

UPPER EXTREMITY AND THORAX, ANTERIOR. 275 



ber. They are grouped in several sets, two of which are 

 especially worthy of notice. (i) The pectoral set: four 

 or five in number, below the lower border of the pectoralis 

 major and with the long thoracic artery. These receive 

 the drainage from the front and side of the chest (including 

 the mammary gland) ; hence in inflammatory or malignant 

 disease of the chest or mamma these lymphatics are first 

 affected. (2) The axillary set : three or four, located along 

 the axillary vein. These receive the lymph from the upper 

 extremity and from the pectoral set of glands. They be- 

 come enlarged in inflammatory affections of the extremity, 

 or from the chest by extension through the first set. They 

 are closely connected to the vein, especially in the inflamed 

 condition. Their removal should proceed with caution. 



The Axillary Vein. 



The axillary vein is formed by the confluence of the 

 venae comites of the brachial artery and the basilic vein, 

 at the lower border of the subscapularis muscle. It takes 

 a course upward along the inner side and front of the artery 

 (overlapping it in front), to become the subclavian vein at 

 the lower border of the first rib. It receives, besides the 

 veins which unite to form it, the veins corresponding to the 

 branches of the axillary artery, and the cephalic vein, 

 which passes through the costocoracoid membrane to 

 empty into it. 



The Axillary Artery. Figs. 62, 63. 



This is the continuation of the subclavian, from the 

 lower border of the first rib to the lower border of the teres 

 major muscle. It lies near the outer angle of the axillary 

 space. It is divided into three portions by the pectoralis 

 minor, that above, behind, and below the muscle. 



The Relations of the Axillary Artery. The axillary 



