108 ANATOMY FOR NURSES. [CHAP. IX. 



The right and left azygos veins connected with the inferior vena cava 

 below, and superior vena cava above, form a supplementary channel. 



The veins from stomach, spleen, pancreas, and intestines unite to form 

 the portal vein, which breaks up into capillaries in the liver, and is returned 

 to the inferior vena cava by the hepatic veins. 



