20 



TOPOGEAPHICAL ANATOMY OF 



Only one branch leaves the median nerve while it is in the arm. 

 This arises about the middle of the arm and at once sinks between 

 the coracobrachial and biceps muscles. It then continues obliquely 

 between the brachialis and biceps, supplying branches to the former 

 muscle, crosses the flexor aspect of the elbow joint, and thus gains the 



A. thoracoacromialis.- 



M. supraspinatus. . 

 M. subscapularis. -' 



N. musculocutaneus.- 



M. coracobrachial is. 

 N. medianus. 



M. biceps brachii. 



M, brachialis.- 



A. coUateralis radialis 



M. biceps brachii. 

 M. extensor carpi radialis. 



^-•A. circumflexa scapulse, 



,-A. subscapularis. 

 ^ A, thoracodorsals s. 



- JN'. radialis. 



_ - - - - A. circumflexa humeri 

 posterior. 



M, teres major. 



- - M. triceps brachii 

 (caput longum). 



- - A. profunda brachii. 



N. ulnaris. 



M. triceps brachii 

 (caput mediale). 

 A. coUateralis ulnaris. 



M. flexor carpi ulnaris. 

 M. flexor carpi radialis. 



Fig. 10. — Deep Dissection of the Medial Aspect of the Arm. 



forearm, where it will be seen later as one of the cutaneous nerves of 



the region (n. cutaneus antibrachii lateralis). Although, for the sake 



of convenience and because of its obvious origin, this nerve is here 



described as a branch of the median, there is reason for assuming that, 



morphologically, it is part of the musculocutaneous nerve. The fibres 



composing it apparently become separated from the other components 



of the musculocutaneous during the temporary fusion of this nerve 



with the median. ^. .^. ..,„. ^^ ^ 



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