364 
digit. 
THE MUSCLES OF THE PIG 
(2) The small volar muscle is the extensor digiti quinti proprius; it ends by 
a long tendon on the lateral aspect of the fifth digit. 
The supinator, when present, is a pale, thin muscular slip which arises on the 
lateral border of the radius just above the interosseous space, extends medially and 
Fic. 317.—Muscuies or AnTI- 
BRACHIUM AND Manus 
or Pic; Dorso-LaATERAL 
VIEW. 
a, a’, Extensor carpi 
radialis; 6, extensor carpi 
obliquus (s. abductor pollicis 
longus); c,d, e, common dig- 
ital extensor; c’, c’’, tendons of 
alah; 
tendons of e; f, 
insertion of c; tendons 
of dy 67,6", 
tendon of extensor digiti se- 
eundi; g, extensor digiti quarti; 
quinti; A’, 
tendinous, and 
h, extensor digiti 
tendon of h; 7, 
k, fleshy, part of ulnaris later- 
alis; k’, tendon of k; J, 
head of deep digital flexor; m, 
ulnar 
digital flexor; n, 
(After Ellenberger, 
superficial 
brachialis. 
in Leisering's Atlas.) 
downward across the dorsal surface of the bone to its medial 
border, where it blends with the radial head of the deep 
flexor. 
The pronator teres is a delicate, fusiform muscle which 
lies along the medial surface of the elbow and proximal part 
of the forearm. It arises from the medial epicondyle and 
collateral ligament of the elbow and is inserted by a thin 
tendon to the medial border of the radius about its middle. 
The flexor carpi radialis is well developed. It arises 
on the medial epicondyle of the humerus, and is inserted 
into the third metacarpal bone. 
The flexor carpi ulnaris is narrow and has no ulnar 
head. It runs obliquely down the back of the forearm in 
the furrow between the superficial and deep flexors of the 
digit. It arises from the medial epicondyle of the humerus 
and ends on the accessory carpal bone. 
The ulnaris lateralis (M. extensor carpi ulnaris) is 
covered by a tendinous band, which is a thickened part 
of the fascia of the forearm and extends from the lateral 
epicondyle to the accessory carpal bone and lateral aspect 
of the carpus. The belly of the muscle is round: its ten- 
don of insertion perforates this band in the distal part of 
the forearm and ends on the proximal end of the fifth 
metacarpal bone. 
The superficial digital flexor arises from the medial 
epicondyle of the humerus and consists of two parts. The 
tendon of the superficial head passes down behind the pos- 
terior annular ligament of the carpus (bound down by a 
special annular ligament), forms a ring at the fetlock for a 
tendon of the deep flexor, and ends by two branches on the 
second phalanx of the fourth digit. It receives a small 
band from the accessory carpal bone. The tendon of the 
deep head, after detaching a strong branch to the tendon 
of the deep flexor, passes down with the latter (for which 
it forms a ring), and ends on the third digit. 
The deep digital flexor has three heads—humeral, 
ulnar, and radial. The humeral head is very large and 
forms the greater part of the contour of the volar face of 
the forearm. 
It consists of two parts—a large superficial | 
part, and a much smaller deep part which arises with the | 
Each ends at the distal part of the fore- 
These unite and receive the ten- 
superficial flexor. 
arm on a short tendon. 
dons of the radial and ulnar heads and a branch from the 
superficial flexor tendon. 
thick, prismatic belly which arises from the medial surface of the proximal 
part of the ulna. 
joins the tendon of the latter at the level of the accessory carpal bone. 
It arises from the upper part of the medial border of the 
radius and from the deep fascia, and its tendon joins that of the humeral head at | 
The common tendon divides into four branches, 
radial head is small. 
the distal end of the forearm. 
Its long, thin tendon passes down on the humeral head and 
The 
The ulnar head has a short, — 
