ULNAE NEBVE 



817 



Ulnar Nerve 

 The ulnar nerve (Figs. 566, 567, 568, 652) arises with the median from the 

 thoracic components of the brachial plexus. It descends between the brachial 

 artery and vem, accompanied for a short distance by the radial nerve. It then 

 crosses the vem and continues behind the latter along the anterior border of the 

 tensor fascise antibrachii and dips under that muscle near the elbow. Here it is 

 jomed by the ulnar vessels and passes downward and backward over the medial 

 epicondyle of the humerus. In the forearm it crosses obliquely the deep face of the 

 ulnar head of the flexor carpi ulnaris and descends under the deep fascia with the 



Extensor carpi radialis 



Intermuscular sept 



Common extensor of digit 



Intermuscular septum 



Lateral extensor of digit 

 Intermuscular septum 



Uhiaris lateralis 

 Deep digital flexor 

 {humeral head) 



Superficial digital flexor 



Deep digital flexor (ulnar head) 



Ulnar vein Ulnar nerve 



Ulnar artery 



Fig. 653. — Cross-section of Fohearm of Horse about Three Inches (ca. S cm.) below the Elbow Joint. 

 The deep fascia ia designated by red line. N, A, V, Interoaseoua vessela and nerve. 



Accessory cephalic vein 



Vein 



Cephalic vein 

 Medial ligament of elbow 



Median nerve 

 Median veins 

 Median artery 



Flexor carpi radialis 



Flexor carpi ulnaris 



vessels, at first on the ulnar head of the deep flexor, and then between the middle 

 and lateral flexors of the carpus. Near the level of the accessory carpal bone it 

 divides into two terminal branches, superficial and deep. It gives off two principal 

 collateral branches. The cutaneous branch (Ramus cutaneus volaris) is detached 

 just before the nerve passes under the tensor fascise antibrachii; it runs downward 

 and backv/ard on that muscle under cover of the posterior superficial pectoral, 

 becomes superficial below the elbow, and ramifies on the posterior surface and both 

 sides of the forearm. The muscular branches, which are given off at the elbow, 

 supply the superficial digital flexor, the ulnar head of the deep flexor, and the flexor 

 carpi ulnaris. Of the two terminals, the superficial branch (Ramus superficialis) 

 emerges between the tendons of insertion of the lateral and middle flexors of the 

 carpus and ramifies on the dorso-lateral aspect of the carpus and metacarpus. The 

 deep branch (Ramus profundus), after a verv short course, unites under cover of 

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