STRUCTURE OF THE LIVER. 



3 2 5 



union, form the main branches of the hepatic vein, which 



Fig. 86.* 



Lobule 



leaves the posterior border of 

 the liver to end by two or 

 three principal trunks in the 

 inferior vena cava, just before 

 its passage through the dia- 

 phragm. The swJ-lobular and 

 hepatic veins, unlike the portal 

 vein and its companions, have 

 little or no areolar tissue 

 around them, and their coats 

 being very thin, they form 

 little more than mere chan- 

 nels in the liver substance 

 which closely surrounds them. 



The manner in which the lobules are connected with 

 the sublobular veins by means of the small intralobular veins 

 is well seen in the diagram fig. 86, and in fig. 85, which 

 represent the parts as seen in a longitudinal section. The 

 appearance has been likened to a twig having leaves with- 

 out footstalks the lobules representing the leaves, and 

 the mllolular vein the small branch from which it springs. 

 On a transverse section, the appearance of the intra- 

 lolular veins is that of i, fig. 84, while both a transverse 

 and longitudinal section highly magnified are exhibited in 

 fig. 87. 



The hepatic artery, the function of which is to distribute 

 blood for nutrition to Grlisson's capsule, the walls of the 

 ducts and blood-vessels, and other parts of the liver, is 

 distributed in a very similar manner to the portal vein, its 

 blood being returned by small branches either into the 

 ramifications of the portal vein, or into the capillary plexus 

 of the lobules which connects the inter- and 

 veins. 



* Fig. 86. Diagram showing the manner in which the lobules of the 

 liver rest on the sublobular veins (after Kiernan). 



