DISTRIBUTION OF THE VEINS. 125 



the humeral vein, and anastomoses with other veins of the 

 arm. 



The radial veins, two in number, arise from the junction 

 of the metacarpal veins above the knee ; they take the course 

 of the radial artery, and receive anastomosing vessels as they 

 ascend from the ulnar and superficial veins. 



The ulnar veins (with one exception) end in the common 

 trunk of the humeral vein. 



The humeral vein accompanies the artery ; it receives small 

 veins from the muscles. 



The axillary vein is the continuation of the humeral, aug- 

 mented by the accession of the triceps vein. Its branches 

 are, the subscapular vein, and dorsalis scapular ; the latter 

 terminates about midway between the chest and shoulder. 

 The remaining branches of -this vein are the humeral thora- 

 cic, and the external thoracic ; it also receives other small 

 veins, which contribute more or less to its volume. 



The pectoral vein runs the course of the pectoral artery. 

 It originates in branches from the abdominal parietes, con- 

 tinues to receive accessory vessels in its course, and ascends 

 along the inner and lower border of the first rib. 



The dorso-cervical vein consists of two divisions, ramify- 

 ing with the. dorsal and posterior cervical arteries ; it receives 

 the anterior intercostal vein. 



The inferior cervical vein runs down the lower part of 

 the neck in company with the artery ; the principal branches 

 are muscular, though some come from the skin and absorbent 

 glands in the vicinity. 



The vena azygos ends just as the trunk opens into the 

 auricle ; it returns the blood from the lower intercostal veins. 



THE POSTERIOR VENA CAVA. 



This is the corresponding venous trunk to the posterior 

 aorta, returning the blood from the parietes of the abdomen 

 and pelvis, the urinary and genital organs, and the posterior 

 extremities. It takes its course under the bodies of the lum- 

 bar vertebra?, runs along the great fissure of the liver, perfo- 



