VEINS OF THE UPPER EXTREMITY. 



887 



The Axillary Vein. 



The axillary vein (v. 

 axillaris) (Fig. 762) is 

 formed by the union of 

 the two brachial veins, 

 usually at about the lower 

 border of the pectoralis 

 major. It lies along the 

 inner side of the axillary 

 artery, and at the lower 

 border of the first rib 

 passes directly into the 

 subclavian vein. In the 

 lower part of its course it is 

 separated from the artery 

 by the ulnar nerve and the 

 inner head of the median ; 

 above, it is more nearly in 

 contact with it. 



The axillary vein 

 possesses a pair of valves, 

 usually situated at the 

 level of the lower border of 

 the subscapularis muscle. 

 Its walls are intimately 

 connected with the fascia 

 of the axillary space, so 

 that, as in the case of the 

 subclavian, its lumen 

 remains patent even when 

 empty of blood, and con- 

 sequently air may possibly 

 enter in cases where the 

 vein is wounded. 



Tributaries . — 

 These correspond in 

 general with the branches 

 of the artery, except that 

 the axillary vein receives 

 the cephalic, which is un- 

 represented by an artery, 

 and, furthermore, the 

 acromial thoracic, which 

 corresponds to the artery 

 of the same name, instead 

 of opening into the axil- 

 lary, connects with the 

 cephalic. Of especial 

 importance among the 

 tributaries is the long 

 thoracic vein (v. thorac- 

 alis lateralis) which brings 

 to the axillary the blood 

 from the lateral walls of 

 the thorax. Its branches 

 of origin are the vense 

 comites of the branches of 



Fig. 762. 



Pectoralis major 



Costo-coracoid 



ligament' 



Deltoid 

 Axillary vein 



Anterior circumflex 

 vein 



Cephalic vein 

 Pectoralis major, 



Cotaco-brachialis 



Biceps- 



Median cephalic vein. 

 Cephalic vein 



Median vei 



Inner vena conies of 

 radial artery, 



Pectoralis minor 



-Subscapular veio 



'Teres major 

 Posterior circumflex vein 

 .\'enae comites of brachial a: tery 



Common superficial ulnar 

 Median basilic vein, 



Accessory median vein 



Superficial veins oi anterior surface of right forearm and 

 axillary vein and its tributaries. 



the thoracic arteries, and they return the blood from the 



