THE ANTERIOR LIMB. 215 
Middle portion: Ventral surface of the ulna. 
Ulnar portion: Medial epicondyle in common with (c). 
Insertion: By five tendons on the bases of the ungual 
phalanges. 
(f) The flexor carpi ulnaris. Origin: Medial epicondyle and 
medial surface of the olecranon, forming two short but 
separate heads. Insertion: Pisiform bone. 
7. Muscles arising from the bones of the hand and inserted on 
the individual digits: 
(a) The flexor digiti quinti. Origin: Pisiform bone and ten- 
don sheath of the flexor digitorum profundus. Insertion: 
Sesamoid bones of the metacarpophalangeal joint of the 
fifth digit, extending to the ungual phalanx. 
(b) The lumbricales. Origin: From the point of division of 
the tendon of the flexor digitorum profundus. Insertion: 
First phalanges of the second to fifth digits. 
(c) The interossei. Origin: In pairs from the bases of the 
second to fifth metacarpals and related portions of the carpal 
bones. Insertion: Sesamoid bones of the metacarpophalan- 
geal joints. 
BLOODVESSELS AND NERVES OF THE ARM AND FOREARM. 
The axillary artery gives rise to posterior and often anterior 
branches; the circumflex arteries to the head of the humerus 
and the deep artery which latter, arising in one or two branches 
and passing between the coraco-brachialis and teres muscles to 
the lateral surface of the shoulder, gives branches to the deltoideus 
and to the proximal ends of the lateral and long heads of the 
triceps. The deep artery continues on the lateral side of the 
medial head of the triceps and passes to the lateral head of 
the brachialis, near the elbow, as the radial collateral artery. 
*The brachial artery (a. brachialis), the continuation of the 
axillary, passes distad on the medial surface of the arm between the 
biceps and the anconaeus medialis. Crossing to the anterior sur- 
face of its distal extremity, it passes beneath the head of the 
pronator teres to the medial surface of the radius, dividing at this 
