THE BRACHIAL PLEXUS. 



1309 



Branches. These are : (a) the cutaneous, (<) the muscular, (c~) the humeral, 

 (d*} the articular and (<?) the terminal. 



FIG. i i oo. 



Scapular head of triceps 



Superior profunda artery 



Portion of external head of triceps, everted 



Muscular branch 



Olecranon 



Anconeus 

 Extensor carpi ulnaris 



Extensor longus pollicis 



' A 



Extensor indicis 



Musculo-spiral nerve 



Upper external cutaneous nerve 

 External head of triceps 



Brachialis anticus 



Lower external cutaneous nerve 



External condyle 



Extensor carpi radialis longior 



Extensor carpi radialis brevior 



Supinator brevis 



Posterior intei osseous nerve 



Extensor communis digitorum 

 Extensor minimi digiti 



Extensor ossis metacarpi pollicis 

 Extensor brevis pollicis 



Extensor longus pollicis 



Gangliform enlargement on 

 posterior interosseous nerve 



I \ 



Deep dissection of extensor surface of right upper extremity, showing course and 

 branches of musculo-spiral nerve. 



a. The cutaneous branches are three in number, an internal and two external. 



The internal cutaneous branch frequently arises from the musculo-spiral in common with 



