THE BRACHIAL PLEXUS. 



1309 



Branches. — These are : (a) the cufafieous, (d) the musai/ar, (c) the humeral, 

 {d^ the articular and («') the terminal. 



Fig. I 100. 



 • -:/ 



Scapular head of triceps - 



Superior profunda artery . 



Portion of external head of triceps, everted - 



Muscular branch - 



-Musculo-spiral nerve 



Upper external cutaneous nerve 

 E.xternal head of triceps 



- Brachialis anticus 



-Lower external cutaneous nerve 



Olecranon - 



Anconeus • 

 Extensor carpi ulnaris 



Ih 



- External condyle 



-Extensor carpi radialis longior 



-Extensor carpi radialis brevior 



-Supinator brevis 

 -Posterior interosseous nerve 



Extensor longus poUicis. 



-Extensor communis digitorum 

 -Extensor minimi digiti 



Extensor indicis- 



-Extensor ossis metacarpi pollicis 

 -Extensor brevis pollicis 



-Extensor longus pollicis 



-Gangliform enlargement on 

 posterior interosseous aerve 



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 



