LIVER OF MAMMALIA. 



489 



Longitudinal section of a small portal vein and 

 canal, clvii". 



nified of a « sublobular venule,' fig. 371, shows the commonly 

 hexagonal outline of the flattened bases of the lobules 4, the ter- 

 minations of the ' intralobular ' venules 7, the interlobular fissures 



8, and the ' interlobular spaces ' 



9, at their angles : these are 

 continued into the intervals be- 

 tween the more or less rounded 

 lateral surfaces of the closely 

 packed lobules. The ramifica- 

 tion of the intralobular venule 

 5 is seen in the longitudinal 

 section of the lobules, l, 3. In 

 the Seal the intralobular veins 

 at their exit from the lobules 

 enter hepatic -venous canals, 

 where they unite into branches, 

 which are connected by a fine 

 cellular tissue, forming a sheath 

 round the hepatic veins. 1 



The portal vein, in Mam- 

 mals, fig. 372, is formed by the 

 superior, b, and inferior, c, mesenteric veins, by the splenic vein, 

 d, by the gastro-epiploic, e, and pancreatic, /, veins : the trunk, 

 a, entering the portal fissure, divides into a right, A, and left, g, 

 branch : these penetrate their 

 respective divisions of the liver, 

 ramify and subdivide therein, 

 along tracts termed ' portal ca- 

 nals,' fig. 373, «, a ; but which 

 likewise lodge branches of the 

 hepatic artery, g, and duct, h. 

 As all these are connected to- 

 gether by a prolongation of the 

 areolar tissue of ' Glisson's cap- 

 sule,' branches continued from 

 the portal vein, e, and forming a 

 plexus in that tissue, are termed 

 1 vaginal,' from which, as well as 

 directly from the portal vein, as 

 at/*, venules enter the interlobular spaces, are called c interlobular 

 venules,' fig. 374, a, a, penetrate the lobule, b, and form a capil- 

 lary plexus therein, most richly at the periphery, but from which 

 the ' intralobular vein,' c, begins. The hepatic artery has a similar 



1 clvii". p. 738. 



Lobules showing the portal venous plexus 



CLVII". 



