THE HEART AND THE BLOOD VESSELS 



Jugular 



arm to form two trunks, which finally unite, forming 

 one large vessel, the superior vena cava; Fig. 81. This 

 empties directly into 

 the top of the right 

 auricle, as we have 

 already noticed. The 

 blood from the lower 

 part of the body 

 unites in large veins, 

 finally forming one 

 great trunk, the in- 

 ferior vena cava (Figs. 

 65 and 81), which 

 also empties into the 

 right auricle. By . 

 these two large veins 

 all of the blood car- 

 ried out from the left 

 ventricle, after pas- 

 sing through an im- 

 mense system of cap- 

 illaries, is brought 

 back to the right 

 ventricle to be sent 

 once more to the 

 lungs. In general, 

 one may say that the 

 blood vessels near the 

 surface of the body 

 are veins, while the arteries are imbedded deeply in the 

 tissue; hence the wounding of the flesh is almost sure to cut a 

 vein, but will not, unless very deep, injure an artery. 



As a rule the arteries and veins going to and from a given 

 area or organ lie closely parallel to one another, and often 

 have the same names, e. g. subclavian artery, subclavianvein. 



^Stomach 

 5pleen 



Kidney 



Intestine 



.\ \laUffac 



FIG. 81. DIAGRAM 



Showing the course of the chief veins. 



