740 NERVES OF THE ARM. 



quadratus, after supplying it, it goes through the inter- 

 osseous ligament to the back of the hand. At the wrist 

 the median sends a branch over the annular ligament to 

 the integuments on the ball of the thumb and palm of the 

 hand, called the superficial palmar. 



In the palm, as stated, the median divides into digital 

 branches, which are five in number. The first two go along 

 on either side of the thumb, the third along the radial side 

 of the fore finger, the fourth divides and runs along the 

 adjacent sides of the fore and middle fingers, and the fifth 

 also divides to supply the adjacent sides of the middle and 

 ring fingers. A muscular branch is also seen going from 

 the median to the muscles of the ball of the thumb. These 

 digital nerves all accompany the digital arteries. 



The ulnar nerve (Fig. 235) comes from the lower part of 

 the plexus and descends along the anterior and internal 

 part of the triceps to the inner condyle, between which 

 and the olecranon it passes. It also goes between the two 

 heads of the flexor carpi ulnaris, and gets to the front of 

 the forearm, along the ulnar edge of which it descends to 

 the wrist ; here it passes over the annular ligament, adja- 

 cent to the pisiforme bone, and in the palm of the hand 

 divides into a superficial and deep branch. 



To the various muscles along its course muscular branches 

 are given off. A little above the wrist it sends off the 

 dorsalis carpi, which gets to the back of the wrist beneath 

 the tendon of the flexor ulnaris, to supply the integuments 

 on the back of the hand and the two last fingers. The 

 superficial terminating branch of the ulnar divides so as to 

 supply both sides of the little finger and the ulnar side of 

 the ring finger. There is also a branch communicating 

 with the median. The deep branch dips beneath the flexor 

 tendons to form the deep palmar arch and to supply the 

 interossei muscles. 



The radial or musculo-spiral nerve (Fig. 235) comes from 

 different parts of the axillary plexus. It is a large nerve, 

 and descends obliquely outward round the humerus along 

 with the superior profunda artery, between the triceps 



