FOREARM AND HAND 159 



branch to the third lumbrical muscle. In the palm the 

 digital branches of the median nerve pass distally deep to 

 the superficial volar arch and its digital branches, but as they 

 approach the fingers they become superficial to the digital 

 arteries. Further, it should be noted that those branches 

 of the median nerve which supply the adjacent sides of 

 fingers divide at a more proximal level than that at which 

 the digital arteries divide. 



As they run along the sides of the fingers the digital 

 nerves send branches to the skin of the whole of the volar 

 aspect, and to the skin of the dorsal aspects of the second 

 and third phalanges. At the extremity of the finger each 

 nerve of supply divides into two branches. One of the two 

 ramifies in the pulp of the finger and the other passes dorsally 

 to the bed of the nail. 



If the dissector exercises sufficient care in the dissection 

 of the branches of the digital nerves he will find minute oval, 

 seed-like bodies attached to the smaller twigs. They are 

 special sensory end organs called Pacinian Bodies. 



It follows, from what has already been pointed out, that, 

 in the region of the hand, the median nerve supplies five 

 muscles and the skin of three and a half digits. The 

 muscles are the abductor pollicis brevis, the opponens 

 pollicis, the superficial head of the flexor pollicis brevis and 

 the two most lateral lumbrical muscles ; the digits are 

 the pollex, the index, the medius and the radial half of the 

 annularis. 



Nervus Ulnaris. The palmar continuation of the ulnar 

 nerve enters the palm by passing superficial to the transverse 

 carpal ligament. As it lies secure from the effects of pressure, 

 under the shelter of the pisiform bone and upon the medial 

 side of the ulnar artery, it divides into two terminal branches 

 a superficial and a deep. 



The deep branch passes to the medial side of the hook of 

 the os hamatum and then dips, deeply, into the palm, with 

 the deep branch of the ulnar artery, through the cleft 

 between the abductor digiti quinti and the flexor digiti quinti 

 brevis. It supplies the short muscles of the little finger as 

 it passes between them, and afterwards gives branches to 

 numerous other muscles. Its further course and distribution 

 will be seen when the deep part of the palm is dissected 

 (p. 170). 



