Spinal Nerves. 



153 



N. ULNAR. 



N MEDIAN. 



N.INTEROSS.INT. 



.flexor poll. 

 ' brevis 



497. The Nerves at the Palmar Side of the Hand. 



6. Ulnar nerve, JV. ulnar is, arises from the inner cord of the 

 brachial plexus, lies at first to the inner side of the axillary artery and 

 vein, pierces the internal intermusc'ular septum, passes down between the 

 inner condyle of the humerus and olecranon, then between the two heads 

 of the M. flexor carpi ulnaris, runs between it and M. flexor digitorum profundus, 

 and passes on the inner side of the ulnar artery to the wrist. It supplies 

 the M. flexor carpi ulnaris and inner half of the M. flexor profimdus digitorum 

 and with a cutaneous branch, the ulnar side of the forearm. Above the wrist 

 it divides into a dorsal and palmar branch, R. dorsalis and E. volaris. 



The dorsal branch passes to the back of the hand, pierces the 

 fascia and divides into five digital branches, Nervi digitorum dorsales, 

 which supply both sides of the little and ring fingers and the ulnar side of 

 the middle finger, down to the second phalanges. The palmar branch 

 passes by the side of the pisiform bone above the annular ligament into the 

 palm of the hand and divides into a superficial and a deep branch, 

 R. superficialis and R. profundus. The former sends branches to the ulnar side 

 of the little finger, and adjoining sides of the little and ring fingers; the 

 latter supplies the muscles of the little finger, the MM. interossei, the M. lum- 

 bricatis IV, Adductor pollicis and inner head of the M. flexor brevis pollicis. 



