358 NEUROLOGY, OR ANATOMY OF NERVOUS SYSTEM 



behind the clavicle and subclavius, lying on the subscapularis 

 and serratus magnus. The cords lie external to the first part 

 of the axillary artery, but on three sides of the second part 

 of that vessel. 



BRANCHES ABOVE THE CLAVICLE. A branch from the fifth 

 joins the phrenic, and muscular branches supply the scaleni, 

 longus colli, rhomboidei, and subclavius. The branch to the 



From 4th 



FIG. 64 



i Rhomboid 



Subelavian 



C. with Phrenic 



VII c, 



Branches to tonyus 

 Colit and Scaleni 



VIII 



Anterior division 

 oj Middle Trunk 



I Dorsal 



Sup rascapular 

 Upper Trunk 



Anterior division of Upper Trunk 



External Anterior Thoracic 

 Posterior division of Upper Trunk 

 Upper Sub-scapular 



Middle and Lower 

 Sub-bcapular 



Circumflex 



Lower Trunk 



Posterior division of Middle Trunk 



Posterior Thon 



A vti- 1 ioi- dirinion of Lower Trunk 

 Poxturiur dit ision of Lower Trunk 



Internal Anterior Thoracic 



Lesser Internal Cutaneous* 



Internal Cutaneous 



JHusculo-cutanetius 



Ulnar/ 

 Musciilo-spiral 



Plan of the brachiai plexus. (Gray.) 



subclavius, from the trunk formed by the fifth and sixth cervical, 

 crosses the subclavian artery, its third part, and sends a branch 

 to the phrenic nerve. 



The posterior thoracic nerve, from fifth and sixth cervical, 

 runs out of the scalenus medius and descends behind the clavicle 

 upon the serratus magnus, which it supplies. 



The suprascapular nerve, from the fifth and sixth, enters 

 the supraspinous fossa by the notch, supplies an articular 



