THE PERIPHERAL NERVOUS SYSTEM. 



387 



or both of the anterior thoracic nerves (^k and ;/), of the pos- 

 terior thoracic {in), the three subscapular nerves (r, c, and 2), 

 the axillary {d), musculocutaneus (/), radial {h), and median 

 {g) nerves. The eighth cervical ( VIII) supplies parts of one 



V 



Fig. 159. — Diagram ok the Right Brachial Plexus. 

 V, VI, VII, VIII, the fifth to eighth cervical nerves, i, the first thoracic 

 nerve, a, phrenic nerve; /', sujirascapular; h' , nerve to serralus anterior and levator 

 scapulas muscles; c, first or cranial subscapular nerve; d, axillary nerve; <r, second 

 subscapular;/^ musculocutaneous; .^, median; //, radial; /, third subscapular;/, ulnar; 

 k, second anterior thoracic; /, medial cutaneous; m, posterior thoracic; ii, lirsi 

 anterior thoracic. 



of the anterior thoracic nerves {k), the caudal one of the sub- 

 scapular nerves (/), the radial (//), median {g), and ulnar {j) 

 nerves. The first thoracic (1) curves craniad, so as to leave 

 the thorax on the cranial side of the first rib; it supplies the 

 median cutaneous nerve {I) and parts of the radial (//), ulnar 

 (y), and median {g) nerves; sometimes also a part of one {k) 

 of the anterior thoracic nerves. 



The following are the nerves which arise from the brachial 

 plexus : 



A. Nerves of the Shoulder and Breast (Fig. 160). 



I. Nn. thoracici anteriores. — There are two anterior 

 thoracic nerves. One (Fig. 160, //, Fig. 159, ;/) arises from the 

 seventh cervical and passes to the pectoral muscles (9) along 

 with the anterior thoracic artery. The other (Fig. 159, k\ Fig. 

 160, q and r) arises usually by two roots, one from the eighth cer- 

 vical, one from the first thoracic ; it passes along with the long 

 thoracic artery to be distributed to the pectoralis muscles (Fig. 

 160, 8) and sometimes also to the latissimus dorsi (7). 



