390 



THE LIYER, 



corresponding branches of the hepatic artery to be immediately 

 described. 

 The hepatic artery terminates in three sets of branches, termed vaginal. 



Fig. 278. 



Fig. 278. — Cross Section of a Lobule of the Human Liver, in which the Capillary 

 Network between the Portal and Hei'Atic Veins has been fully injected 

 (from Sappey). 60 Diameters. 



1, section of the intralobular or conti-fil vein ; 2, its smaller branches collecting blood 

 from the capillary network ; 3, interlobular or peripheric branches of the vena portte 

 with their smaller ramifications passing inwards towards the capillary network in the 

 substance of the lobule. 



capsular, and interlobular. The vaf/inalhrancheB ramify within the portal 

 canals, supplying the walls of the ducts and vessels, and Glisson's capsule. 

 The capsular branches a^jpear on the surface of the liver spread out on 

 the fibrous coat, accompanied by their veins. The inierlohular branches 

 accompany the interlobular veins, but are much smaller : they transmit 

 blood directly to a part of the capillary network of the lobules inter- 

 mediate between the portal and hepatic veins. 



The capillary ncticorh of the lobules is very close, so that commonly 

 the interval between two vessels is not greater than the diameter of 

 one or two liver cells ffig. 279, 280). Moreover the vessels composing 

 it are comparatively large (ii--nT)th of an inch), and in specimens in 

 which it has been filled with transparent injection, can be seen, not 

 only to pass in a radiating manner, as before described, between 

 the intra- and interlobular veins, but also in the human subject to be 

 continued from one lobule to another. 



The distribution of the portal and hepatic veins within the lobules, as just 

 described, has suggested an explanation of the mottled aspect of the liver, an 

 appearance vs'hich formerly led to the erroneous idea of there being two sub- 

 stances in each lobule, one darker than the other. The colour of the hepatic 

 substance itself is pale yellow, and would be uniform throughout, were it not 

 varied according to the quantity of blood contained in its different vessels. Thus, 

 if the system of hepatic veins be congested, the centre of each lobule is dark, 

 and its margin pale ; this is the common case after death, and was named by 



