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IOLOGY 



The Hepatic Veins (vv. hepaticce) commence in the substance of the liver, in the 

 terminations of the portal vein and hepatic artery, and are arranged in two groups, 

 upper and lower. The upper group usually consists of three large veins, which 

 converge toward the posterior surface of .the liver, and open into the inferior 

 vena cava, w r hile that vessel is situated in the groove on the back part of the liver. 

 The veins of the lower group vary in number, and are of small size; they come 

 from the right and caudate lobes. The hepatic veins run singly, and are in direct 

 contact with the hepatic tissue. They are destitute of valves. 





FIG. 591. The portal vein and its tributaries. 



THE PORTAL SYSTEM OF VEINS (Fig. 591). 



The portal system includes all the veins which drain the blood from the abdominal 

 part of the digestive tube (with the exception of the lower part of the rectum) 

 and from the spleen, pancreas, and gall-bladder. From these viscera the blood 

 is conveyed to the liver by the portal vein. In the liver this vein ramifies like an 

 artery and ends in capillary-like vessels termed sinusoids, from which the blood is 



