418 



ULNAR NERVE. 



The ULNAR NERVE is somewhat smaller than the median, behind wmcn 

 it lies, gradually diverging from it in its course. It arises from the bra- 

 chial plexus in common with the internal head of the median and the in- 

 ternal cutaneous nerve, and runs down the inner side of the arm, to the 

 groove between the internal condyle and olecranon^ resting upon the 

 internal head of the triceps, and accompanied by the inferior profunda 

 artery. At the elbow 7 it is superficial, and supported by the inner con- 

 dyle, against which it is easily compressed, giving rise to the thrilling 

 sensation along the inner side of the fore-arm and little finger, ascribed to 

 striking the " funny bone." It then passes between the two heads of the 

 flexor carpi ulnaris and descends along the inner side of the fore-arm, 

 crosses the annular ligament, and divides into two branches, superficial 

 and deep palmar. At the commencement of the middle third of the fore- 

 arm, it becomes applied against the artery, and lies to its ulnar side, as 

 far as the hand. 



The Branches of the ulnar nerve are 



Fig. 188.* 



Muscular in the upper arm, 



Articular, 



Muscular in the fore- arm, 



Anastomotic, 



Dorsal branch, 



Superficial palmar, 



Deep palmar. 



The Muscular branches in the upper arm are a 

 few filaments distributed to the triceps. 



The Articular branches are several filaments to 

 the elbow joint, which are given off from the nerve 

 as it lies in the groove between the inner condyle 

 and the olecranon. 



The Muscular branches in the fore-arm are dis- 

 tributed to the flexor carpi ulnaris and flexor pro- 

 fun dus digitorum muscle. 



The Anastomotic branch (n. cutaueus palmans 

 ulnaris) is a small nerve which arises from the ulnar 

 at about the middle of the fore-arm, and divides 

 into a deep and a superficial bxanch ; the former ac- 

 companies the ulnar artery, the latter pierces the 

 deep fascia, and is distributed to the integument, 

 'communicating with the posterior branch of the in- 

 ternal cutaneous nerve. 



The Dorsal branch passes backwards beneath the 

 tendon of the flexor carpi ulnaris, at the lower third 

 of the fore-arm, and divides into branches, which 

 supply the integument and two fingers and a half on the posterior aspect 

 of the hand, communicating with the internal cutaneous and radial nerve. 

 Tne Superficial palmar branch divides into three filaments, which are 



* A view of the nerves on the dorsal aspect of the fore-arm and hand. 1, 1. The ulnar 

 nerve. 2, 2. The posterior interosseous nerve. 3. Termination of the nervus cvitanous 

 tmmeri. 4. The dorsalis carpi, a branch of the radial nerve. 5, 5. A back view of the 

 digital nerves. 6*. Dorsal branch of the ulnar nerve. 



