THE DIGESTIVE TRACT. 



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FIG. 218. 



Section of human liver, showing general arrangement of lobules : a, interlobular (portal) vein ; b, 

 intralobular (hepatic) vein; c, hepatic artery; d, bile-duct; the boundaries of the lobules are imper- 

 fectly defined by the irregular areas representing the poorly-developed capsule of Glisson. 



sideration of the vascular supply is necessary to an understanding of 

 the structure of the lobule. 



The interlobular vessels, situated 

 between the lobules at their periphery, 

 are continuations of those passing 

 through the transverse fissure ; they 

 are the portal vein, the hepatic ar- 

 tery, and the bile-duct. 



The portal vein, the largest of 

 the interlobular vessels, gives off nu- 

 merous branches, which enter the 

 lobule at the periphery and break up 

 into twigs, forming a rich, freely anas- 

 tomosing intralobular capillary 

 net-work. The meshes of this net- 

 work are somewhat elongated and 

 trapezoidal in form, the smaller end 

 of the spaces being directed towards 

 the centre of the lobule, an arrange- 

 ment produced by the convergence of 

 the capillary net-work to the centrally 

 placed intralobular vein, a branch 

 of the hepatic. 



The meshes of this lobular capil- 

 lary net-work are occupied by the 



Diagram of the structure of the liver: 

 />. V., the portal or interlobular vein, 

 which breaks up into the capillary net- work 

 of the lobule; H. V., central intralobular 

 vein, a branch of the hepatic; H. A., he- 

 patic artery, supplying nutrition to the in- 

 terlobular structures and terminating in the 

 lobular capillary net- work ; B.D., the inter- 

 lobular bile-duct which takes up the bile- 

 capillaries at the periphery of the lobule. 



