THE LIVER 



ISI 



vein, enter at the liiluni and divide into larji;e interl()l)ar branches 

 following the septa separating the lobes. The interlobar vessels 

 give off the interlobular branches which follow the septa between 

 the lobules. The interlobular branches of the portal veins give oft' 

 short branches ])assing to the surface of the lobules where they 

 break up into an intralobular capillary network. (Fig. 121.) The 

 hepatic artery follows the portal vein in its branching to the inter- 

 lol)ular se])ta, where its finer branches break u]) into capillary net- 



FiG. 121. — Diagram of a cross-section of a lobule of the liver of a mammal with 

 the hepatic cells radiating toward a common center. P, section of a branch of the 

 portal vein in the interlobular connective tissue; H, branches of the hepatic artery 

 near the branch of the portal vein; branches of this portal comp'onent extend to form 

 the capillary system of the lobule. Some twigs of the hepatic artery components 

 also join this capillary system. The diagram shows the capillaries forming a mesh- 

 work among the cords of liver cells. The capillaries converge toward the intralobular 

 vein (/L) in the center of the lobule. 



works, some of which supply the septa and then join the finer 

 branches of the hepatic vein, while others enter the lobules to join 

 with the intralobular capillary system. 



The intralobular capillary network is composed of wide lumened, 

 hepatic sinusoids. These anastomose irregularly along the free 

 surfaces of the cords of hepatic cells and everywhere separate the 

 cords from each other, so that each liver cell has several of these 

 sinusoids in contact with it, a disposition not found in the case of 

 other gland cells. The sinusoids carry the blood toward the center 

 of each lobule, where they empty it into the central vein which 

 emerges at the base of the lobule. Each central vein joins a sub- 



