DISSECTION OF THE ABDOJIEN. 



331 



fissure it furnishes a sheath that accompanies the poi-tal vein, hepatic 

 artery, and bile duct into the liA'er. This sheath is the capsule 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 wdth blood 

 by two vessels. The first and 



much the larger of the two is the longitudinal section of a Portal Canal, 



Tinrtnl vpin tlip nthpr i« flip Vipn- containing a Portal Vein, Hepatic Artery, 



portal \eni, tne Otnei is ine nep- aj,d Hepatic Duct, from the Pig (after 



atic arterv Kleman). about 5 diameters. 



mi T. 17 11 X -i. P- Branch of vena portiB, situated in a portal 



ihe rORTAL VEIN collects its canal, formed amongst the hepatic lobules of the 



blood from thestomach, intestines, ^ZlJL^'c^:^ iT^a'i^^I^!^^ f^ 

 spleen, and pancreas. Entering ^Z.'^f^ J'^r^nl^K^rir^l^ 



the liver at the portal fissure, this ;j;;^^f' ^ ^"^"'^ '* • "■ ^epatio artery ; ,/. Biliary 



vein comports itself like an ar tery, 



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

 ■come 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 

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

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

 \.f each lobule, they form an interlobular jilexiis. From this plexus 

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

 lobular 'plexm. 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 — 



