152 ANATOMY OF UPPER EXTREMITY, ETC. 



sides of the base of the first phalanx of the thumb, the 

 inner being united with the adductor pollicis, and the outer 

 with the abductor pollicis ; a sesamoid bone is connected 

 with each at its insertion. A branch from the median 

 nerve supplies the outer part of the flexor and the abductor 

 and opponens pollicis muscles. 



The examination of the adductor pollicis muscle is 

 necessarily deferred to a later period of the dissection. 



The palmaris brevis being removed, the most superfici 

 of the remaining muscles of the little finger is the AB- 

 DUCTOR MINIMI DIGITI ; it arises from the pisiform bone 

 and the tendon of the flexor carpi uhiaris, and is inserted 

 into the ulnar side of the base of the first phalanx of the 

 little finger. This muscle may arise from the fascia of the 

 forearm with a length of four inches. A branch from the 

 ulnar artery, called the communicating, and a deep branch 

 of the ulnar nerve, pass between this muscle and the one 

 beneath it. 



The FLEXOR BREVIS MINIMI DIGITI lies beneath the 

 preceding, of which it appears to be a part ; it arises from 

 the unciform bone and from the annular ligament, and is 

 inserted into the*base of the first phalanx of the little 

 finger. This muscle is sometimes wanting. 



The FLEXOR Ossis METACARPI, ADDUCTOR, or OPPONENS 

 MINIMI DIGITI is partty overlaid by the preceding muscles; 

 it arises from the annular ligament and from the process of 

 the unciform bone, and is inserted into the whole length of 

 the metacarpal bone of the little finger. 



The continuation of the ulnar artery in the palm of the 

 hand is called the superficial palmar arch ; it is covered in 

 by the palmar fascia, and lies across the flexor tendons of 

 the fingers and the digital branches of the median nerve ; it 

 gives off a deep communicating branch, which passes be- 

 tween the abductor and flexor minimi digiti, to inosculate, as 

 will be seen hereafter, with the deep arch of the radial artery ; 

 it supplies both sides of the three inner fingers, and one 

 side of the index finger, with digital branches ; these arise 

 opposite the interosseous spaces by single trunks, which 

 bifurcate to supply the contiguous sides of two fingers, 

 those of the same finger uniting at its extremity; the 

 branch to the outer side of the little finger arises singly. 

 Near the roots of the finger the digital arteries receive 

 communicating branches from the deep arch ; but the artery 

 to the little finger gets its communicating branch from the 



