THE LIVER. 



293 



lobular connective tissue the portal vein and its branches are accom- 

 panied by divisions of the hepatic artery and bile passages. In a 

 transverse section of the liver the arrangement of these structures 

 in the interlobular tissue is such that the cross-sections of the vessels 

 belonging to the hepatic vein are seen to be at some distance from 

 the closely approximated branches of the portal vein and bile pas- 

 sages. Branches of the portal vein encircle the liver lobules at 

 different points, and while they remain within the interlobular con- 

 nective tissue, are known as interlobular veins. From these, small 

 offshoots are given off to the lobules which, on entering, divide into 

 capillaries and form a closely reticulated network between the 

 hepatic cords. The meshes of this network are about as large 

 as an hepatic cell, each cell coming in repeated contact with the 

 blood- capillaries. All of these capillarielL_pass toward the central 

 or intralobular vein of the lobule, which during its efferent passage 

 through the lobule continues to receive capillaries from the portal 



Blood capillaries. 



Intralobular vein. 



Cord of hepatic 

 cells. 



Interlobular vessel. 



Fig. 233. Injected blood-vessels in liver lobule of rabbit ; X Ioa 



system. The intralobular veins unite to form the sublobular veins, 

 situated in the interlobular connective tissue, and these unite to form 

 the larger hepatic veins which empty into the inferior vena cava. 

 The hepatic artery is of much smaller size than the portal vein. It 

 is distributed in the main to the connective tissue of the liver and 

 to the bile-ducts, breaking up into branches which are situated 

 in the interlobular connective tissue. The terminal capillaries 

 form small venules which communicate with the interlobular 



