DISSECTION OF THE ABDOMEN. 



331 



I 



fissure it furnishes a sheath that accompanies the portal vein, hepatic 

 artery, and bile duct into the liver. This sheath is the caps-ule of Glisson. 



Lobules of the Liver. — When a fresh-cut surface of the liver is examined, 

 it shows a system of lines mapping it out into areas about the size of a 

 pin's head. These areas are sec- 

 tions of the lobules of the liver, 

 which are united together by 

 interlobular connective - tissue. 

 This interlobular connective-tissue 

 is much more abundantly de- 

 veloped in the pig, and, conse- 

 quently, in that animal the lobu- 

 lation of the liver substance is 

 much more evident. A lobule 

 may be viewed as having a frame- 

 work of blood-vessels, in which are 

 set the liver-cells. Between the 

 adjacent cells the rootlets of the 

 bile passages begin, and there are 

 possibly also branches of nerves 

 and lymphatic vessels. 



The liver is supplied with blood 

 by two vessels. The first and 

 much the larger of the two is the longitudinal section of a portal canal, 



, , • j_i ii • J.I, 1, CONTAINING a Portal Vein, Hepatic Artery, 



portal vem, the other is the nep- ^j, hepatic dhct, trom the pig (after 



, . , Klevnan). About 5 diameters. 



atic artery. 



•^ n . -. ^- Branch of vena portse, situated in a portal 



The Portal Vein collects its canal, formed amongst the hepatic lobules of the 



, ^ • J. J.- liver ; p. p. Larger Ijranches of portal vein, giving 



blood from the stomach, intestines, off smaller ones (i. ;.), named interlobular veins; 



, J TTi 4.rt„*„™ there are also seen within the large portal vein 



spleen, and. pancreas. Jlintermg numerous orifices of interlobular veins arising 



the liver at the portal fissure, this ^™f ^ '"" "'= "■ '"'^"'" "*"'^= " ^'"''^ 

 vein comports itself like an ar tery, 



in that it reduces itself by division and subdivision to branches that 

 become progressively smaller until they terminate in a set of capillaries. 

 In their course through the liver, the larger branches of the vein run 

 in tunnels of the liver substance — the portal canals — which contain 

 also branches of the hepatic artery and bile ducts, and are lined by 

 Glisson's capsule. The smaller branches of the portal vein are distri- 

 buted in the interlobular connective-tissue, where, at the circumference 

 of each lobule, they form an interlobular plexus. From this plexus 

 capillary vessels penetrate the lobule, and form within it the intra- 

 lobular plexus. The capillaries of this last plexus converge towards 

 the axis of the lobule, and there empty themselves into what is termed 

 the central vein of the lobule. This is the initial vessel of the hepatic 

 system of veins, and at the base of the lobule it joins a larger vessel— 



