Difference between revisions of "Book - Handbook of Pathological Anatomy 2.5"

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depress it.  
 
depress it.  
  
 
MYOLOGY.
 
 
 
109
 
  
  
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The anterior external layer is the longest and strongest, and covers  
 
The anterior external layer is the longest and strongest, and covers  
most of the lower. It is formed of fibres which are oblique from above  
+
most of the lower. It is formed of fibres which are oblique from above downward and from before backward, and become a little narrower  
 
 
 
 
110
 
 
 
 
 
DESCRIPTIVE ANATOMY
 
 
 
 
 
downward and from before backward, and become a little narrower  
 
 
from below upward. It arises by short tendinous fibres from the lower  
 
from below upward. It arises by short tendinous fibres from the lower  
 
edge of the malar bone, and is attached to the lower half of the ascending branch of the lower maxillary bone, as far as its inferior edge and  
 
edge of the malar bone, and is attached to the lower half of the ascending branch of the lower maxillary bone, as far as its inferior edge and  
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synonymous muscle of the other side.  
 
synonymous muscle of the other side.  
  
 
MYOLOGY,
 
 
 
111
 
  
  
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(2) G. Meckel, De duplic. monstr., p. 42.  
 
(2) G. Meckel, De duplic. monstr., p. 42.  
  
(3) Fleischnrann, in the Erlanger Abhandl., vol. i.  
+
(3) Fleischnrann, in the Erlanger Abhandl., vol. i.
 
 
 
 
==Section II. Of the Muscles of the Extremities==
 
 
 
§ 1 105. The muscles of the extremities form the greater part of these
 
sections of the body. Most of them have a more or less elongated
 
form and assume a longitudinal direction, although this is not the direction of their fibres, which go obliquely from one or more edges to the
 
tendons. Very few of them have a transverse direction or one intermediate between it and the preceding : the latter are shorter.
 
 
 
The muscles which follow the longitudinal direction flex and extend
 
the different parts of the limbs ; the transverse and the oblique separate
 
them from each other or turn them on their axes.
 
 
 
The muscles of both extremities are surrounded with general tendinous sheaths ( fascia! aponeuroticœ) and the tendons of the inferior, which
 
are the longest in proportion, and are firmly attached in several places
 
by strong fibrous ligaments to the bones over which they pass.
 
 
 
In regard to situation, arrangement, and number, they correspond
 
perfectly in their essential particulars, and differ only in modifications
 
dependent on the different functions of the two limbs.
 
 
 
 
 
CHAPTER I.
 
 
 
MUSCLES OF THE UPPER EXTREMITIES.
 
 
 
§ 1106. The muscles which move the first section of the bones of
 
the upper extremity, or the bones of the shoulder, all come from the
 
bones of the trunk, from which arise also some of those which move
 
the bone of the second section — the humerus. The former are
 
the trapezius, the rhomboidei, and the levator anguli scapulæ ; the
 
others the pectoralis major and the latissimus dorsi muscles, which
 
have already been described (§ 1001).
 
 
 
It is convenient to commence the description of these muscles by that
 
of their common aponeurotic sheath.
 
 
 
 
 
ARTICLE FIRST.
 
 
 
OF THE APONEUROTIC SHEATH OF THE UPPER LIMBS.
 
 
 
§ 1107. The muscles of the upper extremities are surrounded by a
 
tendinous envelop called the brachial aponeurosis (fascia brachialis).
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
113
 
 
 
 
 
This arises in very muscular subjects from the deltoid muscle, but
 
sometimes we do not see it except below this muscle. It is always
 
stronger on the fore-arm than on the arm. However, at the posterior
 
part of the anterior and posterior faces it is always much thicker than
 
on the other faces and strengthened by transverse and oblique fibres,
 
which cover the longitudinal fibres externally.
 
 
 
In most of its extent it envelopes the muscles externally only. However, at the lower end of the arm, in the inner angle, there is a triangular slip, the internal and external intermuscular ligament ( L . intermuscular e internum et externum ), which leaves the aponeurosis and goes forward. The external extends from the outer condyle to the upper extremity of the projecting part of the anterior angle ; the internal from
 
the inner condyle to the corresponding point of the inner angle. They
 
extend between the extensors and flexors of the fore-arm and increase
 
their surfaces of attachment.
 
 
 
Two similar but much weaker ligaments are also found in the forearm in a similar situation. They separate the flexors and the extensors,
 
both on the ulnar and radial side ; because they proceed from the
 
inner face of the aponeurosis to the posterior edge of the ulna and of
 
the radius to which they are attached.
 
 
 
Near the lower end of the fore-arm, the transverse fibres disappear,
 
or at least become evidently thinner ; but they again accumulate on
 
the end of its posterior face and on the back of the thumb, become
 
much more thick than high, and give rise in this place to the dorsal
 
ligament of the carpus ( Lig . carpi dorsale , s. armillare ).
 
 
 
This ligament extends from the transverse process of the radius to
 
the small head of the ulna, the pisiform, and the tuberosity of the fifth
 
metacarpal bones. It is formed at its upper part, which is the weakest,
 
of transverse fibres, which descend from the ulna to the radius, and at
 
the lower part of fibres, which go backward and downward from the radius, and consequently partially cross the preceding.
 
 
 
Under it pass the tendons of the abductor magnus and extensor pollicis, the radiales externi, the extensor digitorum communis, the extensor indicis proprius, the extensor minimi digiti proprius, and the
 
ulnaris externus muscles. Their passage is facilitated by the
 
partitions which descend from the inner face of the ligament to the
 
asperities on the ends of the bones of the fore-arm and divide it into six
 
parts.
 
 
 
The first, the anterior,, extends from the anterior edge of the lower
 
end of the radius to the first asperity on the back of this bone, and contains the tendons of the abductor pollicis longus and of the extensor
 
pollicis brevis muscles.
 
 
 
Through the second, which is larger and which extends from the
 
first dorsal asperity to the second, pass the tendons of the two radial©
 
externi muscles.
 
 
 
The third, a little oblique forward and downward, extends from tin
 
second to the third dorsal asperity of the radius, to the posterior edge
 
 
 
Vol. IT. 15
 
 
 
 
 
114
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
of its lower extremity, and lodges the tendon of the extensor pollids
 
longue muscle.
 
 
 
The fourth, the largest, extends from the third dorsal eminence to
 
the posterior edge of the radius, and receives the tendons of the extensor digitorum communis and extensor proprius indicis muscles.
 
 
 
The fifth, the smallest, is comprised between the radius and the
 
anterior edge of the small head of the ulna ; it receives the tendon of
 
the extensor minimi digiti proprius muscle.
 
 
 
Finally, the sixth, which extends from the posterior edge of the small
 
head of the ulna to its styloid process, embiaces the tendon of the ulnaris
 
externus muscle.
 
 
 
The lower edge of this ligament, which should be regarded not as
 
a separate ligament but only as the development of the brachial aponeurosis, is uninterruptedly continuous with the aponeurosis of the
 
back of the hand, which gives a loose common envelop to the tendons
 
of the extensor muscles, blends with the oblique tendinous fibres by
 
which the tendons of the extensors of the fingers are retained in place,
 
and concurs to form them.
 
 
 
The brachial fascia is also strengthened at the lower part of the anterior face of the fore-arm and on the palmar side of the carpus.
 
 
 
The upper part of this portion, which is the feeblest and which extends
 
from the anterior edge of the radius to the pisiform bone, forms the
 
common palmar ligament of the carpus ( Lig . carpi velar e commune).
 
It unites at its ends with the dorsal ligament. Under it pass the tendons
 
of the flexors of the fingers, and in a special sheath that of the radialis
 
internus.
 
 
 
The lower part, which is much stronger, forms the proper palmar
 
ligament of the carpus {Lig- carpi volare proprium). This ligament
 
is formed by transverse and oblique fibres. Above, it blends in great
 
part with the preceding. Below, it strengthens the palmar aponeurosis. Its two edges arise from the palmar eminences of the carpus,
 
which are formed on the radial side by the trapezium and the pyramidal
 
bones and on the ulnar side by the pisiform and unciform bones.
 
 
 
ARTICLE SECOND.
 
 
 
MUSCLES OF THE SHOULDER.
 
 
 
§ 1108. The muscles of the shoulder, which surround the scapula
 
and which extend from this bone and also from the clavicle to the humerus, are the deltoides, the supraspinatus, the infraspinatus, the teres
 
major, the subscapularis, the teres minor, and the coraco-brachialis
 
 
 
muscles.
 
 
 
I. deltoïdes, or the extensor of the arm.
 
 
 
§1109. The deltoides muscle, Sus-acromio-humeral, Ch. {M. deltoïdes , levator , attollens humeri), is a very strong muscle, which occupies
 
 
 
 
 
3IYOLOGY.
 
 
 
 
 
115
 
 
 
 
 
the upper and anterior part of the region of the shoulder. It arises by
 
its upper longest and concave edge from the anterior edge of the scapular end of the clavicle, from the anterior edge of the acromion process,
 
and from the lower edge of all the spine of the scapula at its anterior
 
part, by fibres almost entirely fleshy or which at least have very short
 
tendons, and by very long tendinous fibres at its posterior.
 
 
 
After leaving this point, the muscle gradually becomes thicker, goe3
 
downward, and terminates by a fleshy summit externally, but possessing
 
within a very long tendon, which is attached directly below the tendon
 
of the pectoralis major muscle, at the posterior end of the external linea
 
aspera, which arises from the outer tubercle of the humerus and at the
 
central part of the outer face of this bone, which presents in this place
 
a triangular impression.
 
 
 
These fibres converge from above downward ; so that the central
 
are straight, the anterior oblique from before backward, and the posterior from behind forward.
 
 
 
In examining this muscle more attentively, we recognize that it is
 
composed of two orders of triangular fasciculi. The first order contains four fasciculi, which are larger than the others and the bases of
 
which are turned upward and their summits downward. Between are
 
the three smaller fasciculi of the second order, which are broader
 
below than above but the two ends of which are a little narrower than
 
the central part.
 
 
 
Below the upper edge of this muscle, between it and the capsular
 
ligament, we find a considerable mucous bursa, which corresponds
 
usually to the acromion, extends between this last process and the
 
proper anterior ligament of the shoulder, and sometimes divides into
 
two bursæ, one of which is situated near the coracoid process.
 
 
 
The deltoid muscle raises the arm and separates it. from the side of
 
the body.
 
 
 
§ 1110. A remarkable analogy -with the structure of the mammalia
 
is the existence of a posterior slip, entirely distinct from the rest of the
 
muscle, which we have found several times. This slip arises from the
 
tendinous expansion of the infraspinatus muscle (§ 1112), and from the
 
centre of the inner edge of the scapula, by a broad and thin tendon,
 
and is attached to the tendon of the deltoides. In most mammalia, in
 
fact, the deltoides divides into a clavicular and a scapular portion and
 
the latter is subdivided into an acromial and a spinous portion.
 
 
 
We more frequently find the posterior part of the muscle simply
 
separated from the anterior. We ought also to place among these
 
anomalies the existence of a head, which goes from the anterior edge
 
of the scapula to the deltoides,(l) and which is still more analogous
 
â– with a part of the deltoides in birds.
 
 
 
 
 
(1) Albinus, p. 422.
 
 
 
 
 
116
 
 
 
 
 
t» ESi'RÏ PTT VE ANATOMY.
 
 
 
 
 
II. ROTATORS OUTWARDLY.
 
 
 
I. SUPRASPINATUS.
 
 
 
§ 1111. The supraspinatus muscle, Petit susse upvlo-trochitcriev
 
Ch., is a triangular muscle which fills the supraspinal fossa, and is
 
formed of fibres which converge from behind forward, from below
 
upward, and from within outward. At first it is rather thick, but gradually becomes thinner. It arises from all the supraspinal fossa, from
 
that part of the posterior edge of the scapula situated above the spine,
 
and from the posterior part of the upper edge and also from the upper face of this spine. It changes under the acromion process, directly
 
below the large proper ligaments of the scapula, into a short and strong
 
tendon, which, passing below the capsular ligament of the scapulo-humeral articulation, which it contributes to strengthen, goes to attach
 
itself to the upper and inner part of the outer tubercle of the humerus.
 
 
 
This muscle turns the arm outward and raises it,
 
 
 
II. INFRASPINATUS.
 
 
 
§ 1112 . The infraspinatus muscle, Grand susscapido-trochiterien ,
 
Ch., arises from all the infraspinal fossa of the scapula, except its
 
lower part. It goes outward and forward, so that its upper fibres are
 
transverse, and the lower become more oblique forward and upward the
 
lower they are. Its thickness gradually increases as it proceeds
 
outwardly and it terminates in a strong tendon, which extends farther
 
on the posterior than on the anterior face. This tendon adheres to the
 
capsular ligament of the shoulder which it strengthens, blends above
 
with that of the preceding muscle, and is attached to the central part
 
of the outer tubercle of the humerus.
 
 
 
We find a large mucous bursa between the scapula and this tendon.
 
 
 
This muscle draws the humerus backward and downward, and
 
rotates it from within outward.
 
 
 
III. TERES MINOR.
 
 
 
§ 1113. The teres minor muscle, Plus petit susscapulodrochiterien,
 
Ch. is quadrangular, and is scarcely distinguished from the preceding.
 
It arises from the central part of the posterior lip of the anterior edge
 
of the scapula, and goes directly before the lower and anterior edge of
 
the infraspinatus muscle forward, outward, and downward, where,
 
gradually becoming narrower but thicker, it terminates by a short and
 
strong tendon at the lower part of rhe outer tubercle of the humerus,
 
and at the outer ridge of the humerus which descends from this tubercle.
 
 
 
It acts like the preceding, but it draws the humerus more outward
 
 
 
MYOLOGY.
 
 
 
 
 
117
 
 
 
 
 
HI. ROTATORS INWARD.
 
 
 
SUB-SCAPÃœLARIS.
 
 
 
§ 1114. The subscapularis muscle, sous-scapulo-trochinien , Ch., the
 
strongest of the two muscles which turns the humerus on its axis
 
inward, occupies all the lower face of the scapula. Its upper fibres
 
descend obliquely outward and forward, the central are transverse, and
 
the inferior are very oblique from behind forward and from within
 
outward. It gradually contracts to a considerable degree, passes
 
behind the upper end of the coraco-brachialis, and the shoit head of
 
the biceps muscle, and terminates in a short, flat, and thick tendon,
 
which is attached to all the circumference of the inner tubercle of the
 
humerus.
 
 
 
Its structure is very complex, and we may reduce it to two orders of
 
fasciculi which are more or less evidently distinct. The first, commonly five in number, arise by a tendinous summit along the inner lip
 
of the posterior edge, and the asperities which are found on the anterior face of the scapula. The lower, which is also the strongest, forms
 
the lower and outer part of the muscle. All progressively enlarge,
 
and are attached to the upper tendon.
 
 
 
We find the second layer between them ; this also is formed of five
 
fasciculi, of which the upper likewise forms the upper part of the muscle. These fasciculi are generally stronger and broader externally,
 
and pointed inwardly. They come from the spaces between the eminences, whence the former arise.
 
 
 
These two layers however interlace more than once, and we cannot
 
insulate them without cutting their fibres. The third layer, which is
 
described in most works on anatomy, does not in fact exist.
 
 
 
This muscle has two mucous bursæ. The larger is sometimes
 
united with the capsular ligament of the scapulo-humeral articulation,
 
and is situated on the neck, and at the base of the coracoid process of
 
the scapula. The smaller, which does not always exist, is situated
 
much lower and further forward, between the capsular ligament and
 
the tendon of the muscle.
 
 
 
The subscapularis muscle draws the arm towards the trunk, turns
 
it on its axis from without inward, and depresses it when it is
 
raised. If the arm is fixed it can carry the scapula outward.
 
 
 
rr. TERES MAJOR.
 
 
 
§ 1115. The teres major muscle, Scapulo-humeral , Ch. (AÏ. teres , s.
 
rotundas major, s. déprimons hmnerum rotundas) arises from the lower
 
and triangular part of the outer face of the scapula, and from the posterior lip of the anterior edge, where it usually adheres to the subscapularis and teres minor muscles ; but it soon leaves these two muscles and
 
ascends, always much less obliquely than the teres minor, from which
 
 
 
 
 
lis
 
 
 
 
 
DESCRIPTIVE ANVTOMY.
 
 
 
 
 
it is separated by the long portion of the biceps, between the latter and
 
the coraco-brachialis, approximates the humerus, and is attached by
 
rather a short, broad, but thin tendon, to the inner rough line, directly
 
behind and a little below the latissimus dorsi.
 
 
 
Its form is the same as that of the teres minor, but it is at least twice
 
as large as that muscle.
 
 
 
We find below and forward, between its tendon, the latissimus dorsi
 
muscle, and the humerus, a small mucous bursa, and beside these, we
 
also find one or more in its anterior tendon where it divides.
 
 
 
This muscle draws the humerus backward, downward, and inward ;
 
when the arm is turned outward, it brings it a little inward.
 
 
 
§ 1116. It is often united with the posterior part of the latissimus
 
dorsi muscle by a large fasciculus which leaves its posterior extremity.
 
 
 
IV. COKACO BHACHIALIS.
 
 
 
§ 1117. The coraco-brachialis muscle, Coraco-humeral , Ch. (M.
 
coraco-brachialis , s. coracoideus , s. perforatus Casserii) is formed like
 
an oblong triangle. United above, rather intimately, and to some
 
extent, to the origin of the short portion of the biceps flexor muscle
 
(§ 1120), it arises from the coracoid process farther forward than the
 
latter. It, is tendinous before, in most of its length, and fleshy behind.
 
In quitting the short portion of the biceps muscle it goes inward,
 
becomes thicker at its central part, but contracts much at its lower
 
end, and is attached, partly fleshy, partly tendinous, to the middle
 
region of the inner face of the humerus.
 
 
 
The musculo-culaneous nerve generally perforates it in its centre.
 
Its lower part often blends with the upper end of the brachialis internus
 
muscle, a curious fact, as it adds a new feature to the analogy between
 
the flexors of the fore-arm and those of the leg. We find one imperfect bursa, and sometimes two, between its upper tendon, that of the
 
short portion of the biceps muscle, and the capsular ligament of the
 
scapulo-humeral articulation.
 
 
 
This muscle approximates the humerus and the scapula to each
 
other, carries the arm to the side of the bodjq and rolls it a little outward, when it is turned inward.
 
 
 
Sometimes, instead of a simple perforation, it presents a real fissure,
 
which is often confined to its lower part, and sometimes exists its
 
whole length, so that the tendons are separated although the musculocutaneous nerve passes constantly between the two portions. This
 
arrangement establishes a striking similarity with the structure of the
 
apes.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
119
 
 
 
 
 
ARTICLE THIRD.
 
 
 
MUSCLES OF THE ARM.
 
 
 
§ 1118. The muscles found on the humerus arise partly from this
 
hone, others from the scapula, axrd are attached to the bones of the
 
fore-arm. Theyare the triceps extensor, the biceps flexor, and the brachialis intemus ; the first is situated at the posterior and outer part of the
 
arm ; the other two are placed on its anterior and inner face.
 
 
 
 
 
I. TRICEPS EXTENSOR,
 
 
 
§ 1119. The triceps extensor muscle, Scapulo-olecranien , Ch. (JVI.
 
triceps brachii , cubiti , s. brachieus externus , s. posterior) occupies most
 
of the posterior face of the humerus, and extends from the scapula to
 
the olecranon process.
 
 
 
The long or the posterior head ( caput longum, cmconœus longus)
 
arises. by a short, flat, and thick tendon, directly before the anterior
 
insertion of the teres minor muscle, from the upper end of the anterior
 
edge of the scapula, and goes from above downward, gradually increasing in thickness. The tendon descends very low on its inner face. Its
 
lower tendon extends in all its lower half along the inner part of its
 
inner face, and the fleshy fibres are inserted in it obliquely. Its form
 
is elongated.
 
 
 
The large head, or the outer head, ( caput externum, s. magnum, unconcern magnus, s. externus) arises above by a thin extremity which
 
terminates by a convex edge, and presents very short tendinous fibres.
 
This end is attached, directly below the insertion of the teres minor
 
muscle, at the upper part of the posterior face of the humerus. The
 
fleshy fibres come also from all the anterior edge of the bone. This
 
head descends as far as the outer condyle, by a short tendon, which is
 
oblique from above downward, from before backward, and from without inward, unites backward and inward to the lower tendon of the
 
long head. In all its lower portion its inner and posterior pari is
 
covered by the common lower tendon of the brachialis internus muscle
 
Its form is that of an elongated rhomboid, its breadth exceeds its thickness.
 
 
 
The short or internal head arises, directly below the upper extremity
 
of the preceding, from most of the posterior face of the humerus, and
 
descends along the inner edge of the bone to near the inner condyle,
 
rests, by its posterior and inner edge, upon the tendons of the teres
 
major and coraco-brachialis muscles, and also the inner edge of the
 
brachialis internus. Its fibres go obliquely downward and outward ;
 
they are attached to the lower tendon of the long head in all the lower
 
part of the short head.
 
 
 
 
 
120
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
The common lower tendon of these three heads, which covers them
 
outwardly at their lower part, is not destitute of fleshy fibres except in
 
a very small portion of its extent below, and is inserted in the upper
 
broad edge of the posterior face of the olecranon process of the ulna.
 
 
 
We find a considerable mucous bursa between this tendon and the
 
olecranon process, besides which we sometimes find two smaller ones
 
on each side. We less commonly see another, also smaller, above.
 
 
 
This muscle extends the articulation of the elbow and usually moves
 
the fore-arm ; but it can also move the arm when the fore-arm is fixed.
 
The long head brings the scapula towards the humerus, and draws
 
the latter inward and backward.
 
 
 
 
 
II. BICEPS FLEXOR.
 
 
 
§ 1120. The biceps flexor muscle, Scapulo-radial , Ch. ( flexor
 
antibrachii biceps, s. radialis, s. biceps internus ), is a very long muscle,
 
situated on the anterior and the outside of the arm, and extends its
 
whole length. Its two heads are separated above in almost all the
 
muscle, and extend from the scapula, whence they arise, to the upper
 
extremity of the radius.
 
 
 
The internal, posterior, or short head ( caput breve), called also the
 
coraco-brachialis muscle, from one of its attachments, is not only shorter
 
but also thinner than the long head. It arises from the coracoid process by a short, flat, and narrow tendon, which it has in common with
 
the coraco-brachialis muscle, more forward and outward than the latter,
 
proceeds on its outside a little obliquely from within outward, covers
 
below the inner and upper part of the brachialis internus muscle, and
 
lower down becomes a tendon, which is first seen on its external face,
 
on the side corresponding to the long head. This tendon, which unites
 
to that of the last, is attached to the tuberosity of the radius.
 
 
 
Tire long head ( caput longum , s. M. glcno-radialis ) arises by a long,
 
thin, and flat tendon from the centre of the upper part of the edge of the
 
glenoid cavity of the scapula. This tendon is inclosed in a special
 
fold of the capside of the scapulo-humeral articulation, which answers
 
as a mucous sheath, passes upon the head of the humerus, and is situated in the groove between the two tuberosities of this bone, where it
 
is retained by the fibres of the fibrous ligament of the shoulder-joint,
 
and on the anterior extremity of which the mucous sheath ceases. It
 
thus comes to the anterior and outer side of the arm, where it soon continues with its fleshy belly but deeper than the tendon of the short head.
 
This latter descends above, along the anterior and external edge of the
 
triceps extensor muscle ; below, before the central part of yhe brachiahs internus muscle : at its lower extremity it is attached on one
 
side, that is by its internal face, to the tendon of the short head ; on
 
the other to a peculiar tendon contained within it, and which when entirely destitute of fleshy fibres is united with that of the first head, being inserted at the same place with it.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
121
 
 
 
 
 
We find a large mucous bursa between the lower tendon, that of the
 
supinator brevis and the tuberosity of the radius, to which sometimes a
 
smaller is added, situated on the outer face of the tendon.
 
 
 
The principal use of this muscle is to flex the articulation of the
 
elbow. It also turns the fore-arm backward, contributes to draw it
 
inward when it is extended, and depresses the scapula toward the
 
humerus.
 
 
 
§ 1121. The biceps flexor muscle is one of those muscles most
 
subject to variation, and presents the most singular anomalies.
 
 
 
The least considerable anomaly is where the two heads arise much
 
lower than usual, so that they are only united by the inferior tendon.(l)
 
 
 
A greater anomaly, which is not rare, is when a third head exists,
 
which is usually smaller than the other two and which arises near the
 
centre of the internal face of the humerus, (2) more rarely from only
 
the brachialis internus muscle, (3) although it is often blended with it.
 
Sometimes also it is united with the coraco-brachialis muscle. This anomaly is very remarkable, as it is a repetition of the small head, which
 
properly belongs to the biceps femoris muscle, and because its union
 
with the coraco-brachialis muscle makes the number of the long flexors
 
of the fore-arm equal to those of the long flexors of the leg. At the
 
same time it approximates man to animals ; since in birds the long
 
flexor of the fore-arm presents a second smaller head, which arises from
 
the lower tuberosity of the humerus ; while in apes the brachialis
 
internus muscle extends much higher.
 
 
 
The number of heads of this muscle sometimes increases still more,
 
so that we number five ; but these are not inserted in one common
 
inferior tendon. (4) At the side of the third which is most usually met
 
with we sometimes find a fourth, and along the tendon of the short head
 
a fifth, which unite and are attached to the radius below the usual
 
tendon ; in this case, consequently, there were in fact three flexors, as
 
is always found in birds.
 
 
 
III. BRACHIALIS INTERNUS.
 
 
 
§ 1122. The brachialis internus muscle, Humero-cubital, Ch. (AT.
 
flexor cubitalis ulnaris , s. brachieus intermis ), a broader and thicker
 
muscle, especially at its posterior part, which entirely covers the inferior portion of the internal and anterior faces of the humerus, arises by
 
an external and an internal slip, the former being higher, from the external and internal faces of the humerus above its centre. These
 
two slips surround the lower extremity of the deltoides muscle ; the
 
internal extends to the coraco-brachialis and the external to the upper
 
 
 
(1) Weitbrecht, Comment. Petrop., 1731. — Albinus, loc.cit. — Rudolphi, in Gant~er,
 
6. — We have seen it several times but always on one side.
 
 
 
(2) Albinus, loc. cit., p. 43S, 439. — Mayer, loc. cit.
 
 
 
(3) Kelch, loc. cit., p. 35.
 
 
 
(4) Pietsch, in Roux Journal de Med., vol. xxxi. p. 245.
 
 
 
Vol.II. 16 •
 
 
 
 
 
122
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
extremity of the large head of the triceps extensor muscle. Its anterior edge descends along the external edge of the humerus, and the
 
posterior along the internal edge of this bone to the part where it suddenly enlarges.
 
 
 
Its fibres are attached to a strong rounded inferior tendon, which reascends on the anterior face of the muscle almost to its centre. This
 
tendon is inserted in the tuberosity of the ulna.
 
 
 
Between the tendon of the brachialis internus, that of the biceps
 
flexor cubiti, the supinator brevis muscle, and the capsular ligament,
 
we find a mucous bursa, which is not however constant.
 
 
 
This muscle flexes the articulation of the elbow.
 
 
 
§ 1123. We sometimes find at the side of it, but more forward and
 
outward, a second brachialis internus muscle, which is smaller and
 
which is an exact repetition of it as respects its attachments, the inferior
 
tendon of which is inserted deeper than that of the other, and which
 
even presents a rudiment of the preceding muscle, which we said belonged to birds. The first degree of this anomaly is the separation of
 
the posterior from the anterior part of the muscle, which not unfrequently occurs. This division of the brachialis internus muscle into
 
two parts is also worthy of remark, as it assimilates this muscle to the
 
flexors of the leg. Its abnormal union with the biceps flexor by a muscular slip (§ 1121) is on the contrary the first index of the formation of
 
a third head to the latter (§ 1121).
 
 
 
The anomalies of the brachialis internus, the biceps flexor, and the
 
coraco-brachialis muscles (§ 1116), considered collectively, seem to be
 
so many efforts by which nature endeavors to establish a perfect resemblance between the upper and lower extremities. They are generally
 
found singly ; but if we suppose them united, we have an arrangement
 
perfectly similar to that of the lower extremities.
 
 
 
The coraco-brachialis and brachialis internus muscles, divided into
 
two portions and often united with each other, evidently represent the
 
semimembranosus and the semitendinosus muscles. The muscular band
 
which goes from the brachialis internus to the lower part of the biceps
 
flexor muscle, united with the unusually deep division of the latter, may
 
be considered as tending to insulate the two heads and to form a second
 
flexor of the ulna, even as the tibia is flexed by two distinct muscles.
 
 
 
 
 
ARTICLE FOURTH.
 
 
 
MUSCLES OF THE FORE-ARM.
 
 
 
§ 1124. The muscular mass of the fore-arm is formed of those muscles which move the bones upon each other or on the humerus, by the
 
muscles which act on the carpus, and by the long muscles of the fingers.
 
 
 
The motions of the bones of the fore-arm on each other, or pronation
 
and supination, are performed by four muscles, the supinator longus
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
123
 
 
 
 
 
and the supinator brevis, the pronator teres and the pronator quadratus,
 
all of which except the first are situated deeper than the other muscles
 
of the fore-arm.
 
 
 
The two bones of the fore-arm are moved on the humerus by one
 
muscle, the anconeus.
 
 
 
Five muscles move the carpus ; the extensor carpi radialis longus
 
and the extensor carpi radialis brevis extend it ; it is flexed by the
 
flexor carpi ulnaris and the flexor carpi radialis muscles ; the extensor
 
carpi ulnaris draws it backward.
 
 
 
The fingers are extended by the extensor digitorum communis, the
 
extensor pollicis longus and brevis, the extensor indicis proprius, and the
 
extensor minimi digit i proprius ; they are flexed by the flexor sublimis,
 
the flexor profundus, and the flexor pollicis longus.
 
 
 
These different muscles succeed each other in the following order,
 
when we commence their description at the radial edge and follow
 
the external face of the fore-arm to the ulnar edge and return from this
 
to the radial edge along the internal face of the arm.
 
 
 
I. MUSCLES OF THE INTERNAL FACE OF THE FORE-ARM.
 
 
 
I. SUPINATOR LONGUS.
 
 
 
§ 1 1 25. The supinator longus muscle, Humero-sus-radial , Ch.,is a long
 
muscle, which arises by short tendinous fibres from the inferior part of the
 
anterior edge of the humerus, where it unites with the large head of the
 
triceps extensor muscle. It goes downward and passes on the inferior
 
and external part of the brachialis internus, which it covers, and
 
reaches the fore-arm along and before the inferior extremity of this
 
muscle ; it goes on the radial edge of the fore-arm and is changed high
 
up into a long and thin tendon, which covers above only the internal
 
face, and is finally attached to the anterior face of the internal edge of
 
the radius, a short distance above its inferior face. It turns the radius
 
backward and inward, consequently carries the hand to the state of
 
supination, and flexes the fore-arm.
 
 
 
II. EXTENSOR CARPI RADIALIS LONGUS.
 
 
 
§ 1126. The extensor carpi radialis longus muscle, Humero-susmetacarpien , Ch., resembles the preceding and appears at first view to
 
be a part of it. It arises from the lowest part of the outer edge of the
 
humerus, descends to the outer condyle, passes on the outer part of the
 
articular edge of the humerus, and on the head of the radius ; in its
 
course it becomes first thicker, afterward narrower, and terminates at
 
the same place as the preceding in a tendon, at first rather broad, flattened, and loose to a much greater distance, which descends in the same
 
direction along the radius and enters below into the anterior groove of
 
the outer face of the lower extremity of the radius under the posterior
 
ligament of the carpus, thus arrives at the carpus and is attached to
 
 
 
 
 
124
 
 
 
 
 
DESCRIPTIVE ANATOMY
 
 
 
 
 
the anterior part of the posterior face of the base of the second metacarpal bone.
 
 
 
The lower tendon is surrounded with a mucous sheath where it
 
passes over the lower extremity of the radius. We also find a small
 
bursa at its insertion in the root of the second metacarpal bone.
 
 
 
This muscle extends the hand and draws it a little toward the radial
 
side of the fore-arm ; it also serves to execute the motion of pronation
 
toa certain extent and flexes the articulation of the elbow.
 
 
 
§ 1127. Sometimes a smaller and feebler muscle is detached from
 
its lower edge, which succeeds the extensor carpi radialis brevis muscle and is attached a little above it to the root of the third metacarpal
 
bone.(l)
 
 
 
III. EXTENSOR CARPI RADIALIS BREVIS.
 
 
 
§1128. The extensor carpi radialis brevis muscle, Epicondylo-susmétacarpien , Ch., is very similar to the preceding, but is smaller. Its
 
upper tendon, which is very strong, exists nearly the whole length of
 
its posterior face. It arises from the anterior face of the outer condyle
 
of the humerus, and is attached, below the middle of the fore-arm, by
 
an elongated, flat, but narrow tendon, the upper part of which covers the
 
lower part of the outside of the muscle. This tendon is inserted in the
 
outer face of the base of the third metacarpal bone, and slightly also
 
in that of the second. There is a small bursa between it and the third
 
metacarpal bone.
 
 
 
This muscle acts in the same manner as the preceding.
 
 
 
§ 1129. It is sometimes entirely deficient, (2) as in several mammalia,
 
where we never find but one extensor radialis muscle : the first degree
 
of this formation is the complete union of the second radialis muscle, of
 
which several instances are known. Sometimes its tendon divides into
 
two slips, which are attached to the third metacarpal bone only, or one
 
is inserted into this bone, and the other into the next ; even as in the
 
mammalia, which have only one radialis muscle, the tendon divides
 
into two slips.
 
 
 
Besides the bursæ already mentioned, the tendons of the two muscles
 
are surrounded by two common sheaths, the upper of which is situated
 
above the lower end of the radius, while the lower is placed at a short
 
distance from it on this extremity, and on the upper range of the carpal
 
bones.
 
 
 
 
 
IV. EXTENSOR DIGITOnUM COMMUNIS.
 
 
 
§ 1130. The extensor digitorum communis muscle, Epicondylo-sttsphalangettien commun , Ch., commences by a strong tendon, which
 
 
 
(1) Albinus, Inc. cit., p. 448.
 
 
 
(2) J. G. Salzmann, Diss. sist. rdurium pedis musculorum defectum, Strasburg',
 
1734, p. 11.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
125
 
 
 
 
 
extends on the upper part of the external face of its belly. It arises
 
from the lower and back part of the outer condyle of the humerus,
 
directly under and behind the radialis externus brevis muscle, with
 
which it is intimately connected for several inches. Near the centre
 
of the fore-arm it separates into three bellies, the posterior of which
 
also divides a little farther in two others, so that the whole number of
 
these bellies is four ; these are inserted into as many elongated and
 
flat tendons, of which the second is usually the strongest, the third
 
smaller than the first, and the fourth is the weakest.
 
 
 
All these tendons pass under the posterior ligament of the carpus,
 
between it and the outer face of the lower end of the radius. They
 
become broader and thinner on the back of the hand, partially separate,
 
especially near the anterior end of the metacarpus, and are again united
 
by strong oblique intermediate tendons of various breadths. They go
 
to the second, third, fourth and fifth fingers, and contract on the articulation of the metacarpus with the phalanges ; but in this place they
 
give off on each side fibres, which go downward ; farther on they
 
again enlarge, and are blended on each side with the tendons of tho
 
interosseous muscles. On the first joint of the phalanges they divide
 
into a central and two lateral portions, which are much longer ; the
 
central tendon, having strengthened the dorsal face of the capsular
 
ligament, is attached to the upper edge of the base of the second phalanx ; the other two are united forward, and are inserted in the upper
 
part of the back of the third phalanx.
 
 
 
At the lower end of the fore-arm, of the carpus and metacarpus, the
 
tendons of this muscle have a mucous sheath, which is single above,
 
but divides on the carpus into three branches, each of which goes with
 
its tendon to the base of the first phalanx.
 
 
 
This muscle extends the second, third, fourth, and usually the fifth
 
finger also.
 
 
 
§ 1131. Sometimes its three bellies are separated high up, and even at
 
their origin. ( 1 ) Sometimes it divides into four tendons ; the fourth goes
 
to the little finger, and unites to its proper extensor. This fourth tendon
 
sometimes divides on the back of the hand into two parts ; the outer
 
joins the tendon of the extensor minimi digiti proprius muscle, and the
 
inner again divides into two portions, one of which unites to the tendon
 
of the fourth finger, and the other to that of the fifth. (2) In some subjects the third and fourth tendons go to the third finger. In this case
 
the muscle itself often divides into two bellies, each of which has two
 
tendons. (3)
 
 
 
These divisions of the fleshy part of the muscle are curious, being
 
similar in one respect to the extensors of the toes and also to the flexors
 
of the fingers, which are both double.
 
 
 
(1) Albinus, loc. cit., p. 452. — Brugnone, loc. cit., p. 167.
 
 
 
(2) Albinus, loc. cit.
 
 
 
(3) Brugnone, loc. cit.
 
 
 
 
 
126
 
 
 
 
 
DESCRIPTIVE ANATOMV.
 
 
 
 
 
V. EXTENSOR MINIMI DIGITI PROPRIUS.
 
 
 
§ 1132. The extensor minimi digiti proprius muscle, Epicoudytosus-phalangetlien du petit doigt , Ch., is slender, elongated, and thin.
 
It arises bj two tendinous heads from the outer part of the head of the
 
radius, from the part of the capsular ligament surrounding this head,
 
and from the upper end of the anterior edge of the ulna. It descends
 
behind the preceding, with which it is closely united for some distance,
 
and near the lower end of the fore-arm becomes a thin tendon, which
 
passes below the posterior ligament of the carpus in a special groove,
 
enlarges along the metacarpal bone of the fifth finger, unites inward with
 
the fourth tendon of the preceding muscle, and is attached to the upper
 
face of the head of the third phalanx of the little finger.
 
 
 
Its tendon is surrounded from the lower part of the fore-arm to the
 
centre of the fifth metacarpal bone by a sheath, which is single above,
 
but below divides like the tendon into two parts.
 
 
 
This muscle extends the little finger.
 
 
 
§ 1133. It is sometimes deficient, (1) and then it is generally
 
replaced by a tendon of the extensor digitorum communis muscle. In
 
other cases, on the contrary, its tendon divides into two slips, one of
 
which goes to the fourth finger, an arrangement worthy of remark
 
because of its analogy with several mammalia.
 
 
 
VI. EXTENSOR CARPI ULNARIS.
 
 
 
§ 1134. The extensor carpi ulnaris muscle, Cubito-sus-metacarpien,
 
Ch. (M. ulnaris externus , s. extensor manus ulnaris ), arises by two tendinous slips, of which the smaller and shorter is situated at the side of
 
the extensor digitorum communis, and comes from the posterior and
 
lower part of the external condyle of the humerus, and the longer
 
arises from the upper part of the anterior face of the tubercle of the
 
ulna. These two. slips soon unite in a considerable belly. The latter
 
is tendinous at its inner and outer faces, and adheres in a considerable
 
extent to the extensor proprius minimi digiti muscle, descends along
 
the outer face of the ulna, from which it receives some fibres, and becomes, near the lower third of the fore-arm, a strong tendon, which,
 
passing across a particular portion of the dorsal ligament of the carpus,
 
comes on the back of the hand, where it is attached to the tubercle of
 
the metacarpal bone of the fifth finger. There is but one mucous
 
bursa between its upper extremity and the head of the radius.
 
 
 
This muscle extends the hand and draws it backward toward the
 
posterior edge of the fore -arm.
 
 
 
§ 1135. A tendon of greater or less extent is often detached to go to
 
the fifth finger, and at the base of the first phalanx unites with that of
 
its proper extensor.
 
 
 
(1) Brugnone, p. 167. — Wc have known two instances where it was deficient.
 
 
 
 
 
MYOLOGY,
 
 
 
 
 
127
 
 
 
 
 
VII. ANCONÅ’US.
 
 
 
§ 1136. The anconœus muscle, Epicondylo-cubiial, Ch. (J\I. anconœus , s. anconœus quartus), is a triangular muscle and mostly covered
 
by the upper extremity of the preceding ; it arises by a short and strong
 
tendon from the i nner part of the outer condyle of the humerus, descends
 
toward the ulna, and is attached by a broad fleshy surface to the
 
upper part of the anterior face of this bone. Its upper straight edge
 
usually blends with the outer belly of the triceps extensor muscle.
 
 
 
This muscle extends the fore-arm, also turns the radius backward,
 
so that it assists in supination.
 
 
 
VIII. SUPINATOR BREVIS.
 
 
 
§ 1137 . The supinator brevis muscle, Epicondylo-radia! , Ch., is triangular ; its base looks upward, and its apex downward. It arises
 
from the upper part of the anterior face of the ulna, and is tendinous
 
outwardly and fleshy inwardly. Its upper fibres are transverse and
 
the lower oblique. It goes downward and forward, turns on the upper
 
part of the radius, and is attached by a broad fleshy edge to the anterior part of the capsule of the ulna, and also to the upper part of the
 
anterior and inner faces of the radius as far as its posterior edge. It
 
turns the hand and the radius on their axes backward and outward.
 
 
 
§ 1138. The upper part of this muscle often separates from the
 
lower sooner than usual, and differs from it in the direction of its fibres,
 
is separated from it by the radial nerve, and is attached to the radius
 
without being connected with it. This anomaly leads to that in which
 
two small supinator muscles exist ; the upper extending from the
 
outer condyle of the- humerus to the anterior edge of the upper end of
 
the radius, while the internal goes from the head of the radius to its
 
centre. (1) Probably the second variety may be considered as an
 
index of the formation peculiar to apes, in which three supinators
 
exist. (2)
 
 
 
 
 
IX. ABDUCTOR POLLICIS LONGUS.
 
 
 
§ 1139 . The abductor pollicis longus muscle, Cubito-sus-métacarpien du pouce , Ch., is a considerable muscle inserted, by very short
 
tendinous fibres, directly below the anconeus and the supinator brevis, to
 
the second fifth of the anterior edge of the ulna, to the outer face of the
 
interosseous ligament, and to the central part of the outer face of the
 
radius. It descends along the last, passes below on the anterior face of
 
the radius, and there becomes a strong tendon, which passes through
 
a particular division of the dorsal ligament of the carpus. This tendon
 
 
 
(1) Sandifort, Hist. muse. p. 93. — Brugnone, loc.cit. p. 163.
 
 
 
(2) We have found at least in the Simia apella two long- supinators, situated at the
 
side of each other.
 
 
 
 
 
128
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
generally divides into two or three slips : the strongest, which is also
 
the most anterior, is attached to the radial edge of the base of the first
 
metacarpal bone ; the other two blend with the posterior extremity of
 
the antagonist muscle of the thumb.
 
 
 
The tendon near its upper extremity is surrounded by a large, oblong,
 
and rounded mucous sheath.
 
 
 
This muscle separates the thumb from the fingers, and moves it
 
toward the radius.
 
 
 
§ 1140. It is often more or less divided into two bellies, each of
 
which terminates by a tendon, and the lower is usually larger than the
 
upper. The tendons of these two bellies are often divided, and sometimes unite ; sometimes they are attached to the first bone of the metacarpus and to the trapezium.(l)
 
 
 
We more rarely find a digastric abductor of the thumb, which arises
 
from the outer condyle of the humerus, and is inserted into the base of
 
the first phalanx of the thumb.
 
 
 
X. EXTENSOR POLLICIS BREVIS.
 
 
 
§ 1141. The extensor pollicis brevis muscle, Cubito-sus-phalangien
 
du pouce , Ch., is a very small muscle, situated below the preceding,
 
and adheres intimately to its inferior edge. It arises from the outer
 
face of the interosseous ligament and from the radius, and becomes a
 
very thin tendon, which passes through the dorsal ligament of the
 
carpus in the same groove with the abductor pollicis longus, then goes
 
on the back of its metacarpal bone, becomes broader, and is attached
 
to the centre of the upper edge of the base of its fjrst phalanx.
 
 
 
This muscle extends the thumb, and at the same time removes it
 
from the other fingers.
 
 
 
§ 1 142. A small tendon sometimes arises from the anterior extremity
 
of its tendon, which blends with that of the next muscle.
 
 
 
Sometimes this muscle does not exist as a distinct muscle, and forms
 
only the lower part of the abductor pollicis longus muscle.
 
 
 
XI. EXTENSOR POLLICIS LONGUS.
 
 
 
§ 1143. The extensor pollicis longus muscle, Cubito-sus-phalangettien du pouce , Ch. (J\I. extensor pollicis major s. longus ), is much
 
stronger than the preceding, and covers its upper part ; it arises, a little
 
below the abductor magnus, and directly below its upper extremity,
 
above from the outer face and below from the anterior edge of the
 
ulna, and from the adjacent part of the external face of the interosseous
 
ligament. It soon becomes a long tendon, which passes through the
 
second groove of the dorsal ligament of the carpus, goes forward at the
 
side of the preceding, but much more inwardly, partially covers it, and
 
 
 
 
 
(1) Fleischmann, in the Erlanger Abhand ., vol. i. p. 28.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
129
 
 
 
 
 
is attached to the base of the second phalanx of the thumb, in the same
 
manner as the tendon of the extensor digitorum communis is ; but it
 
does not divide.
 
 
 
Its tendon has two mucous sheaths : the upper and larger is situated at the lower part of the fore-arm, and extends to the carpus ; the
 
inferior is smaller, and is placed on the carpus and on the base of the
 
first metacarpal bone.
 
 
 
It extends the thumb, and brings it a little towards the other fingers.
 
 
 
§ 1144. Sometimes it is completely double.
 
 
 
XII. EXTENSOR INDICIS PROPRIUS.
 
 
 
§ 1145. The extensor proprius indicis muscle, Cubilo-sus-phalangettien de l'index , Ch. (JVf. indicator , s. indie atorius, s. indicis extensor , s.
 
abductor ), is nearly as large as the preceding. It arises directly below
 
it by two slips from the third quarter of the anterior face of the ulna,
 
and near the lower part of the fore-arm becomes a strong tendon,
 
which, covered by that of the extensor digitorum communis, passes
 
with it through the third division of the dorsal ligament of the carpus,
 
below the tendinous band which goes from the latter muscle to the
 
indicator finger ; it proceeds more inwardly than this band, and is
 
attached to the base of the first phalanx of the finger, blending with it.
 
 
 
It extends the indicator finger, and approximates it a little towards
 
the third.
 
 
 
§ 1146. Sometimes it is digastric, and interrupted in its course by a
 
long tendon.(l)
 
 
 
This muscle presents several anomalies which are exceedingly
 
interesting : they consist in its more or less perfect multiplication and
 
in the formation of the extensor pollicis tertii proprius.
 
 
 
The lowest degree of this anomaly is the division of its portion into
 
two slips both of which go to the second finger, (2) or the division of
 
its belly into two parts, the tendons of which unite before arriving at
 
this finger, (3) or finally the existence of two bellies of the usual size,
 
which are entirely distinct., and of which one arises from the radius. (4)
 
 
 
The most complete anomaly is when one of the slips of the tendon
 
does not go to the indicator, but to the middle finger. (5)
 
 
 
Sometimes a small and perfectly distinct muscle arises from the
 
lower part of the outer face of the radius and from the dorsal ligament
 
of the carpus, and is attached to the first phalanx of the indicator. (6)
 
This variety is only a more perfect development of the case in which
 
the muscle arises by two heads.
 
 
 
Next comes the anomaly where we find a proper extensor of the
 
middle finger ; this muscle is always smaller than the extensor indicis
 
 
 
(1) Rosenmüller, loc. cit., p. 6.
 
 
 
(2) We have seen it several times.
 
 
 
(3) Albinus, p. 45S. — Heymann, p. 13.
 
 
 
(4) Gantzer, p. 14.
 
 
 
(5) Albinus, p. 468. — Peitsch, Syllogc obs. anat.
 
 
 
(6) Albinus, Ann, acad.. vol. iv. ch. vi.— Hevmann, p. 12.
 
 
 
Vol. II. 17
 
 
 
 
 
130
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
proprius, and arises more or less below and under it. This formation
 
varies the least possible from the normal state when the new muscle
 
comes from the ulna;(l) but sometimes it arises from the radius(2)
 
or from the dorsal ligament of the carpus. (3)
 
 
 
The greatest anomaly is where we find, beside the extensor indicia
 
proprius, an extensor for the middle finger, which divides into two tendons, one of which is attached to the metacarpal bone of the index
 
finger, and the other to that of the middle finger.
 
 
 
Finally, we have seen in one case a small tendon, which extended
 
from this proper extensor of the middle finger to the base of the first
 
phalanx of the index finger.
 
 
 
All these anomalies are curious in two respects : 1st, as a repetition
 
of the normal formation of the lower extremities, since they represent
 
the extensor communis digitorum brevis, and that more perfectly as the
 
supernumerary muscles arise lower ; 2d, as analogous with animals ;
 
for in many apes the tendon of the extensor indicis proprius furnishes a
 
slip to the middle finger, and in others, for instance in the simia apella,
 
we find a proper extensor of the index finger. (4)
 
 
 
II. MUSCLES OF THE INTERNAL FACE OF THE FORE-ARM.
 
 
 
I. palmaris Longus and brevis and the palmar aponeurosis.
 
 
 
§ 1147. The palmaris longus muscle, Epitrocldo-palmaire , Ch.,
 
is a thin oblong muscle, which arises, directly below the preceding and
 
farther back than it, from the upper part of the anterior face of the
 
inner condyle of the humerus. It goes directly forward and downward,
 
and becomes in the middle of the fore-arm a broad and thin tendon,
 
which is very near the skin. This tendon however is covered by the
 
anti-brachial aponeurosis in most of its length, and passes over this
 
aponeurosis only at its lower part. At its lower end, it divides into
 
two fasciculi : the anterior, which is shorter, and which is attached to
 
the posterior end of the abductor pollicis ; and the posterior, which is
 
much larger, and is called the palmar aponeurosis ( aponeurosis palmaris). This aponeurosis is thinner than the tendon, but much
 
broader and triangular. It gradually enlarges from behind forward,
 
so that it corresponds by its anterior edge to the four fingers. It however becomes thin, and its fibres occasionally have intervals between
 
them.
 
 
 
It is composed essentially of longitudinal fibres, like the tendon of
 
which it is the expansion. Its anterior edge is however formed of
 
transverse fibres, which are arranged over the preceding.
 
 
 
It covers most of the muscles of the palm of the hand, except those
 
of the thumb and the little finger.
 
 
 
(1) We have seen it several times.
 
 
 
(2) We have seen it once.
 
 
 
(3) Brugrione, loc. cit., p. 168.
 
 
 
(4) Meckel, Bey trage zur vergleiehéndeji anatomie, vol. ii. p. 11.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
131
 
 
 
 
 
The palmaria brevis muscle, which is composed of transverse fibres,
 
is attached to its internal edge at its upper part. This muscle, the
 
internal edge of which comes from the skin, serves to tense the aponeurosis outwardly.
 
 
 
§ 1148. The palmaris longus muscle is often deficient ; sometimes
 
it is replaced by a tendon of the flexor digitorum sublimis.(l ) In other
 
cases, on the contrary, it is unusually developed in fact thinner, but very
 
broad, and descends almost into the palm of the hand. (2) This rudiment of a peculiar muscle, which sometimes extends from the coronoid
 
process of the ulna to the palmar ligament of the carpus, is worthy of
 
remark, especially as it forms an analogy with apes. (3)
 
 
 
 
 
II. RADIALIS INTERNUS.
 
 
 
§ 1149. The radialis internus muscle, Epitrochlo-metacarpien , Ch.
 
(JVT. radial is internus, s. flexor manus radialis), is much larger than
 
the preceding, and is blended above with it, and on both sides with the
 
pronator-teres and the flexor communis digitorum sublimis ; it comes
 
from the anterior face of the inner condyle of the humerus, and sometimes also by a small head from the radius. It is partly covered by
 
the preceding and goes downward and a little forward, and near the
 
middle of the fore-arm becomes a broad tendon. This tendon passes
 
under the palmar ligament of the carpus in a special canal, formed by
 
the palmar ligament, and by the os trapezium ; it is harder and thicker
 
in this place than in other parts. After leaving this canal it becomes
 
thinner but broader, and is attached partly to the os trapezium, but
 
more particularly to the inner face of the second metacarpal bone.
 
 
 
We find a mucous bursa between the lower end of the tendon, the
 
os trapezium, and the proper palmar ligament.
 
 
 
This muscle flexes the hand and carries it a little forward.
 
 
 
III. PRONATOR TERES.
 
 
 
§ 1150. The pronator teres muscle, Epitrochlo-radial, Ch., a shorter
 
but stronger muscle, arises by very short tendinous fibres from the
 
upper edge and the upper part of the anterior face of the inner condyle
 
of the humerus. It swells a little below its origin, goes obliquely
 
downward and forward, and is covered at its lower part and at its upper
 
edge by a strong tendinous expansion, and is attached by means of
 
this, below the supinator brevis, and before the abductor pollrcis longus,
 
to the anterior face and outer edge of the radius, a little above its centre.
 
 
 
It turns the radius and also the hand inward, forward, and downward.
 
 
 
(1) Rosenmüller p. 6.
 
 
 
(2) Albinas, p. 474.
 
 
 
(3) Perrault, Mem. in Valentin i Theatr. zoot. p. 151. — Virq. ü’Azyr., Eveycl,
 
meth., sect.anat., vol. ii. p. 25, 257.
 
 
 
 
 
132
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
§ 1151. It is sometimes double. In this case the supernumerary
 
muscle extends from the posterior edge of the ulna to the posterior edge
 
of the normal muscle, which is an analogy with apes.
 
 
 
IV. FLEXOR ULNARIS.
 
 
 
§ 1152. The flexor ulnaris muscle, Cubito-carpien , Ch. (JVT. ulnaris
 
internus, s. flexor ulnaris), arises by two rather short heads, of which
 
the upper comes from the lower part of the inner face of the inner condyle of the humerus, and the posterior or the inferior from the inner face
 
of the olecranon process of the ulna. It descends along the ulna, from
 
which it is always separated by the flexor digitorum communis, and becomes a strong tendon at the lower end of the fore-arm which is attached to the pisiform bone ; we find a very loose mucous bursa between
 
it and this bone.
 
 
 
It flexes the hand and inclines it toward the ulna.
 
 
 
V. FLEXOR DIGITORUM COMMUNIS SUBLIMIS.
 
 
 
§ 1153. The flexor digitorum communis sublimis muscle, Epilrochlophalanginien commun , Ch. (JM. flexor digitorum communis sublimis , s.
 
perforatus ), arises below the four preceding, by a much larger head,
 
from the lower part of the anterior face of the inner condyle of the
 
humerus, from the inner part of the capsular ligament of the elbow
 
joint, and from the inner face of the coronoid process of the ulna ; it
 
also arises by a small slip from the inner face of the radius at the lower
 
end of the supinator brevis muscle. Tong before this slip has joined
 
the upper head, it divides into three bellies, of which the internal and
 
posterior divide still lower into two others. Each of these bellies
 
becomes a tendon, which all pass under the special palmar ligament
 
of the carpus to arrive at the palm of the hand.
 
 
 
Nearly opposite the centre of the first phalanx each tendon divides
 
into two slips which unite farther on the second phalanx, so that their
 
inner fibres interlace and again separate below this point to attach
 
themselves behind the middle of the second phalanx to its radial and
 
ulnar edges.
 
 
 
These tendons are surrounded by a common sheath, near the lower
 
extremity of the fore-arm, which, when arrived at the carpus, divides
 
into several sacs, each of which goes with one of them to the base of
 
the first phalanx. This muscle flexes the second phalanx of the
 
fingers.
 
 
 
§ 1154. One of the tendons, particularly that of the little finger, is
 
sometimes deficient ; it is then replaced by one of the tendons of the
 
flexor profundus muscle ; sometimes a belly of this muscle, especially
 
that which belongs to the index finger, is entirely separated from the
 
others, and divided besides into two fleshy portions by a long central
 
tendon. As the anomaly is seen more commonly in the belly of the
 
indicator finger, it is worthy of remark, from its analogy with the outer
 
 
 
 
 
descriptive anatomy.
 
 
 
 
 
133
 
 
 
 
 
face of the fore-arm, since it represents the proper extensor of the index
 
finger, and more, as the latter is also digastric in some subjects.
 
 
 
 
 
VI. FLEXOR DIGITORUM PROFUNDUS.’
 
 
 
§ 1155. The flexor digitorum profundus muscle, Cubit n-phalangettien commun, Ch. (JVJ. flexor digitorum communis profundus, s. suadus
 
perforons), is stronger than the preceding, which covers it anteriorly, and
 
arises from the upper two-thirds of the inner and posterior faces of the
 
ulna, so as to envelop this bone almost entirely, and divides, but much
 
deeper than the flexor sublimis, into four bellies, which become as many
 
tendons. These tendons are retained together by numerous intermediate filaments and by folds of the mucous sheaths, and pass under
 
the palmar ligament of the carpus, with those of the preceding, and go
 
to the same fingers. In this place we see a fissure along the upper
 
and lower faces. They pass through the sheath of the flexor sublimis,
 
afterwards become broader and thinner, and are attached to the base
 
of the third phalanx.
 
 
 
This muscle flexes the third phalanx of the fingers.
 
 
 
§ 1156. Sometimes a muscle proceeds between the flexor sublimis
 
and the flexor profundus, and extends from the inner condyle of the
 
humerus to the latter ;(1) and again, a muscular fasciculus arises from
 
the flexor pollicis longus as high as the wrist, which is attached by a
 
tendinous expansion to that tendon of the flexor profundus which goes
 
to the index finger.(2)
 
 
 
 
 
VII. LIGAMENTS OF THE FLEXORS OF THE FINGERS.
 
 
 
§ 1157. The tendons of the flexor profundus and sublimis are surrounded in two places by fibrous ligaments and mucous sheaths. 1
 
 
 
§ 1158. The upper fibrous ligaments are the common palmar ligament and proper palmar ligament of the carpus.
 
 
 
Below them we find the upper mucous sheath, an elongated sac,
 
which surrounds all the tendons of the two flexors, commences about
 
an inch and a half above the radio-carpal articulation, and extends to
 
the centre of the carpus. Its outer layer is attached to the palmar
 
ligaments of the bones of the carpus, and to the interossei muscles.
 
Numerous folds arise from all the internal face of this outer layer which
 
go inward, surround the tendons of the two flexors, and unite them but
 
very loosely.
 
 
 
§ 1159. The second place, where the common flexors are surrounded
 
with similar ligaments, is that portion which corresponds to the lower
 
face of the fingers.
 
 
 
§ 1160. The lower fibrous ligaments are situated outwardly, and
 
form for the mucous sheath an envelop, which is divided on account
 
of the motion of the fingers,
 
 
 
(1) Gantzer, p. 13.
 
 
 
(2) Gantzer, ibid.
 
 
 
 
 
134
 
 
 
 
 
DBSCJIII’TIVE ANATOMY.
 
 
 
 
 
The strongest portion is termed the ligamentous sheaths ( Lig . vaginalia). These sheaths are formed almost entirely of transverse
 
fibres ; in part, however, especially on the surface, of oblique fibres
 
which cross the preceding. They are strongly extended, like a bridge,
 
from the radial to the ulnar edge of the first and second phalanges.
 
That of the indicator finger is much stronger than the others in every
 
respect.
 
 
 
The feeblest which stand more distinct, extend in the same manner
 
over the metacarpo-phalangoean and the second phalangoean articulations. Their size diminishes much from the first to the third articulation. They are called the ligamentous rings of the articulations
 
( annuli juncturarum ligament osi).
 
 
 
Analogous fasciculi are found between the preceding and the ligamentous sheaths ; these are the oblique or crucial rings of the first and
 
second •phalanges ( annuli obliqui , s. cruciati phalangis primes et
 
secundcE ).
 
 
 
§ 1161. The inner faces of these fibrous ligaments are covered with
 
elongated mucous sheaths, which begin some lines behind the metarcarpo-phalangœan articulation, are attached in this place to the flexor
 
sublimis and profundus of each finger, and extend to the centre of the
 
terminating phalanx. Their upper part is inserted in the upper part of
 
the palmar face of the phalanges. The tendons of the two flexors are
 
mostly loose in these mucous sheaths, of which each finger possesses
 
a separate one ; however, from the dorsal face of the sheaths, that which
 
covers the palmar face of the fingers, arise several broader and narrower
 
irregular folds, the largest of which contains more or less fat ; these
 
proceed from before backward, are very thin from one side to the other,
 
and are attached to the tendons of the flexor sublimis and profundus.
 
The upper are usually very thin and rounded, and are attached to the
 
radial slip of the flexor sublimis. They are generally deficient in one
 
or several fingers.
 
 
 
The succeeding which are larger are also more constant ; they
 
arise near the second phalangcean articulation, and are usually attached
 
to the tendon of the flexor sublimis, where its two slips unite. Usually
 
we find also within or on their sides other prolongations, which go to
 
the tendons of the flexor profundus.
 
 
 
A third prolongation generally arises from the base of the third phalanx which is attached directly to the two anterior slips of the flexor
 
sublimis, unites them, goes from this point to the anterior extremity of
 
the flexor profundus which covers the third articulation, and is there
 
attached in all its extent.
 
 
 
Other single or divided prolongations extend also in many parts
 
between the tendons of the two flexors in their course along the
 
fingers.
 
 
 
These are the short and long accessory or vascular ligaments of the
 
flexors (vincula tendinum sublimis el profundi accessoria , s. vasculosa
 
brevia et longa).
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
135
 
 
 
 
 
VIII. FLEXOB POLLICIS LONGUE.
 
 
 
§ 1162. Th e flexor proprius pollicis longus muscle, Radio-phalangettien du pouce , Ch., is much feebler and shorter than the preceding,
 
with the second belly of which its central part usually adheres more
 
or less intimately. It arises by a small distinct slip from the tubercle
 
of the ulna, but in most of its length it arises by fleshy fibres from the
 
lower two-thirds of the inner face, and the anterior edge of the radius.
 
The strong tendon which terminates it passes under the palmar ligament with those of the two preceding muscles, and goes between
 
the abductor and flexor pollicis brevis on the internal face of this finger,
 
and is attached not far from its inferior edge to the second phalanx.
 
This tendon is surrounded by a special mucous sheath from the lower
 
extremity of the fore-arm to the centre of the first phalanx.
 
 
 
It flexes the second phalanx of the thumb.
 
 
 
We sometimes find a second head which comes from the inner
 
condyle of the humerus, and which is only a greater development of its
 
upper slip.
 
 
 
IXL .PRONATOR Q.UADR ATUS.
 
 
 
§ 1163. The pronator quadratus muscle, Cubito-radial , Ch. (JV I. pronator quadratus, s. inferior), is an almost equilateral quadrilateral muscle, being rather more long than broad, which occupies the lowest part of
 
the inner face of the fore-arm, where it is covered by the tendons of all
 
the long muscles. Its fibres are oblique and extend from the posterior
 
edge and from the inner face of the ulna to the inner face and anterior
 
edge of the radius.
 
 
 
This muscle rotates the radius, and the hand with it, on its axis from
 
behind forward and from without inw T ard.
 
 
 
§ 1164. It is sometimes deficient, (1) as in several mammalia.
 
 
 
Again, it is sometimes divided into two bellies which are entirely
 
separated, the fibres of which proceed in opposite directions and cross. (2)
 
 
 
 
 
ARTICLE FIFTH.
 
 
 
MUSCLES OF THE HAND
 
 
 
§ 1 165. The musclesof the hand(3) arisefrom the tendonsof the flexor
 
profundus, from the carpus, and from the metacarpus, and are attached
 
to the metacarpal bones and also to the phalanges. They are principally designed to approximate and separate the fingers and serve less
 
 
 
(1) We know of one instance.
 
 
 
(2) We have once seen this.
 
 
 
(3) Albinus, leones musculorum inanus iv., ad ealeem hist, muscul., Leyden, 1734,
 
 
 
 
 
136
 
 
 
 
 
descriptive anatomy.
 
 
 
 
 
to flex them. Hence they are divided into abductors, adductors, and
 
flexors. The adductors and abductors which are attached to the two
 
external fingers, the thumb, and the little finger, fulfill only the one or
 
the other of these two functions, while those which move the other
 
three fingers are both adductors and abductors ; because, in approxiting a finger toward that on one side, they necessarily separate it
 
from that of the other side.
 
 
 
The abductor and adductor muscles of the fingers, except the thumb,
 
are] called the interossei muscles, from their situation ; the flexors of
 
the second and third and also one of the little finger are called the lumbricales , from their form.
 
 
 
 
 
I. LUMBRICALES.
 
 
 
§ 1166. The four lumbricales muscles, Palmi-phalangien, Ch., are
 
long, rounded muscles, which arise fleshy from the lower face and the
 
radial edge of the tendons of the flexor digitorum profundus toward
 
the upper end of the metacarpus. They proceed at the side above and
 
below these tendons and arrive at the fingers, where they become thin
 
tendons, which are reflected on the radial face of the first phalanx,
 
enlarge, and blend with the anterior edge of the tendon of the extensor
 
muscle.
 
 
 
They flex the first phalanx.
 
 
 
§ 1167. We often find one or more of these muscles more or less
 
completely double, and then the supernumerary head or the whole
 
muscle is inserted in the ulnar side of the adjacent finger.
 
 
 
II. INTEROSSEI.
 
 
 
§ 1168. The interossei muscles, Metacarpo-phalangiens latéraux
 
sus-pahnaire and the métacarpo-phalangiens Intermix, Ch., are situated
 
between the metacarpal bones. Their anterior tendons are attached
 
partly to the lateral faces of the posterior heads of the first phalanges,
 
partly also to the extensors of the fingers. They are divided into two
 
classes, the external (JVT. interossei externi , s. bicipites), and the internal
 
(M. interossei interni , s. simplices.)
 
 
 
I. INTEROSSEI EXTEBNI.
 
 
 
§ 1169. The common characters of the external interossei muscles are : 1st. They appear on the dorsal and palniar faces of the hand.
 
2d. They arise from the corresponding faces of two metacarpal
 
bones by two heads, which is inserted in a common tendon.
 
 
 
We number four, which are attached to the index, middle, and little
 
fingers.
 
 
 
The first, which is the strongest, is situated between the thumb and
 
the index finger. It differs from the others, not only in volume but
 
also in the complete separation of its two heads.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
137
 
 
 
 
 
The anterior and stronger head arises from the upper larger part of the
 
ulnar face of the metacarpal bone of the thumb. The posterior, which
 
is smaller, arises from almost all the radial face of the second metacarpal
 
bone. These two heads unite below in a common tendon, which is
 
attached partly to the radial face of the base of the first phalanx
 
of the index finger, and partly blends with the tendon sent by the
 
common extensor of the same finger.
 
 
 
The great distance between the two heads has led some anatomists
 
to consider them as two distinct muscles : they have termed the anterior head the adductor indicts and the posterior the first internal interosseous muscle.
 
 
 
It draws the second finger toward the thumb.
 
 
 
The other external interosseous muscles are much smaller ; their
 
heads unite much higher even in the centre of their course.
 
 
 
The second arises by a smaller anterior and deeper head from the
 
ulnar side of the second, and by a larger posterior looser head from the
 
radial side of the third metacarpal bone. It is also attached to the radial
 
side of the middle finger.
 
 
 
This muscle brings the middle finger toward the index finger.
 
 
 
The third, situated in the space between the third and fourth metacarpal bones, is inserted in the ulnar side of the middle finger.
 
 
 
It brings the middle finger toward the fourth.
 
 
 
The fourth is placed between the fourth and fifth metacarpal bones,
 
and is inserted in the ulnar side of the fourth finger.
 
 
 
It brings the ring finger to the fifth,
 
 
 
II. INTEBOSSEI INTERNS.
 
 
 
§ 1170. The interossei intemi muscles are three in number, when
 
we do not consider the posterior head of the first external interosseous
 
muscle as the first internal interosseous muscle. They are attached to
 
the second, fourth, and fifth fingers. They arise by a single head from
 
the lateral face of the metacarpal bone of the finger to which they are
 
attached, and are very distinct in the palm of the hand.
 
 
 
The first arises from the ulnar face of the second metacarpal bone,
 
is inserted in the ulnar side of the base of the first phalanx of the indicator finger, and blends in the same place with the tendon sent by the
 
common extensor to this finger. It separates the index finger from the
 
thumb and draws it toward the middle finger.
 
 
 
The second comes from the radial side of the fourth metacarpal bone.
 
 
 
The third arises from the radial side of the fifth metacarpal bone.
 
 
 
The second is attached to the first phalanx of the fourth finger, and
 
the third to the first phalanx of the fifth finger.
 
 
 
Both draw the fingers to which they are attached from the side of
 
the thumb or from the radial edge of the hand, and consequently inward.
 
 
 
VOL. II.
 
 
 
 
 
18
 
 
 
 
 
138
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
The index finger has then an external and an internal interosseous
 
muscle ; the middle finger has two external interosseous muscles ; the
 
fourth finger an external and an internal, and finally the fifth finger
 
an internal interosseous muscle.
 
 
 
§1171. The interosseous muscles rarely present anomalies. We
 
have however found the second external interosseous muscle attached
 
to the ulnar side of the index finger, and the first internal interosseous
 
muscle attached not to this finger but to the radial side of the third — a
 
variety the more interesting in the history of the inversion of the organs
 
because it presents an exact repetition of the normal formation of the
 
foot, and because the hand in which we found it presented also an adductor of the thumb, formed likewise in the same manner as that of the
 
great toe.
 
 
 
III. MUSCLES OF THE THUMB.
 
 
 
§ 1172. The metacarpal bone of the thumb is surrounded by a considerable muscular mass, called the ball of the thumb (thenar), formed
 
of four muscles, the abductor pollicis brevis, the opponens pollicis, the
 
flexor pollicis brevis, and the adductor pollicis.
 
 
 
I. ABDUCTOR POLLICIS BREVIS.
 
 
 
§ 1173. The abductor pollicis brevis muscle, Carpo-sus-phalangien
 
du pouce, Ch., the most superficial of the four muscles, arises from the
 
anterior part of the inner face of the ligament of the carpus and of the
 
os trapezium. It is generally blended by a short intermediate tendon
 
with the tendon of the abductor longus (§1139), and extending forward
 
along the radial edge of the metacarpal bone of the thumb, it is attached by a short tendon to the outer face of the posterior head of its
 
first phalanx. It also usually blends more anteriorly with the tendon
 
of the flexor pollicis brevis muscle.
 
 
 
It separates the thumb from the index finger and extends it a little.
 
 
 
II. OPPONENS POLLICIS.
 
 
 
§ 1174. The opponens pollicis muscle, Carpo-metacarpien du pouce,
 
Ch., is smaller than the preceding, which it partly covers, and its form
 
is rhomboidal. It arises below it by a broad edge and by very broad
 
tendinous fibres from the anterior part of the inner face of the palmar
 
ligament and from the os trapezium, then descends to the metacarpal
 
bone of the thumb, and is attached by a short tendon to all the anterior
 
part of its radial edge.
 
 
 
It draws the thumb inward and turns it on its axis ; so that it opposes its palmar face to that of the other fingers.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
139
 
 
 
 
 
III. FLEXOR POLLICIS BREVIS.
 
 
 
§ 1175. The flexor pollicis brevis muscle, Carpo-phalangien du pouce,
 
Ch. {J\l. flexor pollicis brevis , s. mesothenar , s. antithenar ), is stronger
 
than the two preceding. Its upper extremity, which is very much
 
divided, arises first below and inward from the palmar ligament and the
 
os trapezium, on the other side from the palmar face of the os trapezoides, from the os magnum, and the os pyramidale. It partly covers
 
the preceding and is attached to the outer sesamoid bone of the thumb.
 
 
 
It flexes the first phalanx of the thumb.
 
 
 
§ 1176. The largest head, which comes from the palmar ligament,
 
is sometimes entirely separated from the other, which is smaller and
 
situated lower ; so that this muscle is in fact double. On the other
 
hand, it often happens that the small head is entirely blended with the
 
adductor pollicis muscle.
 
 
 
IV. ADDUCTOR POLLICIS.
 
 
 
§ 1177. The adductor pollicis muscle, JVIetacarpo-phalangien du
 
pouce , Ch. (JVT. mesothenar , s. hypothenar ), is the strongest and the
 
deepest of the four muscles of this finger. Its form is triangular, the
 
base looking toward the ulnar edge and the summit toward the radial
 
edge. It arises by fleshy and tendinous fibres from the palmar face of
 
the os magnum, and in a greater or less extent from the palmar edge
 
of the third metacarpal bone, goes forward and outward, and is attached
 
by a short tendon to the inner sesamoid bone.
 
 
 
This muscle draws the thumb toward the index finger and slightly
 
rotates it on its axis, so that it turns its palmar face toward that of the
 
other fingers.
 
 
 
§ 1178. Sometimes it divides into a posterior and an anterior belly,
 
which are completely distinct, the posterior being the larger. In this
 
case the first arises only from the os magnum or at the same time from
 
this bone and a small upper portion of the third metacarpal bone : as
 
to the second, it comes from the lower part of the anterior head of the
 
third and fourth metacarpal bones ; sometimes also from the fifth as
 
well as from the capsular ligament of the first phalangean articulation,
 
and goes across or a little obliquely from before backward, to the first
 
phalanx of the thumb, where it unites with the posterior head.
 
 
 
This anomaly is worthy of remark, as it coincides perfectly with the
 
normal arrangement of the adductor of the large toe.
 
 
 
IV. MUSCLES OF THE LITTLE FINGER.
 
 
 
§ 1179. The little finger is moved by three muscles, an abductor, a
 
flexor, and an adductor.
 
 
 
 
 
140
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
J. ABDUCTOR MINIMI DIGITI.
 
 
 
§ 1180. The abductor minimi digiti muscle, Carpophalangien du
 
petit doigt , Ch., the shortest of these three muscles, extends along the
 
ulnar edge of the metacarpus. It arises by short tendinous fibres from
 
tire pisiform bone, and near the first phalanx of the finger becomes a
 
small flat tendon, which blends with the ulnar edge of the tendon of its
 
extensor.
 
 
 
It separates the little finger from the others.
 
 
 
II. FLEXOR MINIMI DIGITI.
 
 
 
§ 1181. The flexor minimi digiti muscle (JVF. flexor proprius digiti
 
quinii ) is covered by the preceding. It arises below and before it from
 
the pisiform bone and from the unciform process of the unciform bone :
 
it forms a short tendon forward, which is attached to the radial side of
 
the first phalanx of the little finger.
 
 
 
It flexes the little finger and separates it from the others.
 
 
 
It is often deficient and then the preceding is more developed.
 
 
 
III. ADDUCTOR MINIMI DIGITI QUINTI,
 
 
 
§ 1182. The adductor minimi digiti muscle, Curpo-metacarpien du
 
petit doigt , Ch. ( J\'L adductor digiti quinii) ) is thickest and shortest, and
 
arises from the lower anterior edge and the outer face of the unciform
 
process of the unciform bone, goes upward, and is attached to all the
 
ulnar face of the metacarpal bone of the fifth finger.
 
 
 
It carries the little finger forward and draws it toward the others,
 
causing it to rotate around its axis on the metacarpal bone. When it
 
acts in concert with the opponens pollicis muscle, which very much
 
resembles it, the cavity of the palm of the hand enlarges.
 
 
 
§ 1183. The proper muscles of the thumb and little finger are
 
only the lumbricales or interossei muscles largely developed and
 
divided into several fasciculi. We must consider the flexor pollicis
 
brevis muscle as the first lumbricalis. The abductor pollicis brevis
 
and the opponens pollicis correspond to an external ; the adductor represents an internal interosseous muscle.
 
 
 
The abductor and the flexor minimi digiti muscles form only one
 
muscle, which represents the last external interosseous muscle.
 
 
 
The adductor minimi digiti muscle is only an enlarged internal interosseous muscle.
 
 
 
 
 
MYOLOOT.
 
 
 
 
 
141
 
 
 
 
 
CHAPTER II.
 
 
 
MUSCLES OF THE LOWER EXTREMITIES.
 
 
 
§ 1184. The muscles which have with the upper section of the
 
abdominal members relations similar to those which exist between the
 
superficial muscles of the back and of the region of the shoulder, or the
 
broad muscles of the abdomen, have already been examined. We may
 
then pass immediately to those which go from the first section of the
 
bones of the lower extremities to the femur ; but we must here also
 
commence by describing the general aponeurotic envelop.
 
 
 
 
 
ARTICLE FIRST.
 
 
 
APONEUROTIC 8HEATH OF THE LOWER EXTREMITIES.
 
 
 
§ 1185. Most of the muscles of the lower extremities, especially
 
those of the thigh, leg, and sole of the foot, are enveloped by an aponeurotic expansion, which is not arranged every where in the same
 
manner.
 
 
 
This expansion is called on the thigh the fascia lata , on the leg the
 
crural aponeurosis, in the sole of the foot the plantar aponeurosis.
 
 
 
The first two form a whole more continuous with each other than
 
with the plantar aponeurosis, and are also still more similar in their
 
form, as they surround the thigh and the leg.
 
 
 
The fascia lata commences behind on the gluteæus maximus muscle,
 
where it is very thin, and gradually loses itself at its upper portion. It
 
arises forward from the iliac crest and from the Fallopian ligament. It
 
â– extends as far as the knee. It adheres very intimately by the upper
 
and external part of its anterior edge to the lower edge of the tendon of
 
the obliquus externus abdominis muscle, to which it is much more
 
loosely attached on its inner side.
 
 
 
It is thickest at the outer part and thinnest at the inner part of the
 
thigh. It is half a line thick in every part and above even a line in the
 
first region, while it hardly equals the twelfth of a line in the second.
 
In general it is evidently formed of two layers of fibres : the internal is
 
stronger and its fibres are longitudinal ; the external is weaker and its
 
fibres are oblique downward, inward, and backward, and are more insulated, and gradually approach each other from below upward.
 
 
 
From the inner face of this aponeurosis arise septa which extend
 
between most of the muscles of the thigh which they separate from
 
each other ; we readily distinguish in most of these septa transverse
 
and oblique fibres.
 
 
 
 
 
142
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
The fascia lata presents oblique fibres in every part In many
 
places, especially at the inner portion of its circumference, these fibres
 
are extended over a layer which is not evidently fibrous, especially
 
forward, but at the outer part this layer is manifestly formed of longitudinal fibres, and at the same time its inner face presents in different
 
parts more insulated oblique fibres, so that here the aponeurosis evidently consists of three layers.
 
 
 
The outer part of the crural aponeurosis is also much thicker, and
 
formed in this part of two layers ; the fibres of the internal are longitudinal, those of the external, which is weaker, are oblique.
 
 
 
At the upper part of the aponeurosis the direction of the oblique fibres
 
is inversely that of the oblique fibres of the fascia lata, that is, they proceed forward, downward, and inward.
 
 
 
At the lower part of the crural aponeurosis they have an opposite
 
direction, and at the same time other fibres are developed on the inner
 
side of the aponeurosis, which are oblique from behind forward
 
and from above downward.
 
 
 
These outer and inner fibres cross on the anterior face of the articulation of the foot, and as they increase in strength in this part they
 
there form the crucial ligament ( Lig . cruciaturn ), composed of two
 
fasciculi, which cross each other in the centre. One of these fasciculi
 
descends from the outer malleolus, goes downward and inward, and is
 
attached to the tibial side of the first metatarsal bone. The second
 
arises from the internal malleolus, and goes to the tuberosity of the
 
fifth metatarsal bone.
 
 
 
Below, they are both continuous with the thin aponeurosis of the
 
back of the foot, which covers the tendon of the extensor digitorum
 
longus and the belly of the extensor communis digitorum pedis, and
 
is lost near the anterior extremity of the metatarsus.
 
 
 
This aponeurosis at the back of the foot is often much stronger
 
toward the posterior end of the first metatarsal bone in this place,where it passes over the tendon of the extensor proprius pollicis pedis,,
 
than in the rest of its extent, and it is formed of very evident transverse
 
fibres, which are attached internally to the inner side of the metatarsus,
 
and outside to a special fasciculus of the extensor brevis digitorum
 
pedis. In this case, this portion of the aponeurosis of the foot is provided with a proper tensor muscle.
 
 
 
II. TENSOR VAGINÆ FEMORIS.
 
 
 
§ 1186 . The aponeurosis of the fascia lata, like most of the aponeurotic expansions which surround the muscles, has a proper muscle
 
called the tensor vaginic femoris muscle, llio-aponeurosi-f amoral , Ch.
 
(M. tensor fasciœ latœ).
 
 
 
This muscle is situated at the anterior edge of the upper part of the
 
lateral face of the thigh. It arises by a short but very strong tendon
 
from the outer face of the anterior and superior spine of the ilium.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
143
 
 
 
 
 
Thence it goes downward and outward, gradually enlarges, and is
 
continuous by very short tendinous fibres, towards the summit of the
 
middle third of the thigh, with the fascia lata, which is united with its
 
outer face more firmly than with any other muscle.
 
 
 
 
 
ARTICLE SECOND.
 
 
 
MUSCLES OF THE PELVIS.
 
 
 
§ 1187. The muscles of the pelvis arise partly from its outer face,
 
partly from its inner face, and partly from the lumbar portion of the
 
vertebral column ; they are attached to the upper part of the femur
 
which they extend, flex, and turn around its axis.
 
 
 
I. EXTENSORS OF THE THIGH.
 
 
 
§ 1188. The thigh is extended by three muscles called the glutœi,
 
situated over each other ; and they cover the outer face of the iliac
 
bones, and descend outward, downward, and forward toward the femur.
 
 
 
I. GLUT2EUS MAXIMUS.
 
 
 
§ 1189. The gluiœus maximus muscle, Sacro-femoral, Ch., is the
 
largest of all the muscles of the body, and is nearly a regular rhomboid.
 
It arises by its posterior and inner edge from the posterior part of the
 
outer lip of the crest of the ilium, from the lower part of the posterior
 
face of the sacrum, from the sacro-sciatic ligament, and from the sciatic
 
tuberosity. It arises by these différent points by short tendinous fibres,
 
goes from within outward and from above downward, forming a very
 
strong and thick muscle, composed of distinct and large fasciculi which
 
are loosely connected with each other. It is attached by a broad and
 
very strong tendon which is continuous below with the lateral part of
 
the fascia lata to the lower part of the large trochanter, and to the linea
 
aspera which descend from this tubercle.
 
 
 
Several mucous bursae are found on the inner face of the lower tendon
 
of this muscle. The largest and at the same time the uppermost is
 
situated between it and the outer face of the large trochanter. Farther
 
backward and downward we find another which is also large but a
 
little smaller, between it the upper extremity of the vastus externus
 
muscle and the lower end of the tensor vaginae femoris muscle. Finally, between this muscle and the femur, farther backward and downward, are two which are smaller.
 
 
 
The glutæus maximus extends the thigh, brings it toward the vertebral column, rotates it a little outward, and approximates it to that of
 
the side opposite. When it acts from below upward it draws the iliac
 
bones downward, inward, and forward.
 
 
 
 
 
144
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
II. GLUTÆUS MEDIUS.
 
 
 
§ 1190. The glutœus médius muscle, Grand ilio-trochanierien, Ch.,
 
is a large muscle, but smaller and closer than the preceding, and has
 
a triangular form. It is covered at its posterior and lower part by the
 
glutæus maximus, and forward by the fascia lata only, with which it
 
is intimately connected. It arises from the outer lip of the crest of the
 
ilium, and from the upper and anterior part of the outer face of the
 
iliac bones which is situated between the iliac crest and the curved
 
line. Its posterior fibres are oblique from behind forward and from
 
without inward ; the anterior go from above downward. It proceeds
 
towards the large trochanter, and is attached to its outer face by a
 
broad, short, and very strong tendon, which blends with that of the
 
glutæus maximus muscle.
 
 
 
A small mucous bursa exists between the upper face of this muscle,
 
the pyrifarmis, the gemellus superior, and the inner face of the large
 
trochanter.
 
 
 
The glutæus médius muscle raises the femur, separates it from that
 
of the opposite side, and inclines the pelvis as much as possible towards
 
its side.
 
 
 
Its posterior part turns the thigh outward, and its anterior turns it
 
inward.
 
 
 
 
 
III. GLUTÆUS MINIMUS.
 
 
 
§ 1191. The glutœus miniums muscle, Petit ilio-trochanterien, Ch.,
 
has the same form as the preceding, while it is much smaller and is
 
entirely covered by it. It arises directly below it by its upper face and
 
anterior edge from the curved line, and from the anterior and lower
 
part of the outer face of the iliac bones. It is attached by a short and
 
strong tendon to the upper edge of the upper part of the inner face of
 
the large trochanter.
 
 
 
A small synovial capsule exists forward between it and the large
 
trochanter.
 
 
 
Its action is the same as that of the preceding.
 
 
 
II. MUSCLES WHICH ROTATE THE THIGH OUTWARDLY.
 
 
 
§ 1192. The thigh is turned outward by six muscles, the pyriformis,
 
the obturator internus, the obturator externus, the two gemelli, and
 
the quadrat us femoris.
 
 
 
I. PYRIFORMIS.
 
 
 
§ 1193. The pyriformis muscle, Sucro-lrochanterien , Ch. (JVT. pyriformis, pyrimidalis, iliacus externus), is a small muscle of an oblong
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
145
 
 
 
 
 
triangular form coming from the cavity of the abdomen, where it arises
 
by three or four digitations from the sacrum. It arises from the anterior
 
face of this bone, between the third and fourth, the second and third,
 
and the first and second pairs of the anterior foramina of the sacrum, ,
 
and from the inner face of the posterior and lower spine of the ilium,
 
and from the upper part of the posterior edge of the iliac fossa. It
 
descends through this last behind the upper part of the descending
 
branch of the ischium, goes outward and forward, and is attached by
 
a rounded, strong, and proportionally broad tendon to the summit and
 
upper part of the inner face of the large trochanter.
 
 
 
There is a small mucous bursa between its tendon and the gemellus
 
superior muscle.
 
 
 
It rotates the thigh outward, separates it from that of the side opposite,
 
and raises it a little.
 
 
 
§ 1194. It sometimes divides into an upper and a lower portion,
 
between which the glutæal nerve passes. (1)
 
 
 
II. OBTURATOR INTERNUS.
 
 
 
§ 1195. The obturator internus muscle, Sous-pubio-trochanterien
 
interne , Ch. (AT. obturator internus , s. marsupialis, marsupialis internus ), arises from the inner face of the obturator foramen by radiating
 
fibres, which suddenly change their direction on leaving the pelvis and
 
turn at a right angle on the posterior face of the descending branch of
 
the ischium, covered before by this part of the bone, and behind by the
 
sacro-sciatic ligament. It then proceeds outward and forward, and is
 
attached by a strong tendon to the central part of the inner face of the
 
great trochanter, far below the tendon of the pyriformis muscle.
 
 
 
The arrangement of this tendon is then very peculiar. It begins
 
within the pelvis, a short distance from the descending branch .of the
 
ischium, but extends to about the centre of the space between the
 
ischium and the trochanter. It does not appear except on the anterior
 
and inner face of the muscle, where it consists of five very regular and
 
very distinct fasciculi, two of which form the upper and lower edge of
 
the muscle. The outer extremity of the middle belly extends between
 
them by four triangular fasciculi, and then immediately unite in a
 
strong tendon near the centre of the space between the ischium and
 
the great trochanter.
 
 
 
We find an oblong synovial capsule backward and outward between
 
the tendon of this muscle, the gemelli, and the great trochanter. A
 
second, external and rounded, situated between the ischiatic spine and
 
the great trochanter, surrounds the inner part of the tendon.
 
 
 
The obturator internus muscle turns the thigh directly outward and
 
draws it from that of the opposite side.
 
 
 
(1) Winslow, Expos, anat., vol. ii. p. 125.
 
 
 
 
 
VOL. II.
 
 
 
 
 
19
 
 
 
 
 
146
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
III. GEMELLI.
 
 
 
§ 1196. The gemelli muscles, Ischio-lrochanterien , Ch. {M. gemini
 
femoris, marsupiales extend , marsupium ), are two small oblong muscles, which are very similar and placed one over the other : they are
 
separated backward and outward by the tendon of the obturator internus muscle, also by that portion of this muscle which is situated out
 
of the pelvis. Their thin edges touch forward.
 
 
 
The upper arises by a pointed extremity from the lower part of the
 
posterior face of the ischiatic spine.
 
 
 
The lower arises by a broad and semilunar edge from the upper face
 
of the sciatic tuberosity and from the outer face of the descending
 
branch of the ischium. It gradually becomes thicker from within outward.
 
 
 
These two muscles are intimately connected with the obturator
 
internus, especially in their outer portions, entirely cover it, and are
 
attached with it to the inner face of the great trochanter.
 
 
 
They act in the same manner as the preceding.
 
 
 
§ 1197. The upper gemellus is frequently deficient(l) — a remarkable analogy with what is seen in the ape. (2)
 
 
 
We know of one case where both these muscles were deficient, as
 
in bats.
 
 
 
IV. QUADUATUS FEMORIS.
 
 
 
§ 1198. The qnadratus femoris muscle, Jschio-sous- trochanterien, Ch.,
 
is oblong and composed of transverse fibres. It is broader from without inward than in any other direction, and its height much exceeds
 
its thickness. It arises from the anterior edge of the sciatic tuberosity
 
and from a small part of the ascending branch of the ischium, passes
 
directly below the gemellus inferior to the posterior face of the femur,
 
where it is attached to a square impression situated between the roots
 
of the large and small trochanters above the posterior intertrochanterian
 
line.
 
 
 
We find a synovial capsule between it and the small trochanter.
 
 
 
It acts like the preceding.
 
 
 
§1199. Sometimes it does not exist. (3) More rarely it is divided
 
into several fasciculi, three of which have been known to exist. (4)
 
 
 
V. OBTURATOR EXTERNUS.
 
 
 
§ 1200. The obturator externus muscle, Sous-pubio-trochantericn
 
externe, Ch., is a rounded and triangular muscle, at first thin, but aftcr
 
(1) trantzor, p. 4.
 
 
 
(2) Vicq. d’Azyr, Knc. méth.syst. anat. des quadrup., p. 29.
 
 
 
(3) Albinus, loc. c it., p. 530. — We know of one case where the gemelli were very
 
large.
 
 
 
(4) Jancke, De caps. tend, arlicul., Leipsic, 1753.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
147
 
 
 
 
 
wards it becomes thicker and again grows thinner. It arises by a
 
rounded edge from the outer face of the ascending branch of the ischium
 
and by short tendinous fibres from the two branches of the pubis and
 
from the anterior face of the obturator membrane.
 
 
 
After contracting considerably in its outer portion and being covered
 
by a broad tendon on its anterior and posterior faces, it is reflected from
 
the anterior to the posterior face of the body, goes obliquely upward
 
and outward directly behind the neck of the femur, and is attached by
 
a short but very strong tendon to the fossa and to the inner face of the
 
great trochanter, a little distance below the tendons of the obturator
 
internus and the gemelli muscles.
 
 
 
It turns the thigh outward, draws it backward toward that of
 
the opposite side, and brings the anterior face of the pelvis to its
 
side.
 
 
 
III. FLEXORS OF THE THIGH.
 
 
 
§ 1201. There are two flexors of the thigh, the psoas magnus and
 
the iliacus internus muscles : to these a third is usually attached, the
 
psoas parvus muscle ; but this does not always descend to the thigh.
 
 
 
I. PSOAS MAGNUS.
 
 
 
§ 1202. The psoas magnus muscle, Prelombo-trochanterien , Ch. (J\I.
 
psoas magnus, s. lumbaris, s. lumbaris internus ), is a considerable elongated and rounded muscle, occupying the inner and anterior part of
 
the lumbar region directly on the side of the bodies of the lumbar vertebra. It extends from the upper extremity of this region downward
 
and outward to the inner face of the femur.
 
 
 
It arises by an external and posterior and an internal and anterior
 
range of short, flat, and triangular slips from the five lumbar vertebra
 
and the last dorsal.
 
 
 
The anterior slips come from the lateral faces of the short ligaments
 
and the intervertebral ligaments ; the posterior arise from the lower and
 
anterior parts of the transverse processes of the lumbar vertebra.
 
 
 
The belly of this muscle descends outward, covers the inner part of
 
the iliacus internus, becomes rounded as it descends, and forms before
 
the sacro-iliac articulation, rather outward than inward, a strong tendon
 
which emerges from the abdomen below the crural arch behind the
 
femoral vessels, and is attached to the anterior face of the small trochanter.
 
 
 
The psoas magnus muscle bends the thigh and turns it a little
 
inward, bends the trunk and turns it a little toward its side.
 
 
 
§ 1203. Between this muscle and the iliacus internus we sometimes
 
find another smaller, which arises from one or more transverse processes of the upper lumbar vertebra, proceeds on the outside of the
 
psoas magnus muscle, and is attached to the small trochanter and
 
 
 
 
 
148
 
 
 
 
 
descriptive anatomy.
 
 
 
 
 
sometimes to the tendon of the last. The crural nerve usually passes
 
between it and the psoas magnus muscle.(l) This anomaly reminds
 
us of the multiplication of the psoas magnus muscle in several apes. (2)
 
 
 
This and not the next muscle, as some anatomists assert, is the
 
muscle which sometimes exists abnormally.(3)
 
 
 
II. PSOAS PARVUS.
 
 
 
§ 1204. The psoas parvus muscle, Prelombo-pubien, Ch., has an
 
oblong square form, and arises from the lateral face of the first lumbar
 
vertebra, and from the intervertebral ligament between it and the last
 
dorsal vertebra, and sometimes from the twelfth dorsal vertebra. It
 
arises generally by one but sometimes by two slips, which come either
 
from the two vertebrae or only from the first lumbar.
 
 
 
Tt soon after becomes a flat and very long tendon, situated on the
 
outside of the psoas magnus muscle, crosses it to go inward, and is
 
attached in that part where the body of the pubis and ilium unite.
 
 
 
Below, the tendon becomes an aponeurosis, which covers the lower
 
part of the psoas magnus and of the iliacus, is attached to the crural
 
arch, and blends with the fascia lata.
 
 
 
This muscle bends the vertebral column forward and increases the
 
force of the two muscles situated above it, furnishing them with a point
 
of support.
 
 
 
§ 1205. It is sometimes deficient, but this is rare.
 
 
 
III. ILIACUS INTERNUS.
 
 
 
§ 1206. The iliacus internus muscle, Iliaco-troehanterien, Ch. (JVF.
 
iliacus, s. iliacus internus ), is a broad and considerable muscle, which
 
fills all the upper part of the inner face of the iliac bones, whence it
 
descends to the inner part of the thigh. It arises by a semicircular and
 
convex edge and by short tendinous fibres from the inner lip of the iliac
 
bone, and also by fleshy fibres from the inner face of this bone to near
 
the anterior and inferior iliac spine, goes inward and forward, becomes
 
in its course considerably narrower and thicker, and is attached a little
 
above the crural arch to the outside of the tendon of the psoas magnus
 
muscle, by which it is fixed to the anterior face of the small trochanter.
 
 
 
We find a considerable mucous bursa between the common tendon
 
of the psoas magnus and the iliacus internus muscle and the capsular
 
ligament of the coxo-femoral articulation. There is another, which is
 
smaller, between it and the small trochanter.
 
 
 
This muscle bends the thigh and carries it inward. It draws the
 
pelvis and with it the trunk downward and forward.
 
 
 
(1) We have seen it several times. — Albinus, p. 315.
 
 
 
(2) Valentine, Amph. zoot., p. 151.
 
 
 
(3) Kelch, Bcytrœge zur path, anat., p. 22.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
149
 
 
 
 
 
ARTICLE THIRD.
 
 
 
MUSCLES OF THE THIGH.
 
 
 
§ 1207. Among the muscles which form the mass of the thigh some
 
serve to move it and others act on the leg. Not only the first but also
 
some of the second arise from the bones of the pelvis.
 
 
 
The muscles of the first class are the adductors of the thigh ; those
 
of the second are the adductors, the flexors, and the extensors of the leg.
 
 
 
I. ADDUCTORS OF THE THIGH.
 
 
 
§ 1208. The two lower limbs are drawn toward each other by the
 
adductors ( adductor es ), which form almost all the internal and posterior
 
part of the muscular mass of the thigh. Three of these muscles in
 
particular have been termed the adductors. They have been considered
 
as forming only a single muscle, called the triceps muscle (JVf. femoris
 
triceps ), but wrongly, as they are not united by a common tendon.
 
The fourth has been described as a separate muscle, called the pectinœus , although it might be considered as a fourth head of the common
 
adductor, as well as the other three.
 
 
 
I, PECTINÆUS.
 
 
 
§ 1209. The pectinozus muscle, Sous-pubio-femoral, Ch. ( JW.pecti nœus, s. pectinalis), a flat, long, quadrangular muscle, arises by its upper
 
thin and horizontal edge from the crest of the horizontal branch of the
 
pubis, on which its upper and anterior face passes. It goes from above
 
downward, from within outward, and is attached by a perpendicular
 
edge to the upper end of the inner lip of the rough line of the femur.
 
 
 
We find a small synovial capsule below the small trochanter, betwmen
 
this muscle and the femur.
 
 
 
It draws the thigh toward that of the opposite side, raises it and carries it forward, turns it a little inward, and slightly inclines the pelvis
 
outward and downward.
 
 
 
§ 1210. We sometimes find a second pectinæus, which is smaller,
 
which blends below with the tendon of the other, and is attached above
 
to the inner part of the upper edge of the obturator foramen.(l)
 
 
 
§ 1211. The three adductors, properly so called, are distinguished
 
into the long, the short, and the great adductor.
 
 
 
II. ADDUCTOR LONGUS.
 
 
 
§ 1212. The adductor longus muscle, Pubio-femoral , Ch. (M. adductor femoris longus , caput primum tricipitis ), has the form of an ob
 
(1) Winslow, Expos, anat., vol. i. p. 117.
 
 
 
 
 
150
 
 
 
 
 
DESCRITTIVB ANATOMY.
 
 
 
 
 
long triangle. It is the second of the three adductors in size and the
 
longest of all. It arises by a short, narrow, but very strong tendon
 
from the inner part of the anterior face of the horizontal branch of the
 
pubis, from the spine of the pubis, and from the anterior part of the
 
symphysis pubis. Thence it goes outward and downward, in a direction more oblique than the preceding, becomes broader and at the same
 
time thinner, and is attached by a tendinous and interrupted edge to
 
the third quarter of the posterior lip of the rough line of the femur. Its
 
lower end usually unites to the vastus internus muscle.
 
 
 
Its action is nearly the same as that of the pectinæus.
 
 
 
§ 1213. It is sometimes divided into two. And again, it descends
 
much lower, by a thin tendon united to that of the adductor magnus :
 
so too in some mammalia and in birds the pectinæus or the other portions of the adductor muscle descend very low.
 
 
 
III. ADDUCTOR BREVIS.
 
 
 
§ 1214. The adductor brevis muscle, Sous-pubio-fcmoral, Ch., (JW.
 
adductor femoris brevis, s. adductor secundus, s. caput alterum tricipitis),
 
is rather a broad triangular muscle. It arises at the side of the tendon
 
of the gracilis muscle, but much higher and more externally than it,
 
and is closely united with its upper extremity. Its upper end, situated
 
directly below the adductor longus and formed of very short tendinous
 
fibres, arises from the inner part of the outer face of the horizontal branch
 
of the pubis. It is much broader and much shorter than the preceding,
 
goes less obliquely outward than it, and is attached to the posterior
 
face of the small trochanter and also to the upper third of the inner lip
 
of the rough line of the femur, by several strong tendinous slips, which
 
succeed each other from above downward.
 
 
 
At its lower extremity it is connected more or less intimately with
 
the pectinæus and the adductor magnus muscles.
 
 
 
It acts like the preceding.
 
 
 
§ 1215. It is often partially or wholly divided into two slips, which
 
forms a remarkable analogy between man and the ape.
 
 
 
IV. ADDUCTOR MAGNUS.
 
 
 
§ 1216. The adductor magnus muscle, Ischio-femoral , Ch. (M.
 
adductor femoris magnus, s. caput tricipitis tertium), is the largest of
 
the three proper adductor muscles ; it also has a triangular form, the
 
base of which rests in the thigh, and the apex looks toward the pelvis.
 
It arises from the anterior face of the descending branch of the pubis,
 
and is intimately connected in this part with the outer face of the lower
 
part of the tendon of the gracilis muscle. It arises also from the
 
ascending branch of the ischium and from the lower edge of the sciatic
 
tuberosity.
 
 
 
Its upper and anterior fasciculi go directly downward and outward.
 
The posterior and inferior on the contrary, which are attached to the
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
151
 
 
 
 
 
sciatic tuberosity, go from below upward, around and behind the latter,
 
so that the muscle seems at its upper part to have been twisted on
 
itself, and is much thicker there than in the rest of its coarse.
 
 
 
Before the extremity of the portion inserted in the sciatic tuberosity,
 
the upper edge, which is loose and fissured in a semilunar form, goes
 
toward the femur, where it is attached to the posterior lip of the linea
 
aspera, behind the pectinæus and the other two adductors, always
 
descending deeper than they. The lower tendon is very strong, particularly at its lower part, and extends to the posterior face of the inner
 
condyle of the femur.
 
 
 
About the latter fourth of the thigh this tendon is perforated by the
 
superficial vessels of the leg, which pass from its anterior to its posterior
 
face. It unites below to the vastus internus muscle.
 
 
 
T his muscle draws the thigh inward, carries it forward, turns its
 
anterior face a little outward, flexes the pelvis forward, and directs its
 
anterior face to the side.
 
 
 
§ 1217. We sometimes find it divided into two portions, as in apes.
 
 
 
II. MUSCLES OF THE THIGH WHICH MOVE THE LEG.
 
 
 
§ 1218. The muscles situated on the thigh forming its mass, and
 
which move the leg, are distinguished into adductors, extensors, and
 
flexors.
 
 
 
I. ADDUCTORS OF THE LEG.
 
 
 
§ 1219. Those nearest the surface are the adductors, of these there
 
are two, the sartorius and the gracilis.
 
 
 
A. SARTORIUS.
 
 
 
§ 1220. The sartorius muscle, Uio-pretibial, Cli., the longest of all
 
the muscles of the body, is very thin, and has an elongated square
 
form. The short tendon by which it arises descends lower on its external than on its internal edge. It is inserted directly at the side of
 
the tensor vaginæ femoris muscle, more inward and forward, on the
 
anterior and upper spine of the iliac bone. Thence it passes onward
 
and inward, above the lower part of the adductor iongus and adductor
 
magnus muscles. In this manner it attains the anterior face of the
 
thigh, where its lower portion goes to the inner face of the same part.
 
Thence it proceeds directly forward and at the side of the gracilis, and
 
soon becomes rounder and narrower, and forms a short rounded
 
tendon which, passing behind and below the inner condyle of the
 
femur, comes to the inner face of the leg. In this place it rests directly
 
on the upper part of the inner face of the tibia, it becomes broader, and
 
is at .'ached by its anterior edge to the inner face of this bone, near its
 
sp ! ' -, and is contiguous below with the aponeurotic expansion of the
 
leg.
 
 
 
 
 
152
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
This muscle flexes the knee, and when this articulation is bent it
 
turns the tibia inward, so that the end of the foot approaches the other.
 
When it acts in an opposite direction it draws the haunch a little forward and turns it inward.
 
 
 
§ 1221. We have met with one subject in which the sartorius
 
muscle did not exist.
 
 
 
Sometimes, on the contrary, there are two which may happen in
 
several different ways.(l) The normal muscle usually appears
 
curved inward, and the additional muscle terminates sooner below,
 
where it is attached either to the tendon of the first or to the femur.
 
 
 
Sometimes the fibres of the sartorius muscle are interrupted by a
 
considerable intermediate tendon which is firmly united to the fascia
 
lata. (2)
 
 
 
B. GRACILIS.
 
 
 
§ 1222. The gracilis muscle, Sous-pubio-pretibial , Ch. (JM. gracilis,
 
s. rectus internus), is a thin muscle of an oblong triangular form which
 
arises by abroad base which forms its upper edge, from the anterior face
 
of the lower portion of the descending branch of the pubis, and from
 
the upper part of the ascending branch of the ischium. Thence one
 
of its edges turns forward and the other backward, one of its faces outward and the other inward ; it goes to the inside of the thigh, and
 
above its latter sixth, becomes a thin and rounded tendon, which proceeds directly behind the lower part and the tendon of the sartorius,
 
and turns with it on the inner condyle of the femur. • It is at first
 
covered by it, and is then situated below it, and blended with it in its
 
anterior and inferior part, and is finally inserted a little lower down, in
 
the upper part of the inner face of the tibia.
 
 
 
It bends the knee, turns the leg inward, and draws the anterior face
 
of the iliac bones from the side to which it is attached.
 
 
 
II. EXTENSORS OF THE LEG.
 
 
 
§ 1223. The leg has four extensors which may very properly be
 
considered as one muscle with four heads, since they are attached to
 
a common tendon. They are situated directly below the fascia lata
 
aponeurosis on the anterior face, and on the sides of the thigh, and
 
form most of its muscular mass. A considerable mucous bursa exists
 
between them and the aponeurosis of the thigh. They are termed
 
the rectus femoris, the vastus internus, the vastus externus, and the
 
cruræus muscles.
 
 
 
A. RECHTS FEMORIS.
 
 
 
§ 1224. The rectus femoris muscle, Jlio-rotulien, Ch. {M. rectus
 
femoris, s. extensor cruris médius superficialis), is a strong elongated
 
 
 
(1) Huber, Act. n. c., vol. x. p. 114.— Rosenmüller, loc. cit., p. 7.— Gantzer, p. 14. '
 
 
 
(1) Kelch, loc. cit., p. 42, p. xxxv.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
153
 
 
 
 
 
pointed muscle situated on the anterior face of the thigh, directly under
 
the fascia lata aponeurosis in most of its length, except its upper part,
 
where it is covered by the sartorius muscle.
 
 
 
It arises by two points from the iliac bone by a very strong but short
 
tendon. In fact, this tendon is divided above into two heads, an upper
 
and a lower or external tendon.
 
 
 
The upper head, which goes directly downward, comes from the
 
anterior and inferior spine of the ilium. The lower, which is curved in
 
a semicircle, arises from the upper part of the edge of the cotyloid
 
cavity. These two heads soon unite to give rise to the upper common
 
tendon. This tendon soon disappears on the posterior part of the
 
muscle, but becomes much broader on the anterior, and descends to its
 
centre, gradually becoming thinner.
 
 
 
The central fleshy portion is composed of an outer and an inner
 
layer of fibres, which unite at an acute angle on the median line, so
 
that the arrangement of these fleshy fasciculi resembles in some measure a roof.
 
 
 
The fibres are much longer, and ascend much straighter the nearer
 
they are to its lower extremity. They are attached on both sides to
 
a prolongation of the upper tendon, the direction of which is from
 
before backward, which descends into the substance of the muscle from
 
its anterior face, and gradually diminishes from above downward. It
 
however continues perceptible to near the lower end of the fleshy
 
belly, that is, much lower than the broad and anterior part of the upper
 
tendon descends on its outer face. It is nowhere connected with the
 
posterior and inferior tendon.
 
 
 
The lower tendon is much longer but is weaker than the upper. It
 
ascends on the posterior face of the muscle, much higher than the upper,
 
descends on the anterior, so that the fleshy belly is situated for several
 
inches before and behind between two tendinous expansions. It
 
begins to be visible forward only towards the lower third of the thigh,
 
and is seen first on the two sides of the fleshy belly, which gradually
 
contracts. It is entirely loose after quitting the last fifth of the thigh.
 
When approaching the patella below, it becomes broader, and is
 
attached to the upper edge of this bone, and is intimately united with
 
the tendons of the other extensors.
 
 
 
This muscle extends the leg when the thigh is fixed, and the thigh
 
when the leg is fixed ; in the latter case it also bends the pelvis a little
 
and turns its anterior face obliquely to the opposite side.
 
 
 
B. VASTUS EXTERNUS.
 
 
 
§ 1225. The vastus externus muscle, ( JVL . extensor cruris vastus, s.
 
externus), ( 1) the largest of all the extensors of the leg, although much
 
shorter than the preceding, forms almost solely the muscular mass on
 
the outside of the thigh ; at the same time it extends very much
 
 
 
 
 
(1) This and the next two muscles are termed the Trifemoro-rotulien by Chaussier.
 
 
 
Vol. II. 20
 
 
 
 
 
154
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
backward and forward. It is considerably thick, but it is broader from
 
before backward than from within outward.
 
 
 
It arises by a slightly concave edge which inclines from before backward, from within outward, and from above downward, from the lower
 
part of the anterior and outer face of the great trochanter. The
 
upper half of its posterior edge, situated along the rough line of the
 
the femur, comes from the inner face of the outer wall of the fascia lata
 
aponeurosis. From all these points it gradually descends forward,
 
becomes narrower, and is finally attached, by an inferior tendon, to the
 
upper and outer edge of the patella. The inner part of this tendon is
 
covered some distance above its insertion by the tendon of the rectus
 
femoris muscle, to which it is even slightly united, although it is easily
 
separated from it as far as where it is inserted in the patella.
 
 
 
The muscular fasciculi go directly downward. The upper tendon
 
extends below the centre of the muscle on its outer face, and the lower
 
only to the centre of its inner face.
 
 
 
The vastus externus muscle extends the knee,- and most generally
 
raises the leg at the same time, and turns it a little outward.
 
 
 
C. VASTUS INTERNUS.
 
 
 
§ 1226. The vaslus interims muscle (JVf. extensor cruris , s. vastus
 
interims ) is a little shorter and much weaker than the preceding, with
 
which it is blended outwardly in a small portion of its upper extremity.
 
It arises by its upper edge, which descends obliquely inward, from the
 
anterior intertrochanterian line ; by a small part of its lower edge, from
 
a part of the anterior face of the femur situated below this fine ; and
 
by the upper part of its posterior edge, from the upper part of the anterior lip of the linea aspera. Its lower tendon is attached to the inner
 
part of the upper edge, and to the inner edge of the patella. The inner
 
part of this tendon is covered below by that of the vastus externus
 
which passes obliquely over it, and is attached to the patella before
 
it ; it adheres to this tendon, but is easily separated from it.
 
 
 
The upper tendon of this muscle descends over almost the whole of
 
the inner and loose face on the posterior half of the muscle, while the
 
lower disappears already below the centre of its outer face, principally
 
at its upper part.
 
 
 
This muscle extends the leg and turns it a little inward.
 
 
 
D. CRURÆUS.
 
 
 
§ 1227. The crurczus muscle, (JVT. cruralis, s. crurœvs , s. femorceus)
 
the shortest of the four extensors of the leg, is also nearly as strong as
 
the preceding. It arises by its posterior and inner face, directly below
 
this last, from the larger part of the anterior and the outer face of the
 
femur, excepting a small portion above, and from its lower third. The
 
posterior edge comes from the outer lip of the linea aspera. This
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
155
 
 
 
 
 
muscle covers also most of the anterior and outer faces of the femur.
 
It is attached by its lower tendon behind the vastus internus and the
 
vastus externus to the upper edge of the patella, and usually also at
 
its lower and outer part, by short fibres, to the synovial capsule, and
 
to the outer edge of the patella.
 
 
 
This lower and outer part is generally separated from the others,
 
particularly from their tendon.
 
 
 
The upper edge of this muscle is attached to the bones without any
 
appearance of a tendon. The lower tendon, the loose portion of which
 
is longer than that of the two preceding, begins on the contrary from
 
the middle of the anterior and loose face.
 
 
 
The cruræus muscle is mostly covered above by the vastus externus
 
and the vastus internus ; it is entirely covered below by the rectus
 
muscle, excepting however its outer and lower lateral face, where it is
 
concealed by the vastus internus muscle. Its lower part also is intimately connected with the two vasti, especially the externus.
 
 
 
A capsular ligament exists between its tendon, that of the vastus
 
externus, the capsular ligament and the patella ; this frequently opens
 
into the femoro-tibial articulation.
 
 
 
It extends the knee.
 
 
 
§ 1228. The common tendon of these four muscles, after enveloping the patella, goes to attach itself to the tuberosities of the tibia,
 
where we find a considerable synovial capsule between it and the bone.
 
 
 
E. 6UBCRÃœEALIS.
 
 
 
§ 1229. The subcruralis muscle is a small triangular muscle, which
 
always exists and is entirely covered by the lower part of the preceding. It arises from the lower fourth of the anterior face of the femur,
 
and is attached to the upper part of the anterior wall of the synovial
 
capsule of the knee. It draws this capsule in the motion of extending
 
the leg, and also prevents it from being injured.
 
 
 
III. FLEXORS OF THE LEG.
 
 
 
§ 1230. The flexors of the leg are situated on the posterior face of
 
the thigh. We number three, two internal and an external ; but the
 
latter arises by two heads. All arise at the side of each other from
 
the sciatic tuberosity, and are attached posteriorly to the bones of the
 
leg. They consequently bend the knee or draw the posterior faces of
 
the thigh and of the leg towards each other. They also extend the
 
coxo-femoral articulation when the leg is extended.
 
 
 
I. INTERNAL FLEXORS.
 
 
 
§ 1231. The two inner or tibial flexors arise from the sciatic tuberosity and are inserted in the upper end of the tibia. They are called
 
the semimembranosus and the seimtendinosus.
 
 
 
 
 
156
 
 
 
 
 
DESCHirTIVE ANATOMY.
 
 
 
 
 
’ A. SEMITENDINOSUS.
 
 
 
§ 1232. The semitendinosus muscle, Ischio-pretibial, Ch. (JVf. semitendinosus , s. seminervosus ), is an elongated muscle broader and thicker
 
above than below, partially covering the following, because it is extended more below it and nearer the surface. It arises from the inner
 
part of the posterior face of the sciatic tuberosity by a tendon which is
 
very distinct outwardly, while its summit adheres very intimately to
 
the inner edge of that of the long head of the biceps femoris muscle.
 
This muscle is the most internal of the three flexors, and goes directly
 
downward. Its lower tendon commences on its inner edge, a little below the centre of the fleshy belly ; from about the last fourth of the
 
thigh it forms a very strong rounded cord, which passes behind the
 
inner condyle of the femur to arrive at the tibia, and is attached, after
 
enlarging and becoming thinner, to the inner face, directly below the
 
gracilis muscle. It blends with the lower edge of the tendon of this
 
latter muscle, and generally divides below into an upper and a lower
 
slip.
 
 
 
We find a mucous bursa directly near its insertion, between its upper
 
tendon and that of the semimembranosus and the long head of
 
the biceps. There is also another, and sometimes two or three, even
 
between its lower tendon ; that of the sartorius, that of the gracilis, and
 
the internal lateral ligament of the knee.
 
 
 
This muscle bends the leg and turns it a little inward ; when it acts
 
in an opposite direction it draws the pelvis and the trunk backward,
 
and bends them with the thigh in the same direction.
 
 
 
B. SEMIMEMBRANOSUS.
 
 
 
§ 1233. The semimembranosus muscle, Ischio-poplili-tibial, Ch. (AT.
 
semimembranosus ), follows a direction to a certain exent directly opposite to that of the preceding. Of the three flexors this arises farther
 
forward, upward, and outward from the outer part of the sciatic tuberosity by a very long, strong, broad, and perfectly distinct tendon, which
 
gradually enlarges and becomes thinner as it descends to the centre of
 
the thigh and to the end of the fleshy belly, to which it is united by an
 
edge oblique from within outward. This belly is elongated, rounded,
 
thicker, but shorter than that of the semitendinosus, and is formed of an
 
internal and an external layer of fibres which are turned upward
 
towards each other, and are attached by radiations to the upper tendon.
 
This latter exists only on the outer face of the upper part of the muscle ;
 
but from its centre to its lower end, where it appears externally as a
 
narrow band, it penetrates deeply inward to the centre of its substance.
 
The lower tendon, which proceeds nearly to the centre of the muscle
 
on its anterior face and on its inner edge, passes on the outer face of
 
the inner condyle of the femur, between it and the semitendinosus
 
 
 
 
 
MÏ0L0GT.
 
 
 
 
 
157
 
 
 
 
 
musclej and is inserted to the inner part of the inner condyle of the
 
tibia, after passing freely a short distance.
 
 
 
A mucous bursa exists between the upper tendon and the quadratus
 
femoris or the adductor magnus. Sometimes there are two. Another
 
is found between the lower tendon, the upper internal head of the gastrocnemius and the capsular ligament of the knee. This bursa often
 
encloses another which is smaller, and adheres very intimately to the
 
tendon of the semimembranosus muscle.
 
 
 
The action of this muscle is the same as that of the preceding.
 
 
 
II. BICEPS FEMORIS.
 
 
 
§ 1234. The biceps femoris muscle, Ischio-femoro-peronier, Ch. (JVJT.
 
flexor cruris externus , s .fibularis, s. biceps femoris ), arises above by
 
two separate heads, which are attached below by a common tendon.
 
 
 
The long head arises from the posterior face of the sciatic tuberosity
 
by a short but firm tendon, which is inserted between the two preceding
 
muscles. A short distance from its upper extremity this tendon begins
 
to receive the fasciculi of the fleshy belly, and descends along its inner
 
edge. The belly descends at first in a straight line, behind and at the
 
side of the upper part of the semimembranosus muscle ; but it then
 
goes outward, passes over the adductor magnus, and thus arrives at
 
the outside of the thigh.
 
 
 
The short head is much smaller, and its form is an oblong square.
 
It arises by very short tendinous fibres from the central two fourths
 
of the outer lip of the linea aspera, directly at the side of the adductor
 
magnus, goes obliquely downward, and is attached tothe inner face of
 
the lower tendon of the long head, from the lower fourth of the thigh
 
to near its lower end.
 
 
 
The common inferior tendon, which goes nearly to the centre of the
 
large belly, on its posterior face, descends on the outer face of the outer
 
condyle of the femur, and is inserted at -the top of the head of the
 
fibula, where there is a mucous bursa between it and the external
 
lateral ligament of the knee.
 
 
 
The biceps femoris muscle bends the knee, turns the leg a little outward, extends the pelvis, and inclines it slightly downward and backward.
 
 
 
§ 1235. Sometimes the short head does not exist, a remarkable analogy with animals, in most of which it is deficient. But in other subjects we find a third, which is thinner, and comes sometimes from the
 
sciatic tuberosity, and is attached below the common tendon of the
 
muscle,(l) and sometimes arises from the upper part of the long head,
 
descends on the calf of the leg, and is joined by the lower end to the
 
tendo Achillis ;(2) this deserves to be remarked because the biceps
 
femoris muscle descends very low in the mammalia.
 
 
 
(1) Gantzer, loc. cit., p. 15. — Scenamering', Muskelehre, p. 276.
 
 
 
(2) Kelch, loc. cit., p. 42, no. xxxvi.
 
 
 
 
 
158
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
When this anomaly exists the biceps femoris resembles the normal
 
structure of the biceps flexor cubiti, even as the latter, when it presents
 
a third supernumerary head, represents the anomaly, of which the
 
other sometimes gives an instance.
 
 
 
 
 
ARTICLE FOURTH.
 
 
 
MUSCLES OF THE LEG.
 
 
 
§ 1236. The muscles of the leg occupy its posterior, external, and
 
anterior faces ; but they leave the internal loose, so that on this side
 
the tibia is covered only by the skin. Most of them are attached, by
 
their upper extremities, to the bones of the leg, and by their lowrnr, to those
 
of the feet as far as the toes. Some, however, come from the lower
 
part of the thigh, their lower extremities are inserted in the bones of
 
the leg.
 
 
 
I. POSTERIOR MUSCLES.
 
 
 
§ 1 237. The posterior muscles of the leg form two layers, a superficial and a deep layer.
 
 
 
I. SUPERFICIAL LAYER.
 
 
 
§ 1238. The superficial layer of the posterior muscles of the leg is
 
composed of two muscles, the triceps suræ and the plantaris.
 
 
 
A. TRICEPS SUBS.
 
 
 
§ 1239. The triceps suræ muscle {JM. triceps suræ , s. gemelli cum
 
soleo) is extremely strong, and forms most of the muscular mass of the
 
leg ; it deserves to be considered as a separate muscle with three heads,
 
since these heads, although entirely separated above, are all attached
 
below to a common tendon.
 
 
 
Two of these heads are in pairs and the third is single. The first
 
two called for this reason the gastrocnemii muscles, Bi-femoro-calcaniens , Ch. (JM. gemelli suræ), are situated at the side of each other.
 
They arise by a short, broad, but thin tendon, which terminates above
 
by a semicircular convex edge from the femur, above the upper edge
 
of the posterior face of its inner and outer condyle.
 
 
 
These two bellies are triangular and much narrower above than
 
below. Above there is an interval of about four inches, which is filled
 
by an abundant and very loose cellular tissue and also by the vessels
 
and the nerves of the leg. Their fibres converge from above downward
 
and meet the common tendon a little above the centre of the whole
 
length of the muscle. The upper tendon, which is expanded along
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
159
 
 
 
 
 
the external edge and the posterior face, gradually becomes thinner
 
and descends almost to the lower extremity of the fleshy belly. The
 
latter terminates below in a rounded edge ; so that the two bellies unite
 
and form a waved line, very concave in its central part. The inner
 
belly is much stronger and descends much lower than the outer. The
 
lower tendon, in which the two fleshy bellies are inserted, arises far
 
above their anterior face, that which corresponds to the posterior face
 
of the bones of the leg, from the union of the two bellies to the centre
 
of their common lower edge : it forms a broad canal, through which
 
• pass the branches of the nerves and vessels which descend on the
 
posterior face of the loose portion of the common tendon.
 
 
 
The third belly, called also the solans muscle, Tibio-calcanien, Ch.,
 
is much stronger than the two preceding. It is situated below and
 
before them.
 
 
 
It arises by its upper edge, which is fleshy, serrated, and oblique
 
downward and inward, from the posterior part of the head of the
 
fibula, from the lower edge of the poplitæus muscle, and from the posterior edge of the tibia. Its lower edge and a part of its anterior face
 
arise for a considerable distance above from the posterior face and below
 
from the inner edge of the tibia. Finally, its outer edge comes from
 
the upper part of the posterior face and from the outer edge of the
 
fibula.
 
 
 
Its posterior and upper fasciculi go directly downward. The anterior and inferior of the two sides meet each other below and are attached
 
to the anterior face of the common tendon, covering its anterior face to
 
some inches above its insertion, gradually becoming thinner and narrower, so that this belly consequently occupies nearly all the leg, and
 
descends very much lower than its centre.
 
 
 
The tendons by which the two lateral edges of this muscle arise
 
from the fibula and the tibia gradually enlarge, descend on the anterior
 
edge and on the posterior face, and do not stop except at some’inches
 
above the lower end of this fleshy belly. Hence most of the latter is
 
enclosed between two aponeurotic expansions.
 
 
 
The common inferior tendon, called the Achilles tendon ( tendo
 
Achillis ), from its power, is slightly covered above and behind by the
 
two posterior bellies and before by the third belly. A little above the
 
lower edge of the posterior bellies it divides into an anterior and a posterior tendinous layer. The latter reascends on the anterior face of the
 
gastrocnemius in the manner mentioned above : the other covers the
 
posterior face almost to the upper edge, gradually becoming thinner.
 
 
 
The tendon, considered as a whole, contracts very much from above
 
downward, and also becomes thicker, and is attached by a very narrow
 
edge to the upper part of the posterior face of the tubercle of the calcanéum, between which and its anterior face we find a considerable
 
mucous bursa above its insertion.
 
 
 
The triceps extends the foot in raising the heel : hence why it acts
 
principally in standing on the toes and other similar circumstances.
 
 
 
 
 
160
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
When the foot is fixed, the two upper heads bend the knee and r draw
 
the thigh backward and downward. The lower head, when it contracts toward the heel, extends the foot, because it carries the leg downward.
 
 
 
This muscle corresponds to the supinators and to the pronator quadratus of the fore-arm : the two superficial heads represent the supinators and the deep head is analogous to the pronator.
 
 
 
B. PLANTABIS.
 
 
 
§ 1240. The plantaris muscle, Petit femoro-calcanien, Ch., arises by
 
a short tendon from the posterior face of the external condyle of the
 
femur, from the external head of the gastrocnemius muscle, to which it
 
is united, and from the posterior wall of the synovial capsule. Proceeding directly behind the capsule, it goes inward and downward and
 
even becomes a long, thin, and flat tendon, which descends along the
 
inner edge of the tendo Achillis, unites with it below, and disappears in
 
the cellular tissue on the inner face of the calcanéum to arrive at the
 
tendinous expansion of the sole of the foot.
 
 
 
This muscle has no very manifest action. We see in it only a rudiment of that which is much more developed in some mammalia and an
 
imperfect imitation of the palmaris brevis of the hand.
 
 
 
§ 1241. It is often deficient and much more frequently than the
 
palmaris.(l)
 
 
 
II. DEEP LAYER.
 
 
 
§ 1242. The deep layer of the posterior muscles of the leg is composed of the poplitæus, the tibialis posticus, the flexor longus digitorum
 
communis, and the flexor longus pollicis proprius.
 
 
 
A. POPLITÆUS.
 
 
 
§ 1243. The poplitæus muscle, Femoro-popliti-tibial, Ch. (J\I. poplitœus , s. sub poplitæus), is a triangular muscle, which arises from the
 
inferior and posterior part of the outer face of the external condyle of
 
the femur. It is formed of oblique fibres, becomes broader from without
 
inward, and is attached to the upper part of the posterior face of the
 
tibia. It is intimately connected, especially at its upper and outer
 
part, with the posterior wall of the synovial capsule of the knee. We
 
find a mucous bursa between it and the external condyle of the femur
 
on one side, the external semilunar cartilage and the capsular ligament on the other.
 
 
 
(1) Our observations authorize us to assert that Gantzer mistakes in stating that
 
the plantaris is more constant than the palmaris (toe. cit., p. 4).
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
161
 
 
 
 
 
This muscle corresponds to the pronator teres of the fore-arm.
 
 
 
It turns the leg a little inward, draws the outer semilunar cartilage
 
outward and backward, and contributes to bend the knee.
 
 
 
§ 1244. Sometimes it is double.(l)
 
 
 
S. TIBIALIS POSTICUS.
 
 
 
§ 1245. The tibialis posticus muscle, Tibio-sous-tarsien, Ch. (AI.
 
tibialis , s. tibiœus posticus , s. nauticus ), arises between the extensor
 
digitorum communis longus and the flexor longus pollicis pedis
 
(§ 1248). It is the longest of the three muscles of the deep-seated
 
lajmr and is penniform. It arises in its whole length from most of the
 
posterior face of the interosseous ligament and from the inner face of
 
the fibula ; some fibres of its upper part arise also from the outer part
 
of the posterior face of the tibia.
 
 
 
Even as in the two long flexors of the toes, the two layers of fibres
 
are attached to a very strong tendon, which descends inward and forward, is contained within the posterior and fibro-cartilaginous groove of
 
the internal malleolus, thence passes into an analogous groove hollowed
 
along the upper part of the inner face of the astragalus, and thus goes
 
to the inner and lower face of the sole of the foot, opposite thd anterior
 
part of the inner face of the astragalus. Its tendon incloses a rounded
 
sesamoid bone and divides into two slips : the internal is shorter, the
 
inferior is longer.
 
 
 
The first is single and is attached to the inner edge of the scaphoid
 
bone. The second divides into several bands, which are inserted in the
 
lower face of the scaphoid, the cuboid, and the three cuneiform bones,
 
at the same time that they blend with the aponeurotic expansion of the
 
sole of the foot and with the tendon of the peroneus longus.
 
 
 
The tendon of this muscle is surrounded with a mucous sheath where
 
it arrives at the sole of the foot.
 
 
 
This muscle corresponds to the radialis internus muscle (§ 1149).
 
 
 
It extends the foot, turns its inner edge a little upward, and the sole
 
inward ; it also extends the thigh and draws it backward.
 
 
 
C. FLEXOR LONGUS DIGITORUM COMMUNIS.
 
 
 
§ 1246. The flexor longus digitorum communis muscle, Tibio-plialangettien , Ch., (AI. flexor digitorum communis longus , s. perforons, s.
 
profundus ), is a thin, elongated, and penniform muscle ; it arises from
 
the summit of the anterior face of the tibia, except its upper part, which
 
is covered by the poplitæus. The fasciculi, by which it arises, and
 
which converge downward are inserted in a strong tendon below, which
 
ascends almost to the upper extremity of the muscle and proceeds along
 
the inner edge. This tendon approaches the surface, descends on the
 
 
 
 
 
(1) Fabricius, De motu loculi animalium, in Op., p. 359.
 
 
 
Vol. II. 21
 
 
 
 
 
162
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
posterior face of the tibia, goes to the inner face of the tarsus, and enters
 
a fibro-cartilaginous furrow which exists along the upper part of the
 
inner face of the astragalus, and is there kept in its position by a tendinous sheath, and thus goes forward. After leaving this point it turns
 
outward, is covered by the posterior head of the abductor pollicis pedis
 
muscle, on which it continues to go forward, and soon divides into fouibands, which go in their turn on the flexor digitorum brevis, which
 
is consequently covered by it.
 
 
 
At the place where the tendon of the flexor longus muscle passes on
 
the flexor brevis, and before it divides into four bands, we see a small
 
muscle attached to its external and inferior part. The form of this
 
muscle is an oblong square. It may be called the small or accessory
 
head of the flexor longus communis {accessorius perf or antis).
 
 
 
This small head, which is covered on all sides by the flexor communis digitorum brevis, arises by two slips, the posterior or external, which
 
is longer and stronger and comes from the external anterior tuberosity
 
of the calcanéum, and the anterior or internal, which is smaller and
 
arises from the superficial calcaneo-cuboid ligament (§ 982). Its fibres
 
are oblique. It goes forward and inward, and not only is it fitted by
 
its inner edge to the tendon of the flexor digitorum longus, but contributes much by its anterior tendons to form those of this muscle.
 
 
 
The small head principally forms almost the whole tendon of the
 
second toe. Most usually this tendon is not at all derived from that of
 
the slip of the common flexor, but only from the short head and from
 
the tendon of the extensor longus proprius pollicis, with which the centre
 
of the flexor communis communicates near the anterior extremity of
 
the calcanéum.
 
 
 
The tendons of this muscle have the same relation to those of the
 
short flexor as those of the flexor digitorum sublimis have with those of
 
the flexor profundus. They are situated upon them, perforate them
 
above the second phalanx of the toes, enlarge a little, and are attached
 
to the posterior part of the lower face of the third phalanges.
 
 
 
It is surrounded by a mucous sheath in the place where its tendon
 
passes at the side of the fibula and of the calcanéum. A second envelops this tendon and that of the flexor longus pollicis proprius at the
 
posterior extremity of the sole of the foot.
 
 
 
The tendon it gives to each toe and that of the flexor minimi digiti
 
proprius are surrounded with a proper mucous sheath.
 
 
 
This muscle bends the third phalanx of the toes and brings the leg
 
backward.
 
 
 
§ 1247. Sometimes it is furnished with a fifth tendon, which replaces
 
the fourth of the flexor digitorum brevis, which is then deficient. This
 
tendon proceeds along the inner edge of the fourth tendon of the flexor
 
longus, and divides to allow the latter to pass, and consequently presents the same arrangement as the flexor sublimis.(l) This formation
 
 
 
 
 
(1) Brugnone, loc. cit., p. 176.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
163
 
 
 
 
 
evidently resembles that of the apes, in which the tendons of the flexor
 
sublimis and flexor profundus are so blended that they are distinguished
 
from each other with difficulty.
 
 
 
D. FLEXOR LONQUS POLLICIS FKOPHIUS.
 
 
 
§ 1248. The flexor longus pollicis proprius muscle, Peroneo-sousphalangettien du pouce, Ch. (JVI. flexor hallucis longus), is shorter but
 
much stronger than the preceding. It arises by an internal and an
 
external layer of fibres, which converge downward and proceed by
 
fleshy fibres from almost all the lower half of the posterior face and
 
from the outer edge of the fibula, excepting only its lowest portion.
 
These two orders of fibres are inserted in a strong lower tendon, which
 
mostly remains concealed in the midst of the muscular substance and
 
becomes entirely loose only when its fleshy fibres cease. This tendon
 
goes obliquely from without inward and from behind forward, and thus
 
comes on the inside of the tarsus, whence it goes forward along a fibrocartilaginous groove, which exists at the upper part of the inner face of
 
the calcanéum, directly below the upper edge of this bone, and where
 
it is retained by a special sheath. It is covered by the outer slip of the
 
posterior head of the abductor pollicis pedis muscle and directly by
 
the tendon of the flexor communis digitorum longus which is nearer
 
the surface, and is consequently situated beneath it. It crosses the
 
direction of the latter and sends to it a very strong tendon, which unites
 
principally to that of the second toe.
 
 
 
We may justly say that the tendon of the flexor longus pollicis proprius muscle divides into two slips where it passes under the abductor
 
pollicis pedis, an external for the second toe and an internal for the
 
large toe. The latter is the strongest ; it goes inward and forward
 
directly at the side of the abductor pollicis pedis, is situated outward
 
before it, and is partly covered by it. At the anterior end of thé metatarsal bone of the large toe it enlarges a little, at the same time becomes thinner, and is attached to the posterior part of the lower face
 
of the second phalanx of the large toe.
 
 
 
This muscle corresponds to the flexor longus digitorum communis
 
in its course and in its attachment to the anterior phalanx of its toe.
 
 
 
There is in fact a short flexor of the large toe ; but this muscle has
 
no perforated tendon which is attached to the posterior phalanx. On
 
the contrary, we sometimes see an arrangement analogous to that of
 
the tendons of the flexor brevis perforatus. In fact a strong but narrower tendon, which however gradually enlarges as it advances, extends from the head of the first metatarsal bone to the posterior end of
 
the second phalanx, over the tendon of the flexor longus : this tendon
 
is firmly attached in its whole extent and breadth of its upper face to
 
the lower face of the phalanges, by a fold of the synovial capsule : it
 
contains a single and transverse sesamoid bone : immediately behind its
 
anterior extremity and below the articulation of the first phalanx with
 
 
 
 
 
164
 
 
 
 
 
DESCRIPTIVE ANAT0MV.
 
 
 
 
 
the second, it is finally attached to the lower face of the first phalanx,
 
directly behind the tendon of the flexor longus.
 
 
 
This tendon which has no muscle, is not found in the other toes ; so
 
that decidedly we should consider it as a rudiment of the flexor longus
 
communis perforatus : it is however but an imperfect rudiment, since it
 
is never perforated, which depends probably on the absence of the
 
second phalanx of the large toe.
 
 
 
The tendon of this muscle is enveloped with a mucous bursa in the
 
canal of the astragalus and os calcis. A second covers its tendon and
 
that of the flexor longus at the posterior part of the sole of the foot. A
 
third incloses its tendon along the metatarsal bone of the first toe.
 
 
 
It flexes the large and small toe.
 
 
 
§ 1249. We sometimes find at the lower part of the posterior face of
 
the leg a small supernumerary muscle, which does not always present
 
exactly the same arrangement. Sometimes it ascends from the calcanéum and from the tendo Achillis, and is attached to the aponeurotic
 
expansion of the leg, acting as its tensor muscle ;(1) so that we may
 
then consider it as a fourth head of the triceps. It sometimes arises
 
from the lower part of the fibula, goes downward, and is then lost
 
around the articulation of the foot. It is sometimes attached to a special bone found in this place, (2) or to the lower face of the calcanéum,
 
or finally to the small head of the flexor longus digitorum communis. (3)
 
 
 
The second anomaly is very probably a repetition of the pronator
 
quadratus of the upper extremity, but it is developed lower toward the
 
foot, in accordance with the same law as that to which the other muscles are subjected, especially the flexors and extensors of the toes.
 
 
 
The first corresponds probably to the palmaris brevis ; the arrangement of the muscle in the upper and lower extremity differ in the same
 
way as the palmaris brevis and the plantaris, as the latter does not
 
arrive at the aponeurotic expansion of the sole of the foot.
 
 
 
II. EXTERNAL MUSCLES.
 
 
 
§ 1250. The external muscles of the leg are the peroneus longus
 
and the peroneus brevis. They extend from the fibula to the outer
 
edge and to the lower face of the foot.
 
 
 
 
 
I. PERONEUS LONGUS.
 
 
 
§ 1251. The peroneus longus muscle, Peroneo-sous-tarsien, Ch. (JM.
 
'peroneus longus, s. primus, s. posticus ), arises from the upper and smaller
 
half of the anterior face, and by fibres which proceed obliquely from
 
above downward and converge. Its upper tendon arises from the outer
 
edge of the fibula and covers the upper and posterior part of this bone.
 
 
 
(1) Mayer in Heymann, loc. cit ., p. 15.
 
 
 
(2) Rosenmüller, loc. cit., p. 8.
 
 
 
(3) Gantzer, loc. cit., p. 15-17.
 
 
 
 
 
JMYOLOGY.
 
 
 
 
 
165
 
 
 
 
 
The lower tendon, which is very long, very strong, flat, and entirely
 
loose from the lower third of the leg, conceals itself partially above this
 
point between the muscular fibres ; so that it entirely disappears externally toward the bottom of the upper third of the leg. But it appears
 
again within the muscle, near its upper extremity, as a semicircular
 
band, which gradually diminishes and to which the fleshy fasciculi are
 
attached outward and inward.
 
 
 
This tendon goes behind and on the outside of that of the peroneus
 
brevis, along the outer and posterior face of the leg, and descends behind the external malleolus across a ligament formed of oblique fibres,
 
within which is a sheath which sends prolongations to it. Arrived at
 
the foot, the tendon winds forward and downward, 'around the outer edge
 
of the cuboid bone, and thus comes on the sole of the foot, where it penetrates ; thence it goes inward, covered by all the muscles of this region
 
and directly by the calcaneo-cuboid ligament, which keeps it in place :
 
then gradually enlarging, it is attached to the lower face of the cuboid
 
bone and also to the lower face of the posterior head of the fifth, also of
 
the fourth and third, and particularly of the second metatarsal bones :
 
it sometimes also reaches the first metatarsal bone and the first cuneiform bone before dividing.
 
 
 
At the place where the friction of the tendon is the greatest, especially opposite the external malleolus, the tuberosity of the calcanéum,
 
and the cuboid bone, sometimes also in its plantar portion, we find sesamoid bones or cartilages, the third of which is the largest, while the
 
first is very small and often scarcely perceptible.
 
 
 
There is also a considerable mucous bursa where the tendon of the
 
muscle descends on the outer malleolus and astragalus : this bursa envelops it and also the tendon of the following muscle. We find another
 
below, which extends to the plantar face.
 
 
 
The peroneus longus muscle extends the tibio-tarsal articulation and
 
chaws the foot backward and the leg downward : it also turns the foot,
 
making its outer edge the upper and the plantar face look upward.
 
 
 
It corresponds to the flexor carpi ulnaris of the fore-arm.
 
 
 
II. PEEONEUS EEEVIS.
 
 
 
§ 1252. The peroneus brevis muscle, Grand peroneo-sus-metatarsien,
 
Ch. (JV[. peroneus, s.fibidaris brevis, s. anticus, s. secundus, s. médius,
 
s. semifibulœus ), is an elongated muscle, which terminates above in a
 
point and is formed of two layers of fibres ; those of the anterior layer
 
go from before backward and those of the posterior go from behind forward, These two layers converge toward the base : they arise from
 
the second fourth of the anterior face and from the posterior edge of
 
the fibula to near the outer malleolus.
 
 
 
The lower tendon, which is long, strong, and flat, extends within
 
the muscle, and like that of the preceding ascends almost to its upper
 
extremity. It becomes visible externally sooner than that of the pero
 
 
 
166
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
neus longus, and descends between the fibres of the muscle to arrive
 
 
 
at its outer face.
 
 
 
Once disengaged it goes before that of the peroneus longus, behind
 
the outer malleolus, and is retained in the groove which exists there by
 
a ligament, common to it and the preceding muscle. This ligament,
 
called the retinaculum musculorum peronœorum, extends from the anterior to the posterior edge of the groove like a bridge. The tendon
 
having thus reached the upper face of the foot goes forward, enlarging
 
along its anterior edge. Near the base of the fifth metatarsal bone it
 
usually divides into two slips, the outer of which is attached to the
 
tuberosity of this bone while the inner is longer, subdivided likewise into
 
two parts, one of which is attached to the centre of the upper face of
 
its body ; the second is inserted partly in the outer edge of the fourth
 
tendon of the extensor and partly on the posterior face of the fourth
 
external interosseous muscle.
 
 
 
Besides the common mucous bursa (§ 1229) the tendon of this muscle has a special bursa situated lower on the outer edge of the foot,
 
and which surrounds it.
 
 
 
The peroneus brevis muscle acts like the preceding ; it flexes the
 
tibio-tarsal articulation, consequently carries the foot upward, and
 
depresses the leg ; it also turns the sole of the foot outward and its
 
outer edge upward, but less so than the peroneus longus.
 
 
 
It corresponds to the extensor carpi ulnaris, and paitially also to the
 
extensor brevis minimi digiti.
 
 
 
§ 1253. It is sometimes double.
 
 
 
III. ANTERIOR MUSCLES.
 
 
 
§ 1254. On the anterior faco of the leg we find one after another
 
the extensor longus digitorum communis, the extensor longus hallucis
 
proprius, and the tibialis anticus.
 
 
 
I. EXTENSOR LONGUS DIGITORUM COMMUNIS.
 
 
 
§ 1255. The extensor longus digitorum communis muscle, Peroneosus-p halange men commun , Ch. ( AI. extensor digitorum communis longus ), is a very long muscle, occupying almost all the leg. Its fibres
 
descend obliquely from behind forward. It arises above from the outer
 
face of the head of the tibia, and, in the rest of its course, from the
 
anterior face of the interosseous ligament, and also from the anterior
 
edge of the fibula. It is attached to the tendon which commences
 
near its upper extremity and which descends on its anterior edge.
 
 
 
This tendon generally divides below the crucial ligament of the foot
 
into five slips, which separate from each other. The outer is the
 
shortest, and is inserted into the posterior extremity of the upper face
 
of the fifth, and sometimes also of the fourth, metatarsal bone. This
 
slip is sometimes connected with a special fleshy belly entirely distinct
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
167
 
 
 
 
 
from the extensor longus, but which most generally forms only the lower
 
part, and which is called the small or the peroneus iertius muscle. It
 
is not unfrequently deficient, and is then replaced to a certain extent by
 
the inner part of the tendon of the peroneus brevis muscle : it
 
also frequently forms a small special tendon which is sometimes
 
attached forward to the metatarsal bone, and sometimes unites either
 
to the fourth external interosseous muscle or to the tendon sent by the
 
common extensor to the fifth toe. The four other slips go obliquely
 
forward and outward ; they are attached to the dorsal faces of the
 
second, third, fourth, and fifth toes. Arrived at the base of the posterior phalanges they become broader and a little thinner, and give off
 
also, the fourth outwardly, the other three inwardly, a thin triangular
 
prolongation, formed of perpendicular fibres, which go downward, and
 
are attached partly to the base of the first phalanx, and are partly
 
blended with the tendon of the interosseous muscles.
 
 
 
This tendon sometimes assumes the nature of cartilage when passing over the synovial capsule of the first phalangean articulation. On
 
the articulation between the second and third it enlarges or divides
 
more or less completely into two lateral slips, which converge forward,
 
and after muting are attached to the upper face of the third phalanx,
 
directly before its posterior edge.
 
 
 
We find an oblong mucous bursa on the articulation of the foot,
 
between the tendon of this muscle and the capsular ligament.
 
 
 
The extensor digitorum communis longus raises the four smaller
 
toes, extends them, and with the peroneus brevis muscle, bends the tibiotarsal joint, and thus raises the foot or draws the leg forward and downward.
 
 
 
This muscle and the preceding act principally in standing on the
 
toes, because they fix the leg.
 
 
 
The extensor digitorum communis longus corresponds to the common extensor of the fingers. The proper extensor of the little finger
 
is represented by the peroneus tertius, and when that is deficient by a
 
part of the peroneus brevis.
 
 
 
This analogy becomes still more evident when the portion of the
 
flexor longus belonging to the little toe, and the peroneus tertius muscle,
 
are entirely separated from the rest of the muscle.(l)
 
 
 
II. EXTENSOR LONGUS HALLUCIS EROPRIUS.
 
 
 
§ 1256. The extensor longus hallucis proprius muscle, Peroneo susphalangettien du pouce , Ch., is a thin and semipenniform muscle, which
 
arises, by fleshy fibres, from the lower two thirds of the inner face of
 
the fibula, and from the anterior face of the interosseous ligament. It
 
also receives below some fibres from the outer face of the tibia.
 
 
 
Its fasciculi are attached to a tendon which proceeds along the
 
anterior edge of the muscle, gradually becomes broader, passes across
 
a particular groove of the crucial ligament of the back of the foot, goes
 
 
 
 
 
(1) Brugnone, loc. cit . — We have seen it several times.
 
 
 
 
 
168
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
inward and forward along the inner edge of the tarsus, and is attached
 
to the upper face of the unguæal phalanx of the first toe.
 
 
 
On the back of the tibio-tarsal articulation the tendon of this muscle
 
is inclosed in a special mucous sheath.
 
 
 
It raises all the first toe.
 
 
 
§ 1257. This muscle is often more or less completely double. In
 
this case we sometimes find another which is smaller, and which arises
 
more externally from the fibula, and from the anterior face of the interosseous ligament, goes to the large toe, and unites to the tendon of this
 
muscle, or is attached to the first metatarsal bone, or finally loses
 
itself in the cellular tissue. Sometimes and most generally another
 
smaller tendon is detached, even in the leg, from the inner edge of the
 
normal tendon, which is inserted in the tibial side of the two phalanges.
 
These anomalies are important because they approximate the formation of the proper extensor of the large toe to that of the proper extensor of the thumb ; so too on the other hand, the deficiency of the short
 
extensor of the thumb, or its blending with the large, approximates the
 
formation of the hand to that of the foot.
 
 
 
III. TIBIALIS ANTICUS.
 
 
 
§ 1258. The tibialis anticus muscle, Tibio-sus-tarsien, Ch. (JVT. tibialis, s. tibiczus anticus, s. catena: musculus, s. hippicus), is the strongest
 
of the three anterior muscles of the leg ; it arises directly at the side of
 
the peroneus longus muscle, and is covered in this place by a broad
 
tendon, which expands on its anterior face from the lower face of the
 
outer part of the head of the tibia, and still lower from the outer face
 
of this bone, nearly to its lower third, so that its fibres gradually come
 
only from the most posterior portion, and even the inner edge of this
 
face in all its course. At the same time it receives some which arise
 
from the periosteum. All these fibres, which go obliquely Torward,
 
are attached to an anterior tendon, which is loose only in a very small
 
point of its extent downward, but which extend within the muscle
 
even beyond its centre. This tendon, which is very strong, descends
 
obliquely inward, passes on the anterior face of the tibio-tarsal articulation, comes upon the inner edge of the foot, where it is retained by a
 
ligamentous band, oblique downward and backward, which extends
 
from the scaphoid to the first cuneiform bone, and is finally attached
 
by two short slips to the inner part of the lower face of -the large cuneiform bone, and also to the base of the metatarsal bone of the large toe.
 
 
 
Opposite the articulation of the foot its tendon is enveloped in a
 
mucous sheath.
 
 
 
It raises the foot, turns it on its axis, so that its sole looks inward
 
and its inner edge upward.
 
 
 
It corresponds to the radiales muscles of the hand.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
169
 
 
 
 
 
ARTICLE FIFTH.
 
 
 
MUSCLES OF THE FOOT.
 
 
 
§ 1259. The muscles of the foot arise from the tarsus and metatarsus,
 
and are all attached to the phalanges of the toes. They are situated
 
on the back of the foot, on its sole, on its internal and external edges.
 
Some are common to several toes, others belong exclusively to some
 
of them, namely to the large and small toes. The latter are only
 
repetitions of those which are divided between several of them.
 
 
 
I. MUSCLES OF THE BACK OF THE FOOT.
 
 
 
§ 1260. Besides the tendons of the extensor digitorum communis
 
longus and of the two peronei muscles, we find also on the back of
 
the foot the extensor communis digitorum brevis.
 
 
 
EXTENSOR COMMUNIS DIGITORUM BREVIS.
 
 
 
§ 1261. The extensor communis digitorum brevis muscle, Calcaneosus-phalangettien commun, Ch. ( JW, . extensor digitorum pedis communis
 
brevis, s. pediceus externus ), is a flat muscle, formed of four elongated and
 
rounded bellies, which arises from the back of the anterior process of
 
the calcanéum, goes forward and inward, its bellies separating from
 
each other, and is attached -by four tendons to the four inner toes.
 
These tendons in their course on the metatarsus cross those of the
 
extensor communis digitorum longus, but on the toes they are situated
 
on the outside of them. The outer three are very intimately blended,
 
by their internal edge, with the outer edge of the tendons of the
 
extensor longus, and consequently form their outer half ; hut the
 
most internal, that which goes to the great toe, does not unite to the
 
corresponding tendon of the flexor longus, but is attached below it to
 
the posterior edge of the back of the first phalanx of the large toe.
 
 
 
This muscle extends the four inner toes and directs them a little
 
outward.
 
 
 
§ 1262. Often and even most generally its inner belly is separated
 
much more from the others than the latter are from each other. Very
 
frequently it forms an entirely distinct muscle, which deserves to be
 
noted because of the more striking resemblance established between
 
the upper and lower extremities by this peculiarity. Sometimes the
 
other bellies and even all are entirely detached from each other, a
 
curious analogy with what exists in birds. Again, the extensor brevis
 
often presents supernumerary bellies. Most commonly a small fleshy
 
fasciculus exists between the internal and what is commonly called
 
the second ; its tendon is attached either to the second metatarsal bone
 
or to the tibial face of the second toe. This accessory muscle, men
 
Vol. II. 22
 
 
 
 
 
170
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
tioned by Albinus,(l) and which we have often seen, is curious, as it
 
must evidently be considered as a repetition of the indicator muscle.
 
 
 
The second belly is also sometimes divided at its anterior extremity
 
into two fasciculi, or sends two tendons to the second toe.
 
 
 
The tendons of the third and fourth bellies are often divided, so that
 
there is for the third toe an extensor muscle or at least a tendon ; this
 
arrangement resembles the doubling of the proper extensor of the
 
index finger in the hand for a proper extensor of the third finger.
 
 
 
After this anomaly the one most frequently found consists in the
 
presence of a small special belly for the fifth toe. We have also seen
 
this several times, and it is interesting as an analogy either with the
 
apes(2) or with the extensor proprius minimi digiti.
 
 
 
II. MUSCLES OF THE SOLE OF THE FOOT.
 
 
 
§ 1203. Most of the muscles of this part of the lower extremity are
 
found in the sole of the foot.(3) In fact, besides the short head of the
 
extensor digitorum communis already described (§ 1245), we find the
 
flexor communis digitorum brevis, the adductor and flexor of the large
 
and little toes, the adductor hallucis, the lumbricales, and the interossei
 
muscles.
 
 
 
The adductor hallucis occupies the inner edge of the foot and that
 
of the little toe the outer edge. A great part however of these muscles
 
project likewise in the sole, so that it is best to study them at the same
 
time as the other muscles of the toes, to which they belong, and to
 
consider them as the lower muscles of the foot.
 
 
 
We shall describe first the common muscles, next the special muscles : first, however, their common aponeurosis.
 
 
 
I. PLANTAR APONEUnOSIS.
 
 
 
§ 1264. The plantar aponeurosis (aponeurosis plantaris) is a very
 
firm tendinous layer, formed of longitudinal fibres, which arises from
 
the lower face of the tuberosity of the calcanéum, directly under the
 
skin, with which it is intimately connected. Thence it goes forward,
 
where it enlarges very much. Arrived at the anterior edge of the
 
metatarsus it divides into five slips, which correspond to the five toes,
 
and which are attached to each other by transverse fibres.
 
 
 
This aponeurosis protects and fixes the muscles of the sole of the
 
foot, and at the same time increases the surfaces of insertion of several.
 
 
 
 
 
(1) Hist, muse ., p. 602.
 
 
 
(2) Meckel, Beytrâge zur vergleichenden Anatomie, vol. ii. part i.
 
 
 
(2) A. F. Walther, Tractationes de articules , ligamentis et musculis incessu dirigendis supplemcnlvm tahulamquc novam plantœ humani pedis exhibens, Leipsic,
 
1731.— D. C. de Courcelles, Icônes musculorum plantœ pedis, sorumque descriptio,
 
Au-isterdam, 1760.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
171
 
 
 
 
 
II. COMMON MUSCLES OF THE SOLE OF THE FOOT.
 
 
 
a. Flexor dig-itorum pedis communis brevis.
 
 
 
§ 1265. The flexor communis digitorum brevis muscle, Calcaneosous-phalanginicn commun , Ch. (JV/. flexor digitorum pedis communis
 
brevis , s. perforahis , s. sublimis, s. pediœus intermis ), is elongated,
 
quadrilateral, thicker behind, and broader but thinner before. It arises
 
by very strong tendinous fibres, which extend on a considerable portion
 
of its lower face from the lower face of the tuberosity of the calcanéum,
 
and by fleshy fibres by almost all its lower face, from the upper
 
face of the plantar aponeurosis, to which its posterior tendon also
 
adheres. Posteriorly it is very intimately united internally with the
 
outer edge of the adductor pollicis, and above with the short head of
 
the extensor communis digitorum longus. Nearly in the centre of the
 
sole of the foot it divides into four very short fleshy fasciculi, which soon
 
become as many single tendons. The latter are attached to the
 
second, third, fourth, and fifth toes. They cover those of the extensor
 
longus and are much smaller. They are arranged in the same manner
 
anteriorly as those of the extensor digitorum sublimis. In fact a
 
rhomboidal fissure begins a little before the posterior extremity of the
 
first phalanx, which extends to before the centre of this bone. The
 
tendons of the extensor communis digitorum profundus pass through
 
these fissures.
 
 
 
The two halves of the tendon which pass through this division
 
unite for a short extent ; then again separate, enlarge and diverge from
 
before backward, and are separately attached by straight edges to
 
the centre of the lower face of the second phalanx.
 
 
 
Each tendon of this muscle is attached with the corresponding
 
tendon of the flexor longus, to the lower face of the toes by synovial
 
and fibrous ligaments, exactly like those which retain the tendons of
 
the flexor sublimis and profundus of the fingers.
 
 
 
This muscle flexes the first and second phalanges of the four outer
 
toes.
 
 
 
§ 1266. The fourth tendon is sometimes deficient, and then it is
 
often but not always replaced by a tendon of the flexor longus. In
 
some subjects there seems to be an antagonism between the short
 
extensor and the short flexor of the toes ; for we have sometimes found
 
in this case the number of tendons of the second is greater than usual.
 
 
 
Sometimes also another portion of the muscle is deficient ; it is
 
usually the most internal or the most external. It is then replaced by
 
other fasciculi which come from the flexor of the large and that of the
 
little toe, which reminds us of the insulation of the internal head of
 
this muscle hi apes, and the disappearance of the short common flexor
 
as a separate muscle in all the other mammalia and in all birds.
 
 
 
 
 
172
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
b. Lumbricales.
 
 
 
§ 1267. The lumbricales muscles, Planti-sous-phalangiens , Ch.,
 
correspond to those of the hand in number, form, and situation. They
 
arise by fleshy fibres from the tendons of the flexor digitorum longus,
 
and are attached, partly by short tendons, to the posterior head of the
 
first phalanx of the four outer toes, and partly by thin tendinous expansions, to the tendons of the extensor digitorum longus.
 
 
 
c. Interossei.
 
 
 
§ 1268. We find in the foot as in the hand seven interossei muscles,
 
Æetatarso-phalangiens latéraux , Ch. (JVf. interossei), which fill the
 
intervals between the metatarsal bones. They arise from the posterior
 
part and from the lateral faces of these bones, and their anterior tendons
 
blend below with those of the extensor communis.
 
 
 
We distinguish them into external and internal. The first are four
 
and the second three in number.
 
 
 
a. External interossei.
 
 
 
§ 1269. The upper and external or dorsal interossei muscles (JM.
 
interossei externi , s. superiores, s. dorsales) are situated directly below
 
the extensor communis digitorum brevis, in the first, second, third, and
 
fourth interosseous spaces.
 
 
 
The first, which is the most internal, differs from the other three in
 
its form and arrangement. In fact it comes only from the tibial side
 
of the second metatarsal bone and is attached forward by a short, broad,
 
and flat tendon to the inside of the first phalanx of the second toe.
 
 
 
It is however almost always divided into tw r o heads, the upper of
 
which is longer and much thinner than the lower.
 
 
 
The second, third, and fourth have two heads each, which are inserted by short tendons on the outer or fibular side of the first phalanx
 
of the second, third, and fourth toes.
 
 
 
The outer head is much larger, arises from the posterior part of the
 
inner face of the metatarsal bone, which is placed directly on the outside of the toe to which the tendon is attached, and descends as deeply
 
as the internal, on the side of the sole of the foot. The inner is the
 
smallest, and arises from the posterior part of the outer face of the metatarsal bone of the toe in which its tendon is inserted, and descends a
 
little lower than the preceding. The fibres of these two heads unite at
 
a very acute angle and are implanted in a common tendon.
 
 
 
The first external interosseous muscle brings the first toe inward ;
 
the second, third, and fourth carry the toes to which they are attached
 
outward.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
173
 
 
 
 
 
b. Internal interossei.
 
 
 
§ 1270. The internal, inferior , or plantar interossei muscles (JVf.
 
interossei interni , s. inferiores , s. plantares) are smaller than the external and have only one head. They arise from almost all the posterior
 
part of the inner or tibial face of the third, fourth, and fifth metatarsal
 
bones, and are attached by a considerable tendon to the inner face of
 
the first phalanx of the third, fourth, and fifth toes. This tendon is
 
closely united to the capsule of the metatarso-phalangean articulation,
 
and sends a prolongation to that of the extensor communis.
 
 
 
These muscles direct the third, fourth, and fifth toes inward toward
 
the large toe.
 
 
 
 
 
III. PROPER MUSCLES OP THE TOES.
 
 
 
§ 1271. We may consider as proper muscles those of the large and
 
small toes.
 
 
 
a. Muscles of the large toes,
 
a. Abductor haltucis.
 
 
 
§ 1272. The abductor hallucis muscle, JWetatarso-sous-phalangien
 
du premier orteil , Ch., is the strongest short muscle of this toe. It
 
arises by several slips from the inside of the tarsus and the metatarsus,
 
and is attached to the inside of the large toe. To simplify the description, we may refer these several slips to two heads.
 
 
 
The posterior head, which is the larger, arises by two bands, of
 
which the inferior is longer, from the lower part of the inner side of the
 
tuberosity of the calcanéum, and the upper, which is shorter, from the
 
upper and projecting part of the inner face of the body of the calcanéum.
 
 
 
The anterior head, which is the smaller, arises by three or four distinct slips from the inner and anterior face of the astragalus, scaphoid,
 
the first cuneiform, and first metatarsal bone. The posterior tendon of
 
these two fasciculi covers them from their origin to near their anterior
 
extremity below. The anterior, which is much stronger, begins near
 
the centre of the posterior belly and is situated on its inner side ; so that
 
the fibres of the two bellies which go forward and inward are inserted
 
at acute angles.
 
 
 
This last tendon, after it disappears from the surface, extends very
 
far within the muscle, whence it goes backward and divides into several very considerable slips. Anteriorly, it is sometimes attached by two
 
slips to the lower and inner face of the head of the first metatarsal
 
bone, to the inner face of the capsular ligament of the first metatarso-phalangean articulation, and principally to the inner and lower
 
 
 
 
 
174
 
 
 
 
 
DESCRIPTIVE ANATOMS'.
 
 
 
 
 
part of the base of the first phalanx of the large toe, where it adheres
 
intimately to the flexor digitorum brevis.
 
 
 
This muscle brings the large toe inward and flexes it a little.
 
 
 
b. Flexor brevis pollicis pedis.
 
 
 
§ 1273. The flexor brevis pollicis pedis , Tarso-sous-phalangien du
 
premier orteil, Ch. {JS1. flexor hallucis proprius brevis), is much shorter
 
than the abductor. It arises behind from the tendinous sheath of the
 
peroneus longus, intimately united to the long'head of the adductor of
 
the large toe. Most generally its posterior extremity maybe divided
 
into an external and an internal belly. Thence it goes inward and
 
forward. It is attached by a short tendon, more or less divided, to the
 
posterior part of the lower side of the base of the first phalanx of the
 
large toe. This tendon is generally united to that of the adductor outward ; it contains anteriorly, below the two parts of the head of the
 
first metatarsal bone, two sesamoid bones placed one at the side of the
 
other.
 
 
 
This muscle flexes the first phalanx of the large toe.
 
 
 
 
 
c. Adductor pollicis pedis.
 
 
 
§ 1274. The adductor pollicis pedis muscle, Calcaneo-sous-phalangien du premier orteil , Ch. (JM. adductor hallucis), is a considerable
 
muscle which has two bellies.
 
 
 
The posterior is much stronger than the other and is placed above
 
and outside of the flexor brevis pollicis pedis. It arises from the lower
 
side of the base of the third and fourth and also often of the second metatarsal bone, and from the sheath of the peroneus longus, above the
 
flexor brevis pollicis pedis. Before, on its outer and lower face, are
 
strong tendinous expansions, which unite to give rise to the anterior
 
tendon. This latter is united to the external tendon of the flexor brevis
 
(§ 1212), and is attached to the outer face of the base of the first metatarsal bone.
 
 
 
The anterior head is much smaller and weaker than the posterior,
 
and arises from the lower and inner face of the capsular ligament, between the metatarsal bone and the first phalanx of the fourth and fifth
 
toes, sometimes also from the anterior part of the fifth metatarsal bone.
 
 
 
It goes obliquely forward and inward, directly below the anterior end
 
of the interossei muscles, between these and the tendons of the flexor
 
communis digitorum profundus. It is attached by a thin and short
 
tendon to that of the abductor of the great toe.
 
 
 
 
 
MYOI.OGY.
 
 
 
 
 
175
 
 
 
 
 
b. Muscles of the little toe.
 
a. Abductor minimi digit!.
 
 
 
§ 1275. The abductor minimi digiti muscle, Calcaneo-sous-phalangenien du petit orteil , Ch. (JVf. abductor digiti quinti), is the longer of
 
the two muscles of this appendage, has two bellies like the abductor
 
pollicis pedis ; the posterior belly is greater.
 
 
 
The posterior belly is covered below and behind by a strong aponeurosis, and arises from the posterior and from a little of the anterior part
 
of the lower face of the tuberosity of the calcanéum.
 
 
 
The anterior belly comes from the lower edge of the tuberosity of
 
the fifth toe.
 
 
 
Both are attached outwardly to a broad and strong tendon, which
 
extends far back into the substance of the muscle and which is attached
 
to the outer part of the lower face of the base of the first phalanx.
 
 
 
b. Flexor minimi digiti brevis.
 
 
 
§ 1276. The flexor minimi digiti brevis muscle, Tar so-sous-p hal angien du petit orteil , Ch. (AI. flexor digiti quinti proprius brevis), is
 
much smaller than the preceding. It arises from the inner part of the
 
lower side of the base of the fifth metatarsal bone and from all the lower
 
face of its body. It may almost always be divided into an outer and
 
inner belly. Most frequently also it is attached by two distinct tendons
 
to the inner part of the lower side of the base of the first phalanx.
 
 
 
§ 1277. The muscles of the large and small toes may be referred to
 
the other muscles of the foot, as we have seen those of the thumb and
 
little finger could be to the other muscles of the hand. The abductor
 
pollicis pedis is the first external interosseous muscle, and the posterior
 
belly of the abductor the first internal interosseous muscle. The anterior belly of the latter represents the first lumbricalis. The flexor brevis digitorum pedis muscle corresponds to the flexor digitorum communis. The abductor minimi digiti is the last external interosseous
 
muscle. Finally, the flexor minimi digiti brevis may be considered as
 
belonging to the flexor digitorum communis, because of the slight development of the fourth tendon of the latter in most subjects.
 
 
 
COMPARISON OF THE MUSCLES OF THE DIFFERENT REGIONS OF THE
 
 
 
BODY.
 
 
 
§ 1278. We have already compared the muscles of the different
 
regions of the body with each other in different directions, while describing each one particularly. They also conform to the law that the
 
analogy betweeen the upper and lower halves of the body is more
 
marked than that between the anterior and posterior. In fact we observe, 1st, that many muscles which succeed from above downward
 
 
 
 
 
176
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
arc repetitions of one another, as is evident with those between the
 
vertebrae or between these bones and the head ; 2d, the muscles of the
 
limbs correspond very evidently, and the differences they present, like
 
those between the bones and the ligaments, depend on the greater
 
solidity of the lower limbs and the greater mobility of the upper, either
 
when considered as a whole and in their relations with the trunk, or
 
when viewed in detail and in regard to the relations of their different
 
parts with each other. An abnormal arrangement of the muscles
 
belonging to the two extremities frequently renders their similitude
 
more perfect and more evident than it is generally ; and if we do not
 
err, of all the organic systems, the muscular most frequently presents
 
anomalies in the configuration, which cause an unusual similitude between the anterior and posterior faces of the body and also between its
 
upper and lower portions.
 
 
 
In this respect we often find an anterior sternal muscle, which determines a resemblance between man and animals, and the existence of
 
which is so curious in another respect ; and we not unfrequently find a
 
short head of the biceps flexor cubiti and a short extensor of the middle
 
finger.
 
 
 
So too the muscles of the lower limbs are frequently repetitions of
 
those of the upper. The latter however seem to us more disposed to
 
present assimilating anomalies in their configuration, which probably
 
depends on a general law, amply supported by the vascular system,
 
viz. that anomalies in the pelvic members are more frequent than in
 
the pectoral extremities.
 
 
 
GENERAL REMARKS ON THE MOTIONS OF THE HUMAN BODY.
 
 
 
§ 1279. Having described successively the different organs of locomotion, we must now briefly examine the principal motions(l) which
 
result from their joint action.
 
 
 
We must first, endeavor to prove that the erect •posture on the lower
 
limbs is natural to man.
 
 
 
 
 
A. ERECT POSTURE.
 
 
 
I. OSSEOUS SYSTEM.
 
 
 
§ 1280. We may also point out in this place the conditions which
 
arise from the other organic systems, not yet described, and which refer
 
to the general form of the body, because the osseous system serves as
 
the basis for all the others.
 
 
 
In considering the body from below upward, we discover successively
 
in the osseous system all the conditions which render the erect posture
 
natural to man.
 
 
 
(1) F. Roulin, Recherches théoriques et expérimentales sur le mécanisme des mouvements et des att itudes dans l'homme ; in the Journ. de physiol. e.rp., vol. i. p. 2C9, 301,
 
vol. ii. p. 45, 156, 283.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
177
 
 
 
 
 
1. In the lower extremities.
 
 
 
§ 1281. 1st. The predominance of the bones of the lower over those
 
of the upper extremities.
 
 
 
2d. It is only in the erect posture that the articular surfaces of all the
 
bones are exactly fitted to each other.
 
 
 
3d. The breadth of the foot.
 
 
 
4th. The size of the tarsus and metatarsus in proportion to the toes.
 
 
 
5th. The number and size of the sesamoid bones.
 
 
 
6th. The union of the bones of the leg with the tarsus at a right
 
angle.
 
 
 
7th. The length and the obliquity of the neck of the femur.
 
 
 
8th. The breadth, concavity, and lowness of the iliac bones.
 
 
 
2. In the trunk.
 
 
 
§ 1282. 1st. The lowness, breadth, and curve of the sacrum, and
 
also the curving inward of the coccyx, upon which and also on the
 
arrangement of the iliac bones the peculiar shape of the human pelvis
 
depends, which seems well adapted only for the erect posture.
 
 
 
2d. The breadth and lowness of the vertebrae.
 
 
 
3d. The considerable curve of the ribs, whence results the breadth
 
and convexity of the thorax.
 
 
 
3. In the head.
 
 
 
§ 1283. 1st. The anterior, posterior, and horizontal position of the
 
condyles and foramen magnum of the os occipitis.
 
 
 
2d. The direction of the cavities of the orbits and nose forward in the
 
erect posture and downward in that on the four limbs.
 
 
 
4. In the upper limbs.
 
 
 
§ 1284. 1st. The shortness and feebleness of these members in proportion to the lower.
 
 
 
2d. The forced position of the bones of the fore-arm and of the radiocarpal articulation in walking on all fours,
 
 
 
3d. The mobility of the radius.
 
 
 
4th. The concavity and breadth of the bones of the metacarpus and
 
of the phalanges. These latter circumstances indicate that the bones
 
of the upper extremities are intended to grasp external objects, while
 
the corresponding parts of the lower limbs prove they are designed
 
to support the body.
 
 
 
 
 
VOL. II.
 
 
 
 
 
23
 
 
 
 
 
178
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
II. LIGAMENTOUS SYSTEM.
 
 
 
§ 1285. The peculiarities of the ligamentous system are as follow :
 
 
 
1st. The ligaments of the lower extremities are stronger than those
 
of the upper, and this strength increases progressively from below
 
upward.
 
 
 
2d. The looseness of the cervical ligament, although the head is
 
very much developed, in regard to the occipital foramen which is
 
situated farther forward.
 
 
 
III. MUSCULAR SYSTEM.
 
 
 
, § 1286. The muscular system also furnishes several strong argu
 
ments :
 
 
 
1st. The greater power of the muscles of the lower extremities.
 
 
 
2d. The extreme force and the arrangement of some of them, viz.
 
 
 
a. The thickness of the peronei muscles in the leg, the lower head
 
of which always draws the leg backward arid extends it, whiie the
 
upper two prevent the body from falling forward.
 
 
 
b. The arrangement of the flexors of the leg compared with that of
 
the flexors of the fore-arm ; for one of the three long flexors of the first
 
of these limbs is manifestly developed only in part ; so that the number
 
of the corresponding muscles in the fore-arm is much greater than in
 
the leg.
 
 
 
c. The thickness of the glutæi muscles, particularly the glutæus
 
maximus.
 
 
 
d. The multiplication of the muscles of the fore-arm to execute the
 
peculiar motions of the bones of the fore-arm : so likewise the difference between the number and development of the special muscles of
 
the thumb and little finger and those of the large and small toes.
 
 
 
e. The deeper situation of several of the muscles' of the fore-arm in
 
the upper extremity, and the foot only in the lower : such are particularly the flexor brevis and the extensor communis brevis.
 
 
 
f. The slight extent of the insertion of the flexors of the leg, which
 
favors the extension of this limb and prevents the continued forced
 
flexion it experiences in quadrupeds.
 
 
 
g. The smallness of the small muscles of the head, which, in connection with the looseness of the cervical ligament and the anterior
 
position of the occipital foramen, forms a very striking character, especially when we regard the great development of these parts in quadruped the head of which is however smaller than that of man.
 
 
 
§ 1287. All these circumstances united prove sufficiently that the
 
erect posture on the lower limbs is natural to man.
 
 
 
We must next examine how the erect posture is preserved in a
 
state of repose, and how the body when erect exercises the motion of
 
progression, or of standing and of â– walking, treating of the modifications
 
of each.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
179
 
 
 
 
 
B. OF STANDING.
 
 
 
§ 1288. The trunk and the lower limbs act in standing. The part
 
taken by the trunk consists,
 
 
 
1st. In the support of the head by the vertebral column.
 
 
 
2d. In the action of the very strong long muscles of the back which
 
fill the channels between the vertebrae and the ribs. They prevent
 
the body from falling forward, to which it is in some measure disposed
 
from the portion of the pectoral and abdominal viscera before the vertebral column. In fact, they are much more developed in their lower
 
part than at their summit. In this part also we feel fatigue and pain
 
most sensibly after standing a long time and especially after leaning
 
forward.
 
 
 
Tire trunk is supported by the lower extremities. Whenever the
 
position changes the pelvis presents a broad point of support for its
 
weight, and that of the head which is sustained by the vertebral
 
column. The articulation of the ossa femoris with the iliac bones in
 
front of their union with the spine increases the extent of this base of
 
support.
 
 
 
In standing, the weight of the body passes from this base to the
 
thigh, next to the leg, and finally to the foot, so that the body rests
 
upon the latter.
 
 
 
In the usual p ition on the two feet, besides the peculiarities relative
 
to the lower ex. . amities and which we have mentioned above, their
 
separation caused by the breadth of the pelvis and the length of the
 
neck of the thigh bones is very advantageous, as it increases the
 
extent of the base of support which falls between the soles of the feet ;
 
thus the attitude becomes unsteady and less firm when the breadth is
 
diminished by approximating the feet.
 
 
 
Standing, inasmuch as it depends on the lower limbs, results’ from
 
the action of all the muscles which arise from the trunk, and from the
 
different sections of these members. These muscles contract from
 
above downward, and thus move the divisions immediately above
 
them, and act in a direction the inverse of that which results in progression, since they approximate the least movable point to that which
 
is most movable. Thus the most active are, 1st, the gliitæi, which draw
 
the trunk backward ; 2d, the three flexors of the leg, which prevent the
 
pelvis from inclining forward ; 3d, the extensors of the thigh, excepting the rectus, which prevent the limb from falling backward ; 4th, the
 
lower head of the triceps, suree, which keeps the leg on the foot in a
 
direction intermediate between flexion and extension.
 
 
 
The other muscles, which confine the action of those we have mentioned, have little or no action, and this action is counteracted by that
 
of the others.
 
 
 
Standing on one foot, where the whole weight of the body rests on one
 
of the lower extremities, is practicable, especially by the length of the
 
 
 
 
 
180
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
neck of the femur and the breadth of the sole of the foot. This posture of
 
the body is preserved by the action of the muscles on the outside of
 
the lower limbs, by the broad abdominal muscles, and by the quadratus
 
lumborum, which act from below upward, preventing the body from
 
falling to the opposite side, where it is unsupported.
 
 
 
In standing on the toes there is no change except in the relations of
 
the bones of the leg and the action of its muscles. The toes are extended as much as possible on the metatarsal bones and the foot on
 
the leg, and the weight of the body then rests wholly on the toes and
 
also on the sesamoid bones of the foot, which are numerous and
 
large. This position is caused principally by the simultaneous action of the muscles situated on the anterior and posterior faces of the
 
leg and foot ; the tibialis anticus, the peronei, especially the peroneus
 
brevis, the extensors of the toes anteriorly, and the triceps suræ
 
posteriorly, are the principal agents.
 
 
 
At the same time the toes are forcibly pressed against the ground
 
by the action of their flexors, hence they are - more firmly fixed and
 
afford a more solid point of attachment to their muscles.
 
 
 
C. OF WALKING.
 
 
 
§ 1289. Walking is produced by the displacement of the lower
 
extremities, which move alternately either forward, backward, or
 
laterally, so that a distance exists between them, and consequently
 
the rest of the body is supported by only one of them. Each motion,
 
by which a limb is raised from the ground, separated from the other,
 
and is replaced on the ground, is a step.
 
 
 
This motion, in whatever direction it is performed, depends principally on the displacement of the femoral articulation, which is flexed
 
in walking forward or sideways, and, on the contrary, extended in
 
walking backward.
 
 
 
When we walk forward or backward the knee-joint is generally
 
slightly bent, which serves to raise the foot still more. The metatarsophalangean joint is most generally forcibly extended, articular when
 
the lower limb which is to be moved is behind the other; In walking,
 
the flexion of the haunch carries one of the two limbs more or less
 
before the other ; when left to itself, and the coxo-femoral articulation
 
is not bent, the foot falls again to the ground and the step is finished.
 
If we take long steps the pelvis also turns more or less around the
 
limb which remains fixed as around an axis ; hence the limb which
 
moves, and the corresponding side of the body, are carried farther forward. This effect is caused partly by the flexion of the other sections
 
of this limb and partly by the extension of the metatarso-phalangean
 
articulation.
 
 
 
It is merely necessary to mention these motions to know the muscles
 
which perform them.
 
 
 
 
 
MYOLOGY.
 
 
 
 
 
181
 
 
 
 
 
Running is a quick walk, most generally withlarge steps, which
 
differs from the ordinary walk not only by its rapidity, but also because
 
all the lower face of the foot rests on the ground.
 
 
 
Jumping is a sudden movement by which the body rises into the
 
air. In order to perform it all the joints of the lower limbs are flexed
 
and then suddenly extended ; from the shock which the body experiences from the soil against which it strikes it is carried upward
 
until its weight exceeds the motion communicated to it, and causes it
 
to return to the earth.
 
 
 
The leap in a straight line is always shorter than the oblique leap
 
because the weight of the body presents more resistance in the first
 
case than in the second.
 
 
 
In kneeling the articulation of the foot is flexed by the anterior
 
muscles of the leg, which act from above downward, and the articulation of the knee is changed in the same manner by the action of the
 
upper heads of the triceps suræ muscle.
 
 
 
In stooping the gastrocnemii muscles of the leg exercise all their
 
power ; at the same time the coxo-femoral articulation is flexed more
 
or less forcibly in order to lean the body forward, and to prevent its
 
centre of gravity from falling behind its base of support, and in this
 
manner to prevent its fall.
 
 
 
§ 1290. The motions of the trunk{ 1) are very limited. This is
 
proved by the vertebrae and also by the pieces of the sternum, which
 
are firmly united. Thus the motions of the trunk in every direction
 
depend but slightly on the displacement of the bones which form it, but
 
almost entirely on the lower limbs, and those in the coxo-femoral articulation, are performed by the muscles which extend from the thigh and leg
 
to the vertebral column and to the iliac bones. The mobility of the
 
ribs is much greater ; the changes in their situation produce the continual alternate changes which take place in the capacity of the chest,
 
and which result in inspiration and expiration. The examination of
 
these changes and of those which occur in the capacity of the abdominal cavity will be more in place after describing the pectoral and
 
abdominal viscera than here.
 
 
 
§ 1291. The head moves on the vertebral column ; it bends forward,
 
is extended backward, inclines to the side, and turns on its axis.
 
 
 
The last two motions take place almost entirely between the second
 
and first vertebræ, the last of which only accompanies the head. The
 
other two occur between the head and the atlas, and not between the
 
atlas and axis, because the odontoid process and the transverse portion
 
of the crucial ligament almost entirely prevent every displacement in
 
this direction between the first and second vertebræ.
 
 
 
Luxation cannot take place in flexion and extension on account of
 
the firmness of the attachments ; but it easily supervenes in the rota
 
(1) Winslow, Sur les mouvemens de la tête, du cou et du reste de l’épine du dos , in the
 
Mém. de Paris, 1730, p. 492-503.
 
 
 
 
 
182
 
 
 
 
 
DESCRIPTIVE ANATCMY.
 
 
 
 
 
tion of the first vertebra and of the head on the axis, when this motion
 
is performed quickly.
 
 
 
The cervical portion of the vertebral column must always be fixed
 
in order that these different motions ma_y be executed.
 
 
 
§ 1292. The b upper limbs are much more movable than the lower
 
both in regard to the trunk and their different sections, which doubtless
 
depends on the arrangement of these bones and the ligaments. The
 
motion of rotation on the axis particularly is much easier in the first
 
than in the second. The greater mobility of the upper limbs, considered as a whole, is also increased by the difference remarked in the
 
mode of articulation, of the first section of the bones of the two extremities, for the iliac bones are almost motionless on each other and on
 
the vertebral column, while the clavicle and scapula on the contrary
 
are very movable both on each other, and on the trunk.
 
 
 
Hence the motions of the upper limbs are not performed solely in
 
the scapulo humeral joint as those of the lower extremities are in the
 
coxo-femoral articulation, but take place at the same time in the scapulo- and sterno-clavicular articulations ; hence they are not only more
 
free, but also keep the bones together in the different motions they
 
perform. Hence the bones are much less firm, but they require less
 
strength, since the upper extremities are rarely obliged to sustain such
 
heavy loads as happens for instance in creeping, walking, or standing
 
on the hands.
 
 
 
If we except the fingers and toes, mobility diminishes from the periphery of the limbs to their centres.
 
 
 
A great difference between the partial motions of the two limbs
 
consists in the power of turning the radius on its axis and around the
 
ulna while the leg cannot move around the thigh, except as a whole,
 
the fibula being immovable on the tibia. The leg is capable only of
 
flexion and extension, while the fore-arm can execute also the motions
 
of pronation and of supination.Q I.)
 
 
 
Although in the two latter motions the radius is the principal part
 
displaced, the ulna is not however motionless ; for it is slightly extended in pronation and a little flexed in supination.
 
 
 
(1) Winslow, Obs. anat. svr la rotation , la pronatiop, la supination et d'antres
 
moiivcmens en rond, in the Mérn. de Paris, ÎV27, p. 25-33, — Vicq ci’Azyr, Œuvres,
 
vol. V. p. 343-351.
 
 
 
 
 
ANGEIOLOGY.
 
 
 
 
 
183
 
 
 
 
 
BOOK IV.
 
 
 
 
 
ANGEIOLOGY.
 
 
 
§ 1293. The vascular system(l) is composed of a central part, the
 
heart , whence all the blood departs and where all this fluid returns ;
 
of vessels which carry it away, the arteries ; and of vessels which
 
 
 
(1) We have already mentioned (vol, i. p. 280) the most important works on the
 
general conditions of the structure and external form of the vascular system in the
 
normal and abnormal state. We shall now mention the principal descriptive treatises.
 
They are,
 
 
 
I. Foe the whole system. — J. C. A. Mayer, Anatomische Beschreibung der
 
Blutgefässe des menschlichen Körpers , Berlin, 1777, 1778. — F. A. Walter, Angiologisckes Handbuch, Berlin, 1789.
 
 
 
II. Foe the heart, — 1st. Complete description of this organ in all its parts, both
 
in the normal and the abnormal state ; Senac, Traité de la structure du cœur, de son
 
action et de ses maladies, Paris, 1747, 1778. — 2d. Complete description of it in the
 
normal state ; R. Lower, Tractatus de corde, item de motu calore et transfusione
 
sanguinis, London, 1669. — J. N. Pechlin, De fabrica et usu cordis, Kiel, 1676. — Winslow, Sur les fibres du cœur et sur ses valvules, avec la manière de le préparer pour le
 
démontrer, in the Mémoires de Paris, 1711, p. 196, 201.— Vieussens, Traité de la
 
structure et des causes du mouvement natural du cœur, Toulouse, 1711. — Santorini,
 
Obs. anat ., Venice, 1724, ch. viii., Deiis quee in thoracemsunt . — Lieutaud, Obs. anat.
 
sur le cœur, in the Mém. de Paris, 1752, 1754. — 3d. Development of the heart;
 
Meckel, Sur l'histoire du développment du cœur et des poumons dans les mammifères,
 
in the journal complém. du Diet, des sc. médic., vol. i. p. 259. — Rolando, Sur la formation du cœur et des vaisseaux artériels , veineux et capillaires, same journal, vol. xv.
 
p. 323, vol. 16. p. 34. — Prévost et Dumas, Développment du cœur et formation du sang,
 
in the Annales des sciences naturelles, vol. iii. p. 46. — 4th. Structure of the heart in
 
respect to. the arrangement of its fibres ; C. F. Wolff, Dissertationes de ordine fibrarum muscularium cordis, in the Act. Acad. Petropol., 1780-1781, in the Nova act., vol.
 
L-viii. — J. F. Vaust, Recherches sur la structure et les mouvemens du cœur, Liege,
 
1821. — S. N. Gerdy, Mémoire sur l'organisation du cœur, in the Journ. compl. du
 
Diet, des sc. méd., vol. x. p. 97. — 5th. Pathological state ; A Burns, Observations on
 
some of the most frequent and important diseases of the heart, London, 1809. — Pelletan, Mémoires sur quelques maladies et vices de conformation du cœur, in the Clinique
 
chirurgicale, Paris, 1810, vol. iii. — Testa, Delle malattie del cuore, loro cagioni, specie,
 
cura, Bologna, 1810, 1813.' — Corvisart, Essai sur les maladies et les lésions organiques
 
du cœur et des gros vaisseaux, Paris, 1818. — Kreysig, Ucber die Herzkrankheiten,
 
Berlin, 1814, 1817. — Laennec, De l'auscultation médiate , or Traité du diagnostic des
 
maladies des poumons et du cœur, Paris, 1819, p. 195-445. — Bertin, Traité des
 
maladies du cœur et des gros vaisscu. v, Paris, 1824.
 
 
 
III. For the arteries. — H aller, Icônes anatomicœ, Gottingen, 1745, 1756. — A.
 
Murray, Descriptio arteriarum corp. humani tabulis redacta, Upsal, 1783, 1798. — J.
 
F. S. Posewitz, Physiologie der Pulsadern des menschlichen Körpers, Leipsic, 1795.
 
— J. Barclay, A description of the arteries of the human body, Edinburgh, 1818, 8vo.
 
— Tiedmann, Tabulae arteriarum corporis humani, Carlsruhe, 1822, 1824. — Hodgson,
 
Diseases of the arteries and veins.
 
 
 
IV. For the veins. — B esides the tables of Loder see Breschet, Sur le système
 
veineux, now publishing.
 
 
 
V. For the Lymphatics. — T he works mentioned in the first volume contain also
 
a description of this system.
 
 
 
 
 
184
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
return it, the veins and the lymphatics. The last mentioned carry a
 
fluid different from the blood, they are the annexes or appendages of
 
the venous system.
 
 
 
SECTION I.
 
 
 
OF THE HEART.
 
 
 
CHAPTER I.
 
 
 
GENERAL REMARKS.
 
 
 
§ 1294. The heart (cor) is a hollow muscle irregularly conical or
 
pyramidal, situated in the centre of the chest, between the two lungs,
 
and inclosed in a special envelop called the pericardium. Its vessels
 
are numerous, but it has few nerves : it is formed of several cavities,
 
some of which are separated, while others communicate together. Its
 
tissue is formed of fibres united in superimposed layers, and is connected
 
on one side with the large venous trunks of the lungs and body, and
 
on the other with the large arterial trunks of both. Each of these
 
characters deserves to be specially considered.
 
 
 
I. FORM.
 
 
 
§ 1295. The shape of the heart is that of a cone or an irregular
 
pyramid. We distinguish in it a broad and thick base (basis) and a
 
summit (apex), which is generally blunt and bifurcated, an upper and
 
anterior face which is concave, and an inferior and posterior which is
 
smaller and flatter ; two edges, a posterior which is thick and pointed,
 
the anterior is smaller, shorter, thin, and sharp.
 
 
 
The base of the heart is formed, properly speaking, by that part of
 
the organ directly connected with the veins : we may then term it the
 
venous portion of the heart (pars cordis venosa). However we generally apply the term base of the heart to the upper region of the arterial
 
portion. The venous portion is formed of two auricles. It is separated
 
from the next by a large groove, called the groove of the base , the auricuto-ventricular groove , or circular groove ( sulcus baseos , s. alrio-ventricularis, s. circularis). Its form is an oblong square and its breadth
 
exceeds its height.
 
 
 
The succeding portion, which is situated before the auriculo-ventricular groove, is directly connected with the large arterial trunks. We
 
may then term it the arterial portion of the heart (pars arteriosa cordis).
 
It is formed by the two ventricles. It terminates in a blunt summit,
 
which is usually more or less evidently grooved. This groove is sometimes very large.
 
 
 
 
 
ANGEIOLOGY.
 
 
 
 
 
185
 
 
 
 
 
The longitudinal groove (sulcus cordis longitudinales superior et inferior) exists on both faces of the heart, from its base to its summit, and
 
consequently in all its length.
 
 
 
The principal branches of the nutricious vessels of the organ are
 
situated in these grooves : they communicate on the side of the base by
 
a groove, which descends perpendicularly between the two auricles,
 
and on the summit by the depression observed in this place. They
 
mark the course of the septum within the heart (septum cordis).
 
 
 
§ 1396. The septum passes also across the venous portion of the
 
heart or the auricles as well as its arterial portion or the ventricles. It
 
separates completely these two synonymous parts, and consequently
 
divides the heart into a right or an anterior and a posterior or left half.
 
That part which passes between the auricles is called the septum atriorum, and that between the ventricles is called the septum ventricidorum.
 
The right part of the heart is called the pulmonary heart (cor pulmonale),
 
because the pulmonary artery arises from it, or the heart of the black
 
blood, from the color of this fluid within it. The left is termed the
 
aortal heart (cor aorticum ), because the aorta arises from it, or the heart
 
of red blood, from the color of the blood within it. We employ sometimes
 
also the terms of first ventricle, to designate the anterior, and second
 
ventricle, to mark the posterior ; but these are less convenient.
 
 
 
II. WEIGHT AND SIZE.
 
 
 
§ 1297. The weight of the heart in a fully grown man is about ten
 
ounces ; whence it is to that of the whole body as 1 is to 200.
 
 
 
Its length, measured from the centre of the auricles, is between five
 
and six inches its mean length is five and a half inches, four of which
 
are for the ventricles and one and a half for the auricles. The breadth
 
of the ventricles united is generally three inches at their base and that
 
of the auricles is three and a half inches. (1 )
 
 
 
III. SITUATION.
 
 
 
§ 1298. The heart is placed obliquely from right to left, from behind
 
forward, and from above downward ; so that its base is nearly opposite
 
 
 
(1) A knowledge of the perfectly normal proportions of the heart in the healthy state
 
is very important to the physician, since without it he can establish no certain diagnosis of the diseases of the central organ of the circulation. We cannot do better
 
than to quote the following passage of Laennec on this subject : “ The heart, in
 
cluding the auricles, should be equal to, a little less, or a little larger than the first
 
of the subject. The walls of the left ventricle should be a little more than twice as
 
thick as the walls of the right ventricle ; they should not collapse on cutting into the
 
ventricle. The right ventricle, a little larger than the left, presenting- smaller fleshy
 
pillars, although its parietes are thinner, ought to collapse after the incision.” (De
 
V auscultation médiate, vol. ii. p. 270.) “Reason teaches and observation proves, that
 
in a well formed subject the ca\ ities of the heart are nearly equal ; butas the parietes of
 
the auricles are very thin and those of the ventricles are much thicker, it follows that
 
the auricles form only one third of the whole volume of the organ or the half of that
 
of the ventricles.” ( lb .) ~ F. T.
 
 
 
VOL. II.
 
 
 
 
 
24
 
 
 
 
 
1S6
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
the eighth dorsal vertebra, from which it is separated by the esophagus and aorta, and its summit corresponds to the cartilage of the sixth
 
rib, or to the interval, which separates it from the next. Its lower face,
 
which is flattened, corresponds to the upper face of the central tendon
 
of the diaphragm, and the upper to the central and left portion of the
 
anterior wall of the chest.
 
 
 
IV. TEXTURE.
 
 
 
§ 1299. The heart is formed of several layers of muscular fibres,
 
situated between two thin, smooth, and polished membranes, the inner
 
and outer membranes of the heart. The latter is the inner layer of the
 
pericardium.
 
 
 
The outer surface of the heart is smooth and uniform in relation to
 
the inner, even when we have removed the outer membrane.
 
 
 
The inner surface is very uneven and reticulated, which arises from
 
its being formed of numerous rounded, flat, and distinct muscles, which
 
intercross continually and which are called fleshy •pillars ( trabeculœ
 
carneœ). The mnscular substance of the heart is generally harder,
 
more solid, and more elastic than that of other muscles.
 
 
 
As the arrangement of these fibres(l) differs wholly in the venous
 
portion from what it is in the arterial portion, as it is not exactly the
 
same in the right and left portions, and as it finally differs according
 
to the subject, all that can be said generally may be reduced to the
 
following corollaries :(2)
 
 
 
1st. The directions of the layers are more or less opposite. But in
 
the recent state, far from being entirely separated from each other, they
 
intercross differently ; so that all those of one portion of the heart constantly contract uniformly and diminish the cavity they circumscribe in
 
every direction.
 
 
 
The union of the different layers takes place partly by more or less
 
manifest muscular fibres.
 
 
 
2d. The fibres which form the layers are united in fasciculi of various sizes, which vary more or less in their origin and their direction,
 
and which are often separated by greater or less spaces. These fasciculi are sometimes rounded and sometimes flattened, — a difference
 
which seems to depend on determinate laws, since it is constant in the
 
different regions of the heart. For instance the right and left ventricles
 
 
 
(1) Wolff, De online fibrarum muscularium cordis, diss. vii. De stratis fibrarum
 
in Universum. In nov. act. petrop., vol. iii., 1785, p. 227-249. — Gerdy, loc. cit., p. 101. —
 
Vaust, loc. cit., p. 102, etc.
 
 
 
(2) Gerdy has established a law, that all the fibres, whatever is their extent, situa
 
tion, and direction, form webs, which are convex toward the point of the heart, and
 
which are nearly superficial at one extremity and deep at the other ; so that for
 
instance the external or internal fibres are the same reversed, and having passed
 
through the thickness of the ventricle. The extremities of these muscular webs are
 
constantly inserted in the base of the heart, around the different auricular'and arterial orifices of the ventricles, either directly or by tendons attached to the auriculoventricular valves (loc. cit., p. 101). F. T.
 
 
 
 
 
ANGEIOLOGY.
 
 
 
 
 
1S7
 
 
 
 
 
are not similar in this respect nor in regard to the arrangement of their
 
fibres, and the same is true of other parts also. Thus the inner layers
 
are generally rounded and form fleshy pillars. The auricular appendages of the auricles are formed of rounded fasciculi, and the auricles of
 
flattened fasciculi.
 
 
 
From this arrangement we may deduce that the firmest parts are
 
formed of rounded fasciculi. But the fibres and the fasciculi formed by
 
them are united by intermediate fibres, which may be distinguished
 
with facility.
 
 
 
The fibres and fasciculi are every wdrere interlaced with each other,
 
conformably withall the in voluntary muscles. They are united principally in two ways : sometimes the ends of the fibres and fasciculi join, and
 
sometimes they are united by intermediate filaments, which arise from
 
their lateral portions.
 
 
 
In the first case, either the fasciculi go to meet each other and the
 
extremities of those which continue together intermix like the teeth of
 
a saw, as is the case with the digitations of several adjacent muscles,
 
or some fibres are attached obliquely to others at acute angles, as the
 
fibres of the penniform muscles are implanted in their tendons, and
 
finally, as is the case most generally, the fibres or fasciculi which go
 
side by side unite at very acute angles.
 
 
 
The lateral union takes place principally between the insulated fibres
 
and the small fasciculi of fibres, especially in the outer layer. Sometimes it is irregular ; so that those fibres which are evidently separated
 
in the rest of their course are placed one against another in a part of
 
this same course, whence the reticulated structure is more or less evident. It is sometimes regular, and we see oblique fibres going from
 
each side, which unite. The redness and determinate form of the intermediate filaments always demonstrate that they are not formed of cellular tissue but of real muscular substance.
 
 
 
The mode in which the filaments are united also presents determinate differences in the different regions of the heart.
 
 
 
3d. In the ventricles, the external layers go obliquely downward,
 
backward, and from right to left. The direction of the central is opposite, and the most internal, which form the fleshy pillars, extend longitudinally from the summit to the base.
 
 
 
On the contrary, the transverse direction predominates in the auricles.
 
The external layer, which is the strongest, proceeds in this direction,
 
while the internal, which forms only insulated fasciculi, has a longitudinal direction.
 
 
 
4th. All the external layers are not equally extended. Generally
 
the external layers are those only which cover all the surface of the
 
ventricles ; the central are smaller and occupy only a third of the
 
heart. If we except the most internal, that which forms the fleshy
 
pillars, they diminish in direct ratio to their depth. They disappear
 
first at the summit of the organ, and in reascending from this point to
 
the base of the ventricles, they are deeper and deeper ; so that the deepest
 
 
 
 
 
ISS
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
arc found only at the base. Hence this part of the heart is the
 
thickest.
 
 
 
We observe also occasional spaces between the layers, which extend the whole length or all the breadth of the ventricles.
 
 
 
5th. The outer layers differ from the central ones, inasmuch as they
 
are stronger and their fibres are more intimately united together.
 
 
 
Thus the fibres and the fasciculi of the inner layers are more easily
 
demonstrated. But the external forcibly embrace and compress these
 
latter ; so that they contribute essentially to the firmness of the
 
heart.
 
 
 
6th. The fibres of the two portions of the heart are not continuous, at
 
least not all of them, with each other, so that the same layers are
 
reflected on the two ; but the fibres of the two ventricles terminate in
 
the septum. The upper and lower faces of the heart are not arranged in
 
precisely the same manner : the separation is seen with more difficulty
 
in the first than in the second. We remark also three different arrangements in the upper face. In fact, either we cannot distinguish the
 
least trace of separation and the fibres are uninteruptedly continuous
 
with each other, or two fibres are in fact applied one on the other, but
 
a species of suture serves as a line of demarkation between them, or
 
finally they mingle with each other by digitations.
 
 
 
Wolff states that on the lower face, the fibres of the two ventricles
 
are separated by a distinct and very broad band, formed of longitudinal
 
fibres, and which diminishes insensibly from the base to the summit, to
 
which these fibres are attached on the two sides. But we have usually
 
found but a slight, and often no trace of this arrangement.
 
 
 
7th. The upper extremities of the fibres of the heart are attached to
 
a fibro-cartilaginous tissue,(l) formed
 
 
 
a. Of two oblong, rounded projections or tubercles, usually three or
 
four lines long, little less than a line thick, seen on both sides of the orifice of the aorta.
 
 
 
b. Of a thin band, which surrounds the posterior part of the circumference of the aorta and unites the two tubercles.
 
 
 
c. Of four filaments, placed in the circular groove on the base of the
 
heart, two on the right and two on the left, an anterior and posterior
 
on each side. Below these four filaments the two anterior arise from
 
the tubercles. The right anterior goes into the anterior and upper part
 
of the circular groove ; the left into the upper and posterior part. The
 
posterior two arise by a very short common trunk, which is only a few
 
lines long, from the band which unites the two tubercles, near that
 
of the right side, and proceed in an opposite direction to the lower part
 
of the circumference of the circular groove.
 
 
 
These anterior and posterior filaments are situated at the venous
 
orifices of the ventricles. They do not surround the base of the heart
 
 
 
(1) C. D. F. Wolff, Dc or dine fibr arum muscularium cordis , Diss. ii., de textu cartilagine ocordis , sivc dcfilis cartilagineo-osseis corumque in basi cordis distribution. In
 
Act. Petropol., 1781, vol. i. p. 211. — Gerdy, loc. cit., du tissu albugine cardiaque , p. 97.
 
 
 
 
 
A NGEIOLOGY,
 
 
 
 
 
189
 
 
 
 
 
and form a complete ring, but terminate near the edges of each orifice
 
and gradually lose themselves in the cellular tis'sue.
 
 
 
This cartilaginous tissue is surrounded entirely by a thin, firm, but
 
loose sheath, a real perichondrium. It is covered more externally by
 
the outer membrane of the heart and internally by its inner membrane.
 
 
 
The external muscular or superficial fibres arise principally from the
 
cartilaginous tubercles and filaments, and from the cellular tissue between the extremities of the latter ; so that the fibres, which come from
 
the tubercles and from the origin of the filaments, adhere to them very
 
intimately, while the others are united only by a cellular sheath which
 
surrounds them.
 
 
 
 
 
v. vessels. (1)
 
 
 
§ 1300. The blood-vessels of the heart are proportionally very large
 
and are called the coronary vessels ( vasa coronaria cordis). The coronary arteries and veins resemble each other in many respects :
 
 
 
1st. These vessels (the arteries) arise directly from the beginning
 
of the trunks of the vessels of the body, or they (the veins) open directly
 
into the heart.
 
 
 
2d. They turn around the base of the heart in the circular groove,
 
whence they send toward the summit large branches which arise at
 
almost right angles : these go to the ventricles and proceed along the
 
heart, while the others are smaller and follow an opposite direction,
 
proceeding to the auricles.
 
 
 
3d. The large trunks and the large branches extend on the outer
 
face of the organ and ramify internally.
 
 
 
4th. The veins have valves at the places where they open but not
 
in their course. There are two arteries of nearly equal calibers, while
 
we find only a single large coronary vein, which is constant ; but beside this last we observe several, which are smaller, which open 'directly
 
into the heart, but not constantly, except into the right part of the
 
organ, and particularly into the right auricle : they do not open, even,
 
except into the septum, and they do not empty their blood into the left
 
part of the heart, (2) as some anatomists have pretended, and among
 
others Vieussens(3) and Thebesius.(4) In fact, Abernethy has very
 
recently supported this latter opinion, viz. that the venous blood of the
 
heart mixes with the arterial blood which nourishes the body, without
 
passing through the lungs ; he has only modified it by saying, that
 
these orifices of the coronary veins in the left portion of the organ serve
 
principally to prevent repletion of the right portion in those cases where
 
the passage of the blood through the lungs is obstructed ; because,
 
 
 
(1) Haller, De vasis cordis propriis, Gottingen. 1737. — Iterates observationes, 1739.
 
— Geisler, Commentatio de sanguinis per vasa coronaria cordimotu, Leipsic, 1743.
 
 
 
(2) Sabatier, Sur les veines de Thebesius ; in the Traité d’anat., vol. iii.
 
 
 
(3) Nouvelles découvertes sur le cœur, Montpelier, 1706. — Traité du cœur, 1715.
 
 
 
(4) De circula sanguinis in corde, Leipsic, 1708. — De circulo sanguinis per cor ,
 
Leipsic, 1759.
 
 
 
 
 
190
 
 
 
 
 
DESCRIPTIVE ANATOMY,
 
 
 
 
 
having injected the cardiac arteries and veins in a subject whose lungs
 
were diseased, he has seen the fluid penetrate into the left ventricle by
 
broad openings. But as generally injections, even when very fine,
 
transude on all the inner face, although no venous orifices are perceptible on the left side, we have reason to admit that the openings existing in the cases observed by Abernethy were produced accidentally,
 
either during life or after death, by obstacles to the course of the injection, on account of the feeble resistance of the tunics of the veins weakened by disease, and considerably distended, both by the blood accumulated in these vessels and by the injected mass.
 
 
 
VI. NERVES.
 
 
 
§ 1301. The nerves(l) of the heart are proportionally smaller than
 
those of the voluntary muscles. They arise from the upper and lower
 
cervical ganglions of the great sympathetic nerve, from the cervical
 
portion of the nerve between these two ganglions, or from the central
 
ganglion sometimes found in this place. Some arise directly from the
 
nerve, others from the plexuses formed by the filaments which come
 
from the ganglions and by others sent off by the pneumo- gastric nerve.
 
 
 
The relations of the nerves of the heart with its muscular substance
 
have been the subjects of dispute. Some anatomists, Behrends(2)
 
among others, deny that this substance, and consequently that the heart,
 
possesses nerves, which they pretend are distributed only to the cardiac
 
vessels. Others on the contrary, as Scarpa, Munniks,(3) and Zeirenner,(4) maintain that they really go to the heart as well as to all other
 
muscles.
 
 
 
The partisans of the first hypothesis adduce the following arguments :
 
 
 
1st. Anatomical examination, whence it results that the cardiac
 
nerves, which we cannot follow except to the third ramification of the
 
coronary arteries, do not enter the substance of the heart but go only
 
to the arteries. (5)
 
 
 
2d. The origin of the cardiac nerves ; they arise from the great
 
sympathetic nerve, the ramifications of which go only to the arteries. (6)
 
 
 
 
 
(1) J. F.. Neubauer, Descriptif) nervorum cardiacorum, Frankfort and Leipsic,
 
1772. He has figured the nerves of the right side. — E. P. Andersch, De nervis ; in the
 
Nov. comm. Gœtt ., vol. ii., and Königsberg, 1797. He has represented those of the left
 
side. These figures have been copied in Haase, Cerebri nervorumque corporis humant
 
repetita, Leipsic, 1781. — A. Scarpa, Tabulœ neurologicæ ad illuslrandum historiam
 
anatomicam cardiacorum nervorum cerebri , glossopharyngœi et pharyngæi ex octavo
 
cerebri, Pavia, 1794.
 
 
 
(2) J. Behrends, Diss. qua demonstratur cor nervis carere, additâ disquisitione de
 
vi nervorum arteriös cingentium, Mayence, 1792.— A. T. N. Zerrenner, An cor nervis
 
careat iisque carere possit? Erford, 1794.
 
 
 
(3) Observationes varice. Diss. auat. med., Groningue, 1805, 1-17.
 
 
 
(4) Zerrenner, An cor nervis careat iisque carere possit ? Erford, 1794.
 
 
 
(5) Behrends, loc. cit , p. 5, 8.
 
 
 
(6) Id., ibid., p. 8.
 
 
 
 
 
ANGEIOLOGY.
 
 
 
 
 
191
 
 
 
 
 
3d. The smallness of those nerves which is in direct ratio with the
 
thinness of the fibrous coat of the arteries,(l) and which contrasts on
 
the contrary with this law, that the number and size of the nerves
 
correspond to the power and frequency of the motions of the muscles.^)
 
 
 
4 th. The insensibility of the heart, the motions of which are independent of the nervous system, since it beats regularly although
 
removed from the body, (3) and the excitement of the nerves, whether
 
mechanically or dynamically, by means of galvanic electricity, do not
 
alter its motions, (4) and its pulsations are not deranged when the nervous system is paralyzed as in apoplexy. (5)
 
 
 
5th. The integrity of the motions of the heart, notwithstanding the
 
administration of opium. (6)
 
 
 
But all these arguments can be refuted with greater or less facili'y.
 
In fact :
 
 
 
1st. The manner in which the cardiac nerves are distributed and
 
their proportion both to the muscular substance and to the vessels,
 
do not differ essentially from what is seen in the same respects in
 
the voluntary muscles. (7) Here also the nerves and the ramifications
 
of the vessels are very compactly situated in regard to each other, and
 
we do not see the nerves unite to the muscular substance. Besides
 
the cardiac nerves are closely connected with the vessels only in their
 
largest branches, and not at all in many animals.
 
 
 
2d. The muscular substance of the heart is only a greater development of the fibrous membrane of the vascular system, so that the distribution of the branches of the great sympathetic nerve within it does
 
not present an aberration from the type of this nerve.
 
 
 
3d. The cardiac nerves possess more medullary substance than
 
those of the voluntary muscles. They arise from the ganglions of the
 
great sympathetic nerve, and through them from ail the _ spinal
 
marrow. Their action is probably favored by the mutual contact of
 
the blood and of the inner face of the heart ; very probably also the
 
size of the nerves which go to the voluntary muscles relates to their
 
functions which is to conduct the influence of the will.
 
 
 
4th. The facts cited in the fourth paragraph are explained partly by
 
the smallness and partly by the texture especially the softness and
 
gelatinous nature of the cardiac nerves, and from the circumstance
 
that they arise from the ganglions. Besides they are correct only to
 
a certain extent, since the motions of the heart are not entirely independent of the nervous system. The passions have a marked influence on the number and strength of its pulsations. Impressions of
 
 
 
(1) Behrcnds, loc. cit., p. 8, 9.
 
 
 
(2) Id., ibid., p. 10.
 
 
 
(3) Id., ibid., p. 11.
 
 
 
(4) Id., ibid., p. 20.
 
 
 
(5) Id., ibid., p. 12.
 
 
 
(6) Id., ibid., p. 11.
 
 
 
(7) Scarpa, loc. cit., § 13. — Munniks, loc. cit., p. 6.
 
 
 
 
 
192
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
every kind on the nervous system modify its motions more or less sensibly.(l)
 
 
 
In fact several observers, particularly Valli, Volta, Klein, (2) and
 
Bichat, have doubted the influence of electricity on the motions of the
 
heart; but the observations of Fowler, Schmuck, Pfaff,(3) Rossi, (4)
 
Giulio,(5) Humboldt, (6) Munniks,(7) and Nysten, and our own also,
 
prove it to be real.
 
 
 
The non-affection of the heart in paralysis of the brain proves nothing'
 
in regard to the relations between the nerves and this organ, since the
 
irritability of the voluntary muscles is not altered in apoplexy. This
 
apparent difference depends only on that between the excitants of
 
the voluntary and involuntary muscles. In fact the excitant of the
 
first is the influence of the brain, and that of the second the substance
 
contained in their cavity, which in the present case is the blood. The
 
motions of the heart continue also in cerebral paralysis, while those
 
of the other muscles are not performed ; the activity of these last seems
 
extinct while it is only no longer seen.
 
 
 
5th. The observations of Haller, of Fontana, of Whytt,(8) and of
 
Alexander, (9) prove that the heart, like the voluntary muscles, is sensible to the influence of opium, whether the narcotic acts directly upon it,
 
or is placed in contact with the nervous system or with any organ
 
whatever. These observations and experiments prove that the relation between the heart and the nerves is perfectly like that between
 
the nerves and muscles generally, and more, because the effect of opium
 
upon the heart is much more evident when this substance is placed
 
in relation with the nervous substance than when applied directly to
 
the heart.
 
 
 
 
 
VII. VENOUS PORTION.
 
 
 
§ 1302. The characters of the venous for lion of the heart, (10) the
 
auricles, are,
 
 
 
1st. The muscular substance of its parietes is so thin that the two
 
membranes of the heart touch in several places.
 
 
 
2d. Its form is irregularly quadrilateral.
 
 
 
(1) See on this subject Legallois, Experiences sur le principe de la vie, Paris, 1812,
 
. — Wilson Philip, in the Phil. Trans ., 1815, part i. p. 65-97 ; part ii. p. 224-246. — Ici.
 
An experimental inquiry into the laws of the vital functions, London, 1818.
 
 
 
(2) In Pfaflf, Vcber thicrischc Electricitât und Reizbarkeit, p. 119.
 
 
 
(3) In PfaflF, loc. cit., p. 140.
 
 
 
(4) Mém. de Turin , vol. vi.
 
 
 
(5) Voig’ht, Magazin , vol. v. p. 161.
 
 
 
(6) Ueber die gereizte Muskel-und Nervenfaser , vol. i. p. 340-349.
 
 
 
(7) Loc. cit., p. 115.
 
 
 
(8) In Pfaffj loc. cit., p. 140.
 
 
 
(9) Memoirs of the Manchester society, vol. i. p. 98.
 
 
 
(10) Ruysch, Epist. anat. problemala décima de auricularum. cordis earumque
 
fibrarum molricium structura, Amsterdam, 1725. — A. F. Walther, De structura cordis
 
auricularum, Leipsic.
 
 
 
 
 
ANGEIOLOGY.
 
 
 
 
 
193
 
 
 
 
 
3d. It is composed of a part into which the veins open directly the
 
cavity of the auricle , the sac (sinus), and another upper and anterior,
 
the auricular appendix (auricula), which projects above the sac.
 
 
 
The exact limits of these two parts cannot be pointed out, or rather
 
anatomists do not distinguish them according to the same principles on
 
the right and left sides. On the left side the appendix is readily distinguished from the sac, because it suddenly forms a very rounded projection, which is much narrower, and has thicker walls on the upper
 
anteiior and left angle. On the right side, on the contrary, this name
 
is applied to a part, the walls of which are very thick, which is
 
formed on the left by the confluence of the two venæ eavæ, terminates
 
above in a blunt summit, and which is not sensibly separated from
 
the rest, while, if we remained true to the analogy, this term should
 
be applied only to the small appendix which terminates the auricle
 
above, and which is elevated on the left along the vena cava superior.
 
 
 
4th. It is directly continuous with the venous trunks which open
 
into it.
 
 
 
VIII. ARTERIAL PORTION.
 
 
 
§ 1302. The characters of the arterial portion of the heart, the
 
'ventricles, are,
 
 
 
1st. Their parietes are thicker, so that the internal and the external
 
membranes are every where separated from each other by a muscular
 
substance. The thickness of the parietes of each portion of the heart
 
is then in direct ratio with the extent passed through by the blood
 
it sends forward.
 
 
 
2d. The arterial portion is considerably larger and broader than the
 
venous portion.
 
 
 
3d. Its external form is elongated, rounded, and pyramidal, and
 
determines, properly speaking, the form of the whole heart.
 
 
 
4 th. At its upper extremity are two openings, the venous and the
 
arterial, which establish the communication, the first between the ventricle and the auricle, and the second between the ventricle and the
 
artery w hich arises from it. The venous orifice is almost perpendicular ;
 
its direction is from before backward and from right to left ; the arterial
 
is almost horizontal and is situated a little above the former farther inward and nearer the septum.
 
 
 
Both are rounded j the venous is broader than the arterial. Its form
 
is elliptical, while the latter is nearly circular.
 
 
 
Neither the venous nor the arterial opening is perfectly loose ; both
 
have valves. The valves placed at the arterial opening are very
 
similar in their arrangement to those found in the common veins they
 
are however much larger and are usually three in number. Thenconvex and attached edge looks toward the heart while the loose edge,
 
which has two concavities and which is thicker than the rest of the
 
membrane, is turned toward the cavity of the artery. In the centre
 
 
 
Vol. II. 25
 
 
 
 
 
194
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
of the latter we observe a fibro-cartilaginous tubercle ( nod-ulus ). The
 
blood which comes from the ventricle pushes them toward the circumference of the artery and against its parietes. On the contrary the
 
blood which tends from its specific gravity to return from the artery
 
into the ventricle separates them from these same parietes, their loose
 
edges then touch, and they form a horizontal septum between the
 
cavity of the artery and the ventricle, which prevents the reflux of
 
the blood into the latter. The tubercles complete this septum and
 
close the space in the centre of the artery between the three valves.
 
 
 
The valves of the venous orifice differ from those of the arterial
 
opening, and from all other valves, since they are attached much more
 
firmly, hence they close more completely the opening around which
 
they are placed. A narrow cartilaginous ring, which is not however
 
perfect, exists on all the circumference of the venous opening ; this
 
sometimes ossifies in advanced age, especially in the left portion of the
 
heart, and is situated deeply between the muscular fibres of the ventricle and those of the auricle.
 
 
 
This is the cartilaginous tissue already described as the origin of
 
the external muscular fibres of the heart. The venous valve is
 
attached to this tissue by its posterior edge, but its opposite and uneven
 
edge, unlike that of all the other valves, is not loose ; many flat and
 
solid tendinous filaments, which extend from the base to the summit of
 
the heart, arise from the valve, on which they are often united or pass
 
over it and go to the opposite part of the circumference of the heart,
 
soon unite into larger cords, and are attached to the parietes of the
 
heart, and principally to its fleshy pillars. As the latter shorten when
 
the heart' contracts, the different parts of the valves then approach
 
each other and the opening is forcibly closed. It is necessary that
 
the loose edge of these valves should be thus attached since they must
 
resist not only the weight of the blood like the other valves, but also
 
the action of the muscular parietes of the heart, which forcibly push
 
forward the arterial blood.
 
 
 
5th. The arterial portion of the heart is divided into an upper and
 
lower half, which are separated by the upper part of the valve of the
 
venous orifice at the upper and posterior parts of the ventricles, and
 
which blend together at the summit of the heart, so that the ventricles,
 
although resembling externally an elongated cone, form in fact two
 
arched canals, convex forward, and the greatest convexity of which
 
corresponds to the summit, and are more extensive in this part than in
 
any other.
 
 
 
6th. The reticulated structure of the ventricles is much more distinct than that of the auricles. Some of the fleshy pillars form rounded,
 
elongated projections, terminating in blunt summits (musculi papillares ),
 
which go toward the base of the heart, and from the extremity of
 
which several tendinous filaments proceed to attach themselves to the
 
loose edges of the venous valves. Farther, those fleshy pillars which
 
are attached by their two extremities, as well as those which have
 
 
 
 
 
r
 
 
 
 
 
ANGEIOLOGY.
 
 
 
 
 
195
 
 
 
 
 
one end loose, communicate with each other at intervals by tendinous
 
fibres. The direction of the principal fasciculi is longitudinal, the
 
smaller which unite the preceding are oblique. Near the summit the
 
reticulated texture is more and more developed, and the parietes become thinner in the same proportion.
 
 
 
IX. RIGHT AND LEFT PORTIONS.
 
 
 
§ 1303. 1st. The right half of the heart is considerably thinner than the
 
left. This difference is very striking between the two ventricles, where
 
the relation is generally as one to four or to five. Even then we find,
 
as between the auricles and the ventricles generally, that the power
 
of the parietes is in direct ratio with the space passed through by the
 
blood winch comes from them. The greater thickness of the walls of
 
the left ventricle determines the form of the whole arterial portion of
 
the heart. The right wall formed only by the septum is convex, and
 
the left appears fitted to it like a sling.
 
 
 
2d. The substance of the right side, especially that of the ventricle,
 
is softer and looser than that of the left side.
 
 
 
3d. The right side is broader than the left after death.(l) This
 
difference also is most marked between the two ventricles, but it is not
 
yet determined if it exists constantly during life or supervenes only
 
after death.
 
 
 
Many anatomists, particularly Lower, (2) Santorini, (3) Weiss, (4)
 
Lieutaud,(5) and Sabatier, (6) have adopted the latter opinion, while
 
most others favor the first.
 
 
 
This hypothesis has been supported sometimes by the result of
 
measurement, and sometimes by the fact that the left ventricle is as
 
much longer as the right is broader, and sometimes by experiments
 
and observations, from which it has been concluded that the right
 
side appears broader after death, only because it is more distended by
 
the blood which remains stagnant in the lungs from their inaction,
 
while previously the passage of the blood from the left ventricle was
 
not obstructed ; whence the left ventricle seems to be narrower compared to the right, in proportion to the less quantity of pulmonary
 
blood received by it through the pulmonary veins. In men and animals who have died suddenly from the injury of the large vessels,
 
or of those which communicate with the right portion of the heart,
 
when consequently this cause of the distention of the right ven
 
(1) Helvétius, Sur l’inégalité de capacité qui se trouve entre les organes destinés
 
à la circulation du sang , dans le corps de l’homme, et sur les changemens qui arrivent au sang enpassant par le poumon, in the Mêm. de Paris, 1718, p. 222-281.
 
 
 
(2) Loc. cit., p. 34.
 
 
 
(3) Loc. cit., p. 144, 145.
 
 
 
(4) De dextro cordis ventriculo postmortem ampliore, Altdorf, 1745.
 
 
 
(5) Essais anat., p. 230, 231.
 
 
 
(6) Sur /’inégale capacité des cavités du coeur et des vassieaux pulmonaires, in the
 
Mém de Paris.
 
 
 
(7) Lieutaud has brought forward this argument.
 
 
 
 
 
196
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
tricle did not exist, the capacity of the two portions has been exactly
 
or nearly the same.(l) Finally, when the left ventricle is placed in
 
the same condition by means of a ligature as is the right ventricle at
 
the time of death; while on the contrary the blood is removed from
 
the latter by cutting the pulmonary artery, or the vena cava, we find
 
that the relation between the two ventricles is the inverse of that
 
which commonly exists, that is, that the right ventricle is narrower
 
than the left.(2)
 
 
 
The vein's appear much larger than the arteries after death, undoubtedly from the same cause.
 
 
 
To these experiments we may add that we sometimes find the right
 
ventricle narrower than the left from the effect of disease, such as ossification or some other malady of the valves of the aorta, in which case
 
the difference must be explained precisely in the same manner. We
 
have before us several preparations in which, beside a considerable
 
dilatation of the left ventricle arising from this cause, there is at the
 
same time a great contraction of the right ventricle, proving that the
 
results drawn from these facts cannot be opposed, by saying that the
 
dilatation of the right cavity of the heart in the usual state of things
 
should extend also to the left portion from the influence which it exercises on the veins and arteries of the body, and consequently that the
 
right half is really larger during life since the left is itself distended.
 
Since the cause of the greater distention of the right portion, that is,
 
the more difficult passage of blood through the lungs, supervenes only
 
at the moment of death, the opinion that the right ventricle is also more
 
capacious during life cannot be sustained. (3)
 
 
 
That the cause above mentioned is that which increases the capacity of the light portion of the heart at the period of death only, is
 
proved by the fact that the difference between the two portions of the
 
organs varies with the cause of death, and that it increases in a direct
 
ratio with the increase of the obstacle to the circulation of the blood in
 
the lungs. Thus, in those animals killed by drowning, hanging, and
 
suffocation, Colman has found the right ventricle generally twice
 
the size^of the left, although its proportions commonly mentioned are
 
much smaller.(4) In fact, Haller asserts that in one subject he found
 
it three times as large as the left, (5) but the usual estimates are much
 
less than this. Gordon says the relation is sometimes as 5 : 4,(6) Lieberkühn as 3 : 2,(7) Portal as 7 : 5,(8) Helvetius(9) and Legallois,(10)
 
 
 
(1) Weiss, loc. cit. — Sabatier, loc. cit.
 
 
 
(2) Sabatier, loc. cit.
 
 
 
(3) Haller, Elem. phys., vol. ii. p. 134.
 
 
 
(4) On suspended respiration from drowning, hanging , and suffocation, London,
 
1791.
 
 
 
(5) Loc. cit., p. 133.
 
 
 
(6) System of human anat., vol. i. p. 38.
 
 
 
(7) Hamberger, Physiologie , p. 708.
 
 
 
(8) Mem. de Paris, 1770, p. 245.
 
 
 
(9) Loc. cit.
 
 
 
(10) Did. des sc. méd. vol. v. p. 440.
 
 
 
 
 
ANGEIOLOGY.
 
 
 
 
 
197
 
 
 
 
 
as 6 : 5, Brown Langrish as 11 : 10.(1) Gordon lias found the two
 
ventricles nearly equal in some cases, (2) and Portal asserts that their
 
capacity is the same in young people. (3)
 
 
 
These differences in the estimates of authors furnish a new argument against the common opinion, since we should presume that they
 
depend on greater or less accidental obstacles to the pulmonary circulation.
 
 
 
We cannot however deny but that the capacitj^ of the right portion
 
of the heart is a little greater than that of the left, because the blood
 
brought by the vena cava has received the fluid contained in the thoracic canal. It is also proved by the difference relative to the age in
 
the degree of disproportion, this being, directly after birth, less than at a
 
more advanced period of life. (4)
 
 
 
Legallois has also found the right portion of the heart a little broader
 
than the left in every kind of death, both after strangulation and from
 
the loss of blood.(5) The facts related prove only that the right portion of the heart can contract as much as, and even more than the left,
 
in certain circumstances, and that the left is also susceptible of becoming
 
larger than the light, but not that the capacity of the latter exceeds
 
that of the former during life.
 
 
 
4th. The fibres of the right side, especially those of the ventricle,
 
are not arranged in the same manner as those of the left side.
 
 
 
a. The thinness of the right ventricle is attended also with fewer
 
fibrous layers, a fact already pointed out by Senac,(6) but which Wolff
 
has indicated more precisely in saying that the right ventricle is
 
formed of three layers only, while that of the left side presents six,
 
counting the fleshy fasciculi of its internal face. (7) We have not
 
however been able to find this number of laj'ers. Usually we have
 
observed on each side only three distinct layers, two oblique, and one
 
internal longitudinal.
 
 
 
b. The fibres of the right ventricle are flatter and thinner than those
 
of the left. Thus the former form flattened fasciculi, and the second
 
rounded and thicker fasciculi. The latter ramify more ; they are
 
separated by fat, and have spaces between them, while we can hardly
 
distinguish the former from each other except by the direction of
 
their fibres.
 
 
 
e. The fibres of the right ventricle are more oblique and annular,
 
while those of the left are more longitudinal.
 
 
 
d. The layers of the right ventricle, although thinner, are much
 
more distinct than those of the left ventricle ; besides the latter are still
 
 
 
(1) De part.corp hum. fabric., vol. ii. p. 133.
 
 
 
(2) Loc. cit., p. 33.
 
 
 
(3) Doc. cit.
 
 
 
(4) Portal, loc. cit.
 
 
 
(5) TV. du cœur, vol. i. p. 200.
 
 
 
(6) De stratis ßbrarum cordis in Universum, in the Nov. act. Petrop. vol. iii. an
 
1785, p. 234-238.
 
 
 
(7) Loc. cit., p. 234.
 
 
 
 
 
198
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
more similar in regard to direction, which doubtless contributes to make
 
the left ventricle firmer, bat proves at the same time that we should
 
exercise some judgment in determining the number and direction of
 
these layers. Such at least is the positive result of our researches.
 
This also is the opinion of Wolff himself, who has studied the arrangement of the heart with too much exactness.
 
 
 
5th. The primitive form of the heart, that of a canal curved on
 
itself, is more evident in the left ventricle than in the right.
 
 
 
6th. The nerves of the left side are larger and more numerous than
 
those of the right side.
 
 
 
 
 
CHAPTER II.
 
 
 
SPECIAL REMARKS ON THE HEART.
 
 
 
§ 1304. We usually describe first the right half of the heart ; and in
 
order to follow the direction of the circulation of the blood, we begin
 
with the right auricle.
 
 
 
I. RIGHT AURICLE.
 
 
 
§ 1305. The right auricle ( atrium anterius , s. venarum car arum ,
 
s. der truin'), forms that portion of the base of the heart situated farthest
 
on the right and forward.
 
 
 
Its form is almost square ; the vena cava superior descends obliquely
 
from right to left, and from behind forward, towards its upper and
 
right angle, and the vena cava inferior ascends in a contrary direction
 
towards its lower and right angle. Notwithstanding this difference
 
in the direction of the two venæ cavæ, we must admit that they unite
 
and form a single trunk in the cavity of the auricle, for they unite on
 
the right forward and backward, and the absence of the left side of
 
their circumference is only apparent, since this side in fact exists, but
 
is dilated to produce the muscular part of the auricle. The upper and
 
left angle of the latter extends into a small blunt appendage, formed
 
like a rounded square, which is observed before the lower paît of the
 
aorta. The lower and left angle is rounded.
 
 
 
We observe transverse fibres on all the circumference of this auricle,
 
directly below the inner membrane of the heart, which, becoming
 
thinner and separating from each other above and below, are prolonged
 
for a small distance around the superior and inferior venæ cavæ.
 
They are thinner where they surround the point of union of the two
 
venæ cavæ forward, and are extended more uniformly, and are smoother
 
on the right side, both on thsir outer and on their inner face.
 
 
 
But the left part of the posterior face of the anterior and unattached
 
wall of the right auricle, which is the most extensive, is uneven internally. This unevenness depends on much larger and transverse fasci
 
 
 
ANGEIOLOGY.
 
 
 
 
 
199
 
 
 
 
 
culi, which are united by other smaller oblique fasciculi, so as to present a reticulated appearance. These fasciculi, with which the transverse fibres of the auricle are united, appear between two longitudinal
 
smooth bands which proceed only along its internal face. One of
 
these tw'o bands, the left, descends a short distance from the anterior
 
part of the venous orifice of the left ventricle ; the other, the right,
 
situated almost in the centre of the anterior wall, a little however to
 
the right, descends toward the left side, along the union of the two
 
venæ cavæ. These fleshy fasciculi have been called the pectinœal
 
muscles (AT. pectinati ) .
 
 
 
The posterior wall of the right auricle forms the anterior face of the
 
interventricular septum. We discover in it several remarkable parts,
 
some of which belong to the history of the development of the heart.
 
 
 
On the right side and toward the centre is the fossa ovalis ( fossa
 
ovalis , s. valvula foraminis ovalis, s. vestigium foraminis ovalis), an
 
oblong and rounded depression, which varies much in size. This fossa
 
is very distinct from the posterior wall of the auricle at its upper part,
 
a little less so on its sides, especially on the right, and is generally
 
blended with it below, particularly on the right side. The more extensive it is, the less evident are the limits which separate it from the
 
other parts of the posterior wall. It however not unfrequently presents a similar arrangement even when it is very small.
 
 
 
Most generally it exactly fills the space between the edges of the
 
projection which surrounds it, and it is very tense, but not unfrequently
 
it is much larger, and forms a valve, the loose edge of which corresponds to the left auricle. We almost always observe a greater or less
 
depression above, between its extremity and the upper part of the projection which surrounds it. Very often also we see in this place one or
 
more openings by which the cavity of the two auricles communicate.
 
This arrangement is not constant, and it is entirely independent of the
 
extent either of the valve or of the depression, although it occurs particularly when the valve is very broad. Even when the openings are
 
large and numerous, they seldom descend below the central part of the
 
projection which surrounds the depression, so that the septum of the
 
auricles is complete in regard to the separation of the blood contained
 
in the two cavities.
 
 
 
This place, especially in its upper part, is the thinnest portion of the
 
septum and of the auricle generally. W T e however always observe
 
muscular fibres between the two layers of the internal membrane of
 
the heart, that of the right and that of the left auricle.
 
 
 
The projection which surrounds this depression is formed of reticulated muscular fibres. It is called the ring or the isthmus of Vieussens ( annulus , s. isthmus Vieussenii). Its right portion separates the
 
right and left halves of the septum. Although it does not project at
 
its lower part, it is however complete in this place also.
 
 
 
We observe in its circumference several openings of the cardiac
 
veins, called the foramina of Thebesius ( foramina Thebesii). At the
 
 
 
 
 
200
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
lower end of the inferior edge of the ring a circular fold of the inner
 
membrane of the right auricle commences, this is called the Eustachian
 
valve ) or the anterior valve of the foramen ovale ( valvula Eustachii , s.
 
foraminis ovalis anterior). { 1) This fold extends more or less to the
 
right, along the anterior part of the orifice of the vena cava ascendens
 
into the right auricle, so that its lower edge is concave and attached
 
while the upper is convex and loose within the right auricle. It imperfectly separates below the right and left halves of the right auricle.
 
 
 
This valve varies much in regard to size, form, and texture. It is
 
usually more perfect and proportionally larger in the fetus than at any
 
time after birth. In the adult it is often entirely changed, at least at
 
its upper part, into a reticular tissue, and in many cases some filaments
 
only trace the valve, and these frequently do not exist. It usually
 
contains some muscular fibres, but it is often only a simple fold of the
 
internal membrane.
 
 
 
An intimate relation generally exists between the Eustachian valve
 
and the fossa ovalis, the former being more developed in proportion as
 
the septum formed by the latter between the two auricles is less perfect, and vice versa ; but to this rule there are numerous exceptions.
 
 
 
The valve acts principally in the fetus. At this period of life it conducts the blood of the vena cava superior toward the opening of the
 
septum or the foramen ovale. Hence the relation between it and the
 
valve of this opening.
 
 
 
In the adult it may prevent to a slight degree the reflux of the blood
 
from the vena cava superior, and from the right auricle generally into
 
the vena cava inferior. Directly at the left side of the left branch of
 
the isthmus of Vieussens, between this branch and the venous orifice
 
of the right ventricle, there is a large and rounded opening, the orifiee
 
of the large coronary vein of the heart ( orificium venae coronariœ cordis
 
magnœ).{ 2) This opening is sometimes divided more or less distinctly
 
into several, and generally is more or less perfectly closed by a valvular
 
fold, which arises at its lower part. This fold, called the valve of Thebesius ( valvula Thebesii), has its upper and .concave edge unattached,
 
while its lower and convex edge adheres. Sometimes it does not exist
 
in other cases it is replaced by one or more imperfect transverse bands ;
 
finally, in some subjects there are several, even as many as six, situated
 
one behind another.
 
 
 
(1) Winslow, Description d'une valvule singulière de la veine cave inferieure , à
 
l'occasion de laquelle on propose un sentiment nouveau sur la fameuse question du,
 
trou ovale , in the Mém. de Paris -, 1717, p. 272. Eclaircissement sur un Mèm.de 1-717,
 
Ibid. 1725. — Haller, De valvulâ Euslacliii, Gottingen, 1737. — L. Crell, De valvulâ
 
venœ cavœ Eustachianä, Wittenberg-, 1737.- — Brencle), De valvulâ Eustachianâ inter
 
venam inferiorem dextramque cordis auriculam positâ, Wittenberg, 1738. — Haller,
 
De valvulâ Eustachii prog.r. ii. Gottingen, 1748. — J. M. Diebolt, De foramine ovali,
 
Strasburg, 1771. — J. F. Lobstein, De valvulâ Eustachii , Strasburg, 1771. — C. F.
 
Wolff, De foramine ovali cjusque usu in dirigendo sanguinis motu observationes
 
novœ, in the N. C. Pctrop, vol. xx. p. 357. — H. L. Leveling, De valvulâ Eustachii et
 
foramine ovali, in the Obs. anal, rar f asc. i. 1786.
 
 
 
(2) Wolff, De orificio venœ coronariœ magnee ; in the Act. P elrop. 1777, p. 234-257.
 
 
 
 
 
ANCEIOLOGY.
 
 
 
 
 
201
 
 
 
 
 
II. RIGHT VENTRICLE.
 
 
 
§ 1306. The anterior , pulmonary, or right ventricle ( ventriculus anterior, s. dexter , s. pulmonalis ) is composed of an upper and lower portion, which are separated bj the upper part of the venous valve. The
 
former unites directly to the right auricle, the latter to the pulmonary artery, and its walls are thinner than those of the former. It
 
terminates in a conical extremity, which projects upward and backward
 
above the left ventricle and the septum of the heart. The pulmonary
 
artery arises from this part.
 
 
 
The internal or posterior wall is formed by the septum of the heart
 
and is slightly convex ; the anterior is still more so. The posterior
 
wall is smoother than the anterior at its upper portion and very often
 
entirely so below the arterial opening. The net-woik formed by the
 
projecting muscular fasciculi is much more complete toward its summit than toward its base.
 
 
 
The anterior wall of the pulmonary ventricle is thinnest above toward
 
the septum and thickest below also near the septum. Its thickness
 
when the heart is strong and not very much distended is more than
 
two lines, but less than this in the latter point. The two parts are
 
scarcely a line thick even in those hearts which are neither very much
 
distended nor small.
 
 
 
The quantity of blood in the right ventricle after death varies from
 
one ounce and a half to three ounces.
 
 
 
§ 1307. The venous valve of the right auricle arises from the circumference of its venous orifice. It is called the tricuspid valve ( val vida triglochis , tricuspis ), because, although it forms a single membrane,
 
it is higher in three points than in the short spaces between them, and
 
thus three slips are formed.
 
 
 
Of these, one, which is the largest, arises from the external and anterior part of the circumference of the venous orifice. The other two
 
are smaller and arise from the inner and posterior part of this circumference, one over the other ; so that consequently there is an external
 
and larger slip, and two internal, an upper and a lower slip.
 
 
 
The last two are separated from each other by a space not so deep
 
as those between them and the external. It is then more correct to
 
admit only two slips, an anterior and external and a posterior and
 
internal.
 
 
 
The first is much higher than the second.
 
 
 
The tendinous filaments of the upper extremity of the anterior or
 
external slip are attached to this upper part of the septum. They are
 
few in number. We usually find in the space only one or at most two
 
short muscles, to which are attached those filaments farthest to the
 
left ; the others are inserted in its smooth wall. Most of those
 
filaments which come from the central and lower parts of the edge of
 
 
 
 
 
VOL. II.
 
 
 
 
 
26
 
 
 
 
 
202
 
 
 
 
 
DESCRIPTIVE ANATOMY.
 
 
 
 
 
this slip are attached to the summits of five or six of the fleshy pillars
 
coming from the middle and lower parts of the anterior wall.
 
 
 
The filaments which arise from the posterior slips are mostly attached
 
to the smooth folds of the septum, except a few, which are inserted in
 
two or three small fleshy pillars, all of which except the lowest come
 
from the septum.
 
 
 
The arterial orifice generally extends about three fourths of an inch
 
higher than the venous. The sigmoid valves are thin. Their tubercles
 
( noduli Morgagnii ) are slight swellings, which however are often well
 
marked in the young fetus.
 
 
 
III. LEFT AURICLE.
 
 
 
§ 1308 . The left, posterior, or pulmonary auricle (atrium sinistrum ,
 
s. posterius, s. venarum puhnonalium, s. aorticum) is of an oblong square
 
form, considerably more broad than high.
 
 
 
It is separated below and posteriorly from the left ventricle by a circular groove, upward and to the right from the right ventricle by a similar
 
depression. The pulmonary artery, the aorta, and the vena cava superior
 
are also found upward and outward, between it and the right ventricle ;
 
so that the external part of its right and left extremities is alone visible.
 
 
 
Its upper left angle rises into an auricular appendage ( auricula sinis tra ), which goes forward to the left and upward, directly behind the
 
pulmonary artery, separating very much from the rest of the auricle.
 
This appendage, which is narrower, longer, and on the whole larger
 
than that of the right auricle, is circumscribed by rougher edges. It
 
curves three or four times and finally terminates in a sharp summit,
 
below and before the pulmonary artery.
 
 
 
The posterior wall of the lower part, the sinus of the auricle (sinus
 
venarum puhnonalium), receives where it is continuous with the lateral
 
parietes the four pulmonary veins, two on each side, the upper being
 
larger than the lower. One of the two veins of the same side opens
 
directly above the other, while between those of the two opposite sides
 
is the whole breadth of the auricle ; so that the two pairs occupy the
 
whole height of the posterior wall.
 
 
 
The parietes of the whole auricle are muscular and formed principally
 
of transverse fibres. They are smooth with the exception of the appendage. We observe in its whole length an anterior and a posterior
 
series of very prominent transverse fasciculi, united by other smaller
 
and oblique fasciculi, which proceed between two longitudinal bands,
 
situated one on the right the other on the left.
 
 
 
The anterior wall is formed by the septum of the auricles and is also,
 
like the posterior face of the septum, irregular in another respect. In
 
fact we there observe a constant semicircular valve, which is however
 
more or less developed. This valve leaves the upper edge of the transparent point which corresponds to the fossa ovalis of the right auricle
 
(§ 1305 ). It is turned upward and toward the left. Its lower edge
 
 
 
 
 
ANGEIOLOGY.
 
 
 
 
 
203
 
 
 
 
 
is convex and attached, and its upper edge is loose in a greater or less
 
extent. Sometimes there is only a slight projection in its place.
 
 
 
This valve extends behind the interauricular septum. Its lower edge
 
is attached to the posterior face of the centre of the isthmus of Vieussens, and the space between it and this isthmus forms a small cavity
 
( sinus septi ), which terminates below in a cul-de-sac. This is only the
 
upper part of the valve of the foramen ovale (§ 1305), which in the
 
normal state always ascends on the posterior face of the isthmus. Of
 
this we are readily convinced when it does not adhere to the isthmus
 
in the centre ; for then the continuity is totally uninterrupted.
 
 
 
IV. LEFT VENTRICLE.
 
 
 
§ 1309. The left ventricle (venir i cuius sinister ) posterior, s. aorticus )
 
is the strongest of all parts of the heart and forms its figure. Its posterior wall and its anterior wall which forms the posterior face of the
 
septum, are convex externally and concave internally : so that its whole
 
form is oval. The internal face of the posterior wall is very much
 
reticulated ; the anterior wall is smooth at its upper part and reticulated
 
in the lower, but less so than the posterior wall. The fleshy pillars
 
are rounded.
 
 
 
The thickness of the parietes is less toward the summit and greater
 
at the base than in all other parts. In the adult it is five or six lines
 
thick at the base and only three at the summit.
 
 
 
The capacity of the left ventricle varies in the adult from eight to
 
twenty drachms.
 
 
 
§ 1310. Before the round venous orifice we find the mitral valve
 
( valvula mitralis), composed of an upper and a lower slip. The upper
 
arises directly below or rather before the ring of the sigmoid valve of
 
the aorta, and is attached by slips to three or four fleshy pillars, which
 
all come from the internal face of the posterior wall of the ventricle, some
 
above, others below, and among which we distinguish two particularly,
 
an upper and a lower, which are much larger than the others. The
 
inferior and external slip, which is much narrower, is attached by tendinous filaments to a short but very thick fleshy pillar.
 
 
 
All these fleshy pillars arise from the posterior wall of the left ventricle ; so that those of the upper slip arise near the summit of the