108 ANATOMY OF UPPER EXTREMITY, ETC. 



The two following nerves are extremely liable to be removed wit 

 the flap of integument, their small size and superficial position It 

 ing to their division as they lie unnoticed in the cellular tissue. 



The INTERNAL CUTANEOUS NERVE arises in comra< 

 with the internal head of the median nerve ; it passes d 

 the arm by the side of the basilic vein, giving off cutaneous 

 filaments in its course, and divides into two principal 

 branches, both of which are distributed to the integumei 

 of the forearm along its inner and anterior aspect. 



The LESSER INTERNAL CUTANEOUS NERVE, or NERVE OF 

 WRISBERG, is the smallest nerve of the arm ; it is found 

 inside of the internal cutaneous nerve, and is distribute 

 to the integument of the lower and inner part of the an 

 Just below the axilla, this nerve communicates with tl 

 inter costo-humeral nerve, a branch of the second intercosl 

 nerve, stretching across from the thoracic parietes to tl 

 axilla. A second intercosto-humeral nerve, from the thii 

 intercostal, sometimes exists. 



The CIRCUMFLEX NERVE is a large trunk which cross* 

 the tendon of the sub-scapularis to pass directly underneath 

 and around the head of the humerus, in company with the 

 posterior circumflex artery; it gives branches to the deltoid, 

 the neighboring integument, and to all the muscles of the 

 scapular region. Its sudden turn, and the shortness of its 

 trunk before disappearing behind the humerus, sometimes 

 embarrass the dissector in his search for this branch of th( 

 brachial plexus. 



The MUSCULO-SPIRAL NERVE arises in common with th( 

 circumflex; it passes behind the brachial artery, and winds 

 spirally round the humerus, in company with the superi< 

 profunda artery, to reach the outer side of the arm, whei 

 it lies deep between the brachialis anticus and supinatc 

 longus muscles, and divides into two branches radial ai 

 posterior interosseous. 



The MEDIAE NERVE arise*s by two heads, which, in tl 

 axilla, embrace the brachial -artery; these form a trunk oi 

 large size which lies at first on the outer side of the vessel, 

 afterward on its inner side, and descends without any 

 branches to the bend of the elbow, where it gives off some 

 muscular branches and the anterior interosseous nerve ; it 

 then continues down the forearm to the hand. 



The ULNAR NERVE arises in common with the internal 

 head of the median, and internal cutaneous nerves, and de- 

 scends without branches upon the inner side of the brachial 

 artery, to the hollow between the inner condyle and olecra- 



;: 





