upon the external
margin of the psoas magnus. Upon carefully removing the perito-
neum from the last mentioned muscle, the facia iliaca will be discov-
ered. The facia iliaca is a thin membrane which runs upon the surface
of the iliac muscle, and is inserted into Poupart's ligament. It is sup-
posed to have a considerable effect in preventing the occurrence of her-
nia under that ligament. Where the femoral vessels pass, it is not in-
serted into Poupart's ligament, but gets behind the vessels to form
a part of the sheath which encloses them. As hernia is consequently
apt to occur at this point, it should be minutely examined by the
64 DESCRIPTION OF
versely inwards and upwards ; and from the ele-
venth and twelfth, obliquely upwards. From these
different origins the fibres run, like radii from the
circumference to the centre of a circle ; and are
Inserted into a cordiform tendon, of a consider-
able breadth, which is situated in the middle of
the diaphragm; and in which, therefore, the fibres
from opposite sides are interlaced. Towards the
right side the tendon is perforated by a triangular
hole, for the passage of the vena cava inferior; and
to the upper convex part of it the pericardium and
mediastinum are connected.
2. The Interior, Lesser Muscle, or Appendix of the
Arises from the second, third, and fourth lum-
bar vertebrae, by eight heads ; of which two in the
middle, commonly called its crura, are the longest,
and begin tendinous. Between the crura, the aorta
and thoracic duct pass; and on the outside of these,
the great sympathetic nerves and branches of the
vena azygos perforate the shorter heads. The
muscular fibres run obliquely upwards and for-
wards, and form in the middle two fleshy columns,
which decussate and leave an oval space between
them for the passage of the esophagus and eighth
pair of nerves.
Inserted, by strong fleshy fibres, into the poste-
rior part of the -middle tendon.
Use. The diaphragm is the principal agent in
respiration, particularly in inspiration ; for when it
is in action, the fibres, from their different attach-
ments, endeavour to bring themselves into a plane
THE MUSCLES. 65
towards the middle tendon, by which the cavity of
the thorax is enlarged, particularly at the sides,
where the lungs are chiefly situated; and as the
lungs must always be contiguous to the inside of
the thorax and upper side of the diaphragm, the
air rushes into them, in order to fill up the in-
creased space. This muscle is assisted by the two
rows of intercostals, which elevate the ribs, and
the cavity of the thorax is more enlarged. In time
of violent exercise, or whatever cause drives the
blood with unusual celerity towards the lungs, the
pectoral muscles, the serrati antici majores, the
serrati postici superiores, and scaleni muscles, are
brought into action. And in laborious inspiration,
the muscles which arise from the upper part of the
thorax, when the parts into which they are insert-
ed are fixed, likewise assist. In expiration, the
diaphragm is relaxed and pushed up by the pres-
sure of the abdominal muscles upon the viscera o
the abdomen ; and at the same time that they press
it upwards, they also, together with the sterno cos-
tales and serrati postici inferiores, pull down the
ribs, and are assisted in a powerful manner by the
elasticity of the cartilages that join the ribs to the
sternum ; by which the cavity of the thorax is di-
minished, and the air suddenly pushed out of the
lungs : and in laborious expiration, the quadrati
lumborum, sacrolumbales, and longissimi dorsi,
concur in pulling down the ribs.
The four pair are,
1 . QUADRATUS LUMBORUM,
Arises, pretty broad, tendinous and fleshy, from
the posterior part of the spine of the os ilium,
66 DESCRIPTION OF
Inserted into the transverse processes of the ver-
tebrae of the loins, into the last rib near the spine,
and by a small tendon into the side of the last ver-
tebra of the back.
Use. To move the loins to one side, pull down
the last rib, and, when both act, to bend the loins
Quadratus, seu Lumbaris externus, Winslow.
2. PSOAS PARVUS,
Arises, fleshy, from the sides of the two upper
vertebrae of the loins, and sends off a small long
tendon which ends thin and flat, and is
Inserted into the brim of the pelvis, at the junc-
tion of the os ilium and pubis.
Use. To assist the psoas magnus in bending the
loins forwards ; and, in certain positions, to assist
in raising the pelvis.
N. B. This muscle is very often wanting.
3. PSOAS MAGNUS.
Arises, fleshy, from the side of the body, and
transverse process of the last vertebra of the back ;
and, in the same manner, from all those of the
loins, by as many distinct slips.
Inserted, tendinous, into the trochanter minor
of the os femoris ; and fleshy into that bone, a lit-
tle below the same trochanter.
Use. To bend the thigh forwards ; or, when
the inferior extremity is fixed, to assist in bending
Psoas, seu Lumbaris internus, Winslow.
THE MUSCLES. 6?
4. ILLIACUS INTERNUS,
Arises, fleshy, from the transverse process of
the last vertebra of the loins, from all the inner
lip of the spine of the os ilium, from the edge of
that bone between its anterior superior spinous
process and the acetabulum, and from most of the
hollow part of the ilium. It joins with the psoas
magnus, where it begins to become tendinous ;
Inserted along with it.
Use. To assist the psoas in bending the thigh,
and to bring it directly forwards.
N. B. The insertion of the two last muscles
should not be prosecuted till the muscles of the
thigh are dissected.
MUSCLES SITUATED ON THE ANTERIOR
PART OF THE THORAX.*
THESE may be divided into two layers. The
first layer consists of one muscle, named
* Upon removing the skin and mammary gland, the pectoralis
major is brought into view. It is united to the deltoid by a line of
cellular substance, in which are imbedded the cephalic vein, and a
small thoracic artery. The sternal and clavicular portions of the mus-
cle are connected by a fatty line, which is worthy of observation, as
it can lead us to the subclavian artery. After the muscle has been
carefully dissected and examined, it should be raised from its origin
and suspended by its tendon. The deep-seated muscles will then be
68 DESCRIPTION OF
Arises from the cartilaginous extremity of the
fifth and sixth ribs, where it always intermixes
with the external oblique muscle of the abdomen ;
from almost the whole length of the sternum, and
from near half of the anterior part of the clavicle :
The fibres run towards the axilla in a folding man-
Inserted, by two broad tendons, which cross each
other at the upper and inner part of the os hu-
meri, above the insertion of the deltoid muscle,
and outer side of the groove for lodging the ten-
don of the long head of the biceps.
Use. To move the arm forwards and obliquely
upwards, towards the sternum.
Die second layer consists of three muscles ;
Arises, tendinous, from the cartilage that joins
the first rib to the sternum.
Inserted, after becoming fleshy, into the inferior
part of the clavicle, which it occupies from within
an inch or so of the sternum, as far outwards as to
exposed. The subclavius will be found between the clavicle and first
rib. The pectoralis minor lies immediately under the pectoraiis ma-
jor, and at its insertion, often blended with the origins of the short
head of the biceps and coraco-brachialis. The serratus magnus is
situated upon the lateral part of the chest, close upon the ribs, and
concealed in part by the scapula ; a portion of it is likewise covered
by the pectoralis major and minor.
THE MUSCLES, 69
its connexion, by ligament, with the coracoid pro-
process of the scapula.
Use. To pull the clavicle downwards and for-
2. PECTORALIS MINOR,
Arises, tendinous and fleshy, from the upper
edge of the third, fourth, and fifth ribs, near where
they join with their cartilages.
Inserted, tendinous, into the coracoid process of
the scapula ; but soon grows fleshy and broad.
Use. To bring the scapula forwards and down-
wards, or to raise the ribs upwards.
Serratus anticus, Albinus.
Serratus minor anticus, Douglas.
3. SERRATUS MAGNUS.
Arises from the nine superior ribs, by an equal
number of fleshy digitations, resembling the teeth
of a saw.
Inserted, fleshy, into the whole base of the sca-
pula internally, between the insertion of the rhom-
boid and the origin of the subscapularis muscles,
being folded about the two angles of the scapula.
Use. TO move the scapula forwards ; and, when
the scapula is forcibly raised, to draw upwards the
Serratus major anticus, Douglas,
70 DESCRIPTION OF
MUSCLES SITUATED BETWEEN THE RIBS,
AND WITHIN THE THORAX.
BETWEEN the ribs, on each side, there are ele-
ven double rows of muscles, which are therefore
named intercostals. These decussate each other
like the strokes of the letter X.
Arise from the inferior acute edges of each su-
perior rib, and run obliquely forwards, the whole
length from the spine to near the joining of the
ribs with their cartilages ; from which, to the ster-
num, there is only a thin membrane covering the
I?iserted into the upper obtuse edge of each in-
ferior rib, as far back as the spine, into which the
posterior portion is fixed.
Arise in the same manner as the external ; but
they begin at the sternum, and run obliquely back-
wards, as far as the angle of the rib ; and from
that to the spine they are wanting.
Inserted in the same manner as the external.
Use. By means of these muscles, the ribs are
equally raised upwards during inspiration. Their
fibres being oblique, give them a greater power of
bringing the ribs near each other, than could be
performed by straight ones. But, by the obliqui-
THE MUSCLES. 71
ty of the fibres, they are almost brought contigu-
ous ; and, as the fixed points of the ribs are be-
fore and behind, if the external had been continued
forwards to the sternum, and the internal back-
wards to the spine, it would have hindered their
motion, which is greatest in the middle, though
the obliquity of the ribs renders it less perceptible ;
and, instead of raising the fibres fixed to the ster-
num and spine, would have depressed the ribs.
N. B. The portions of the external intercostals
which arise from the transverse processes of the
vertebrae, where the ribs are fixed to them, and
other portions that pass over one rib and terminate
in the next below it, Albinus calls Levatores costa-
rum longiores et breviores.
The portions of the internal that pass over one
rib, and are inserted into the next below it, Dou-
glas calls Costarum depressores proprii Cowperii.
Supra-costales, and Infra-costales, Winslow.
The muscles within the thorax are one pair, viz.
TRIANGULARIS, OR STERNO COSTALIS,
Arises, fleshy, and a little tendinous, from all
the length of the cartilago ensiformis laterally, and
from the edge of the lower half of the middle bone
of the sternum, from whence its fibres ascend ob-
liquely upwards and outwards.
Inserted, generally by three triangular termina-
tions, into the lower edge of the cartilages of the
third, fourth, and fifth ribs, near where these join
with the ribs.
Use. To depress these cartilages, and the ex-
72 DESCRIPTION OF
tremities of the ribs ; and consequently to assist in
contracting the cavity of the thorax.
This muscle often varies ; and is sometimes in-
serted into the cartilage of the second rib, some-
times into the cartilage of the sixth rib.
MUSCLES SITUATED ON THE ANTERIOR PART
OF THE NECK CLOSE TO THE VERTEBRAE.
THESE consist of one layer, formed by four
1. LONGUS COLLI,
Arises, tendinous and fleshy, from the bodies of
* The muscles described in this chapter cannot be exposed till
the trachea and esophagus be removed.
The longus colliand rectus capitis internus major are situated be-
hind the pharynx, the esophagus, and principal vessels and nerves of
the neck, but connected to them by loose cellular substance. The
rectus capitis internus minor and rectus capitis lateralis are very
small muscles, which run between the first vertebrae and basis of the
cranium. The former is situated near the meisal line of the verte-
brse, and the latter at the side of the vertebral column behind the
jugular vein where it issues from the cranium. The scaleni mus-
cles lie upon the lower and lateral part of the neck, bounded
before by the platysma myoides, and sterno-cleido-mastoideus, and
behind by the trapezius and levator scapulas. They appear to be a
single muscle, but can easily be separated into three portions. The
brachial plexus of nerves and the subclavian artery, pass between
the anterior and middle scaleni to gain the axilla, while the sub-
clavian vein will be found before the scalenus anticus. Where the
subclavian artery issues from between these muscles, it can be com-
pressed on the first rib, or exposed by an incision, as in the opera-
tion for axillary aneurism.
THE MUSCLES. 73
the three superior vertebrae of the back laterally;
and from the transverse process of the third, fourth,
fifth, and sixth vertebrae of the neck, near their
Inserted into the fore part of the bodies of all
the vertebrae of the neck, by as many small ten-
dons, which are covered with flesh.
Use. To bend the neck gradually forwards, and
to one side.
2. RECTUS CAPITIS INTERNUS MAJOR,
Arises, from the anterior points of the trans-
verse processes of the third, fourth, fifth, and
sixth vertebrae of the neck, by four distinct be-
Inserted into the cuneiform process of the os
occipitis, a little before the condyloid process.
Use. To bend the head forwards.
Rectus anterior longus, Winslow.
3, RECTUS CAPITIS INTERNUS MINOR.
Arises, fleshy, from the fore-part of the body of
the first vertebrae of the neck, opposite to the su-
perior oblique process.
Inserted near the root of the condyloid process
of the os occipitis, under, and a little farther out-
wards than, the former muscle.
Use. To nod the head forwards.
Rectus anterior brevis, Winslow.
4. RECTUS CAPITIS LATERALIS,
Arises, fleshy, from the anterior part of the
74 DESCRIPTION OF
point of the transverse process of the first verte-
bra of the neck.
Inserted into the os occipitis, opposite to the
foramen stylo-mastoideum of the temporal bone.
Use. To bend the head a little to one side.
Transversalis anticus primus, Winslow.
On the side of the neck,
1. SCALENUS ANTICUS,
Arises, from the fourth, fifth, and sixth trans-
verse processes of the vertebrae of the neck, by as
Inserted, tendinous and fleshy, into the upper
side of the first rib, near its cartilage.
Scalenus prior, Albinus.
Anterior portion of the first scalenus, Winslow.
First scalenus, Douglas.
2. SCALENUS MEDIUS,
Arises, from all the transverse processes of the
vertebrae of the neck by as many strong tendons :
the nerves to the superior extremity pass between
it and the former.
Inserted into the upper and outer part of the
first rib, from its root, to within the distance of an
inch from its cartilage.
Posterior portion of the Jlrst scalenus, Winslow.
Second scalenus, Douglas.
3. SCALENUS POSTICUS,
Arises from the fifth and sixth transverse pro-
cesses of the vertebrae of the neck.
Inserted into the upper edge of the second rib,
not far from the spine.
Posterior portion of the second scalenus, Winslow.
Third scalenus, Douglas.
Use of the three scaleni : to bend the neck to
one side ; or, when the neck is fixed, to elevate the
ribs, and to dilate the thorax.
MUSCLES SITUATED ON THE POSTERIOR
PART OF THE TRUNK.*
THE following muscles are described as they
appear on dissection.
1. TRAPEZIUS, SEU CUCULARIS,
Arises, by a strong round tendon, from the
lower part of the protuberance in the middle of
The muscles situated on the posterior part of the trunk may
naturally be divided into three classes. 1st, the broad; 2dly, the
long ; and 3dly, the short muscles.
The Iroad muscles are the most superficial, and lie in three layers,
the trapezius and latissimus dorsi forming the first; the rhomboideus
and serratus posticus inferior, the second ; and the serratus posticus
superior, the third.
The long muscles lie immediately under the broad, and may be
divided into those of the back and those of the neck. In the back
three muscles are situated between the angles of the ribs and spinous
processes of the vertebrae, and form a single layer; they are the
sacro-lumbalis the longissimus dorsi, and spinalis dorsi. In the
neck the levator scapulae and splenius form the first layer, the tra-
chelo-mastoideus, transversallis colli and complexus, the second;
and the semi-spinalis colli the third. Great care and nicety are re-
76 DESCRIPTION OF
the os occipitis behind ; and, by a thin membranous
tendon, which covers part of the splenius and
complex us muscles, from the rough curved line
that extends from the protuberance towards the
mastoid process of the temporal bone ; runs down
along the nape of the neck, where it seems to
arise from its fellow, and covers the spinous pro-
cesses of the superior vertebrae of the neck ; but
arises from the spinous processes of the two infe-
rior, and from the spinous processes of all the
vertebras of the back ; adhering, tendinous, to its
fellow, the whole length of its origin.
Inserted, fleshy, into the posterior half of the
clavicle ; tendinous and fleshy, into the acromion,
and into almost all the spine of the scapula.
quisite in dissecting these muscles of the neck, for they are so
blended and entangled with each other, that they are apt to confuse
and bewilder the dissector.
The short muscles lie close to the spine under the long ones, and
chiefly run between the processes of the neighbouring vertebrae. Some
anatomists have described them with the utmost particularity, while
others have grouped nearly the whole together under the appellation,
multifidus spinae. The most remarkable of the short muscles are
those which are situated at the base of the cranium under the corn-
plexus, and which act upon the head, viz. the obliquus superior
and inferior, and rectus capitis major and minor.
To the surgical anatomist the muscles situated on the posterior
part of the trunk present few objects of consideration. If we except
the latissimus dorsi, there is not one of them that is interested in
any important surgical operation. But the latissimus dorsi forms
one of the boundaries of the axilla, a cavity containing such a num-
ber of important parts, all liable to disease, and often requiring sur-
gical operation, that it claims the undivided attention of the student.
The following are a few of the points which ought to be studied.
The form of the axilla ; its boundaries ; the course of the great
blood vessels and nerves in passing through it ; the relation of these
vessels and nerves to each other at the upper and lower part of the
cavity, with the principal situations of the lymphatic glands which
are lodged there.
THE MUSCLES. 77
Use, Moves the scapula according to the three
different directions of its fibres ; for the upper
descending fibres draw it obliquely upwards, the
middle transverse straight fibres draw it directly
backwards, and the inferior ascending fibres draw
it obliquely downwards and backwards.
N. B. Where it is inseparably united to its
fellow in the nape of the neck, it is named Liga-
mentum Nuchce 9 or Colli.
2. LATISSIMUS DORSI,
Arises, by a broad thin tendon, from the poste-
rior part of the spine of the os ilium, from all the
spinous processes of the os sacrum and vertebrae
of the loins, and from the seven inferior ones of
the vertebrae of the back; also, tendinous and
fleshy, from the extremities of the three or four
inferior ribs, a little beyond their cartilages, by as
many distinct slips. The inferior fibres ascend
obliquely, and the superior run transversely, over
the inferior angle of the scapula, towards the axil-
la, where they are all collected, twisted, and folded.
Inserted, by a strong thin tendon, into the inner
edge of the groove for lodging the tendon of the
long head of the biceps.
Use. To pull the arm backwards and down-
wards, and to roll the os humeri.
N. B. The insertion of this muscle should not
be prosecuted till the muscles of the os humeri,
to which it belongs, are dissected,
3. SERBATUS POSTICUS INFERIOR^
Arises, by a broad thin tendon, in common
78 DESCRIPTION OF
with that of the latissimus dorsi, from the spinal
processes of the two inferior vertebrae of the back,
and from the three superior of the loins.
Inserted into the lower edges of the four inferior
ribs, at a little distance from their cartilages, by
as many distinct fleshy slips.
Use. To depress the ribs into which it is inser-
This muscle is divided into two portions.
1. Rhomboldeus major, arises, tendinous, from
the spinous processes of the five superior vertebrae
of the back.
Inserted into all the basis of the scapula below
Use. To draw the scapula obliquely upwards
and directly inwards.
2. Rhomboideus minor, arises, tendinous, from
the spinous processes of the three inferior vertebrae
of the neck, and from the ligamentum nuchae.
Inserted into the base of the scapula, opposite to
Use. To assist the former.
5. SERRATUS SUPERIOR POSTICUS,
Arises, by a broad thin tendon, from the spinous
processes of the three last vertebrae of the neck,
and the two uppermost of the back.
Inserted into the second, third, fourth, and fifth
ribs, by as many fleshy slips.
Use. To elevate the ribs, and dilate the thorax.
THE MUSCLES. 79
6. LEVATOR SCAPULA,
Arises, tendinous and fleshy, from the transverse
processes of the five superior vertebrae of the neck,
by as many distinct slips, which soon unite to form
a muscle that runs downwards and outwards.
Inserted, fleshy, into the superior angle of the
Use. To pull the scapula upwards, and a little
Angularis, vulgo Levator proprtus, Winslow.
Elevator, seu Musculus patientiee, Douglas.
On the neck,
Arises, tendinous, from the four superior spin-
ous processes of the vertebrae of the back ; tendin-
ous and fleshy, from the five inferior of the neck,
and adheres firmly to the ligamentum nuchae. At
the third vertebrae of the neck, the splenii recede
from each other, so that part of the complexus
muscle is seen.
Inserted, by as many tendons, into the five su-
perior transverse processes of the vertebrae of the
neck; and tendinous and fleshy, into the poste-
rior part of the mastoid process, and into the os
occipitis, where it joins with the root of that pro-
Use. To bring the head and upper vertebrae
of the neck backwards laterally ; and when both
act, to pull the head directly backwards.
N* B. Albinus divides this muscle into two ;
80 DESCRIPTION OF
viz. That portion which arises from the five infe-
rior spinous processes of the neck, and is inserted
into the mastoid process and os occipitis, he calls
Splenius Capitis ; and that portion which arises
from the third and fourth of the back, and is in-
serted into the five superior transverse processes
of the neck, is called by him Splenius Colli.