THE PERIPHERAL NERVOUS SYSTEM. 



337 



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

 terior thoracic (;), the three subscapular nerves (c, e, and z), 

 the axillary ((), musculocutaneus (/), radial (//), and median 

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



V 



m 



FIG. 159. DIAGRAM OF THE RIGHT BRACHIAL PLEXUS. 

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

 nerve, a, phrenic nerve; b, suprascapular; b' , nerve to serralus anterior and levator 

 scapulae muscles; c, first or cranial subscapular nerve; d, axillary nerve; e, second 

 subscapular ; f, musculocutaneous; g, median; h, radial; i, third subscapular;/, ulnar; 

 k, second anterior thoracic; /, medial cutaneous; in, posterior thoracic; n, first 

 anterior thoracic. 



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

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

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

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

 median cutaneous nerve (7) and parts of the radial (//), ulnar 

 (/), 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, h, 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. 

 1 60, 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. 

 1 60, s) and sometimes also to the latissimus dorsi (?). 



