UPPER NINE SPINAL NERVES. 495 



ifitertexture surrounds the axillary artery somewhat like the 

 braids of a whip-cord, from the clavicle to the os humeri below 

 its head. In this course the axillary plexus passes along with 

 the artery between the subclavius muscle and the first rib, lies 

 in contact with the superior part of the serratus major arrficus 

 muscle, and immediately below the articulation of the shoulder 

 joint. The axillary vein is- in front of it. 



The nerves which proceed from the axillary plexus are the 

 Scapular; the thoracic; the Axillary; the two cutaneous; the 

 Radial ; the Ulnar; and the Median. They supply the superior 

 extremity, including the shoulder and the axilla, 



1. The Nervus Scapular is is a small branch coming common- 

 ly from the upper part of the plexus, as formed by the fourth 

 cervical nerve. It goes backwards in company with the arte- 

 ria dorsalis superior scapulae, through the notch or foramen of 

 the upper costa of the scapula; and having thus got to the pos- 

 terior face of the latter, it gives filaments to the supra spinatus 

 muscle; continuing its course then on the posterior face of the 

 cervix scapulae, it is lost in filaments upon the infra-spinatus and 

 teres minor muscles. 



2. The Nervi Subscapulares of Bichat present some varieties 

 in their origin^ occasionally they come from the same trunk, 

 but commonly each one has its peculiar root from the central 

 parts of the axillary plexus. There are generally three of them. 

 One of them descends behind the axillary vessels, between the 

 subscapularis and the serratus major anticus; it crosses the teres 

 major, and is lost upon the contiguous part of the latissimus 

 dorsi. Another is distributed upon the subscapularis muscle. 

 The third descends along the anterior margin of the subscapu- 

 kris for a short distance, and distributes filaments to it, to the 

 tores minor and major muscles. 



3. The Nervi Thoracici are primarily two or three in num- 

 ber, and proceed from about the middle of the plexus. The 

 fasciculi into which they are resolved, may be distinguished as 

 anterior and posterior. The former are distributed, by filaments, 

 to the subclavian muscles, to the pectoralis minor and major, 

 and to the integu-ments covering the latter. The posterior thora- 



