870 



THE LIVER. 



with the delicate areolar tissue which lies between the small lobules of the 

 gland. At the transverse fissure it becomes continuous with the capsule of 

 Glisson, by which name is designated a sheath of areolar tissue which sur- 

 rounds the branches of the portal vein, hepatic artery, and hepatic duct, as 

 they ramify in the substance of the liver, and which becomes more delicate 

 as the vascular branches become smaller. 



Lobules. The proper substance of the liver, which has a reddish brown 

 colour and a mottled aspect, is compact, but not very firm. It is easily 

 cut or lacerated, and is not unfrequently ruptured during life from accidents 

 in which other parts of the body have escaped injury. When the substance 

 of the liver is torn, the broken surface is not smooth but coarsely granular, 

 the livtr being composed of a multitude of small lobules, which vary from 

 half a line to a line in diameter. 



These lobules are closely packed polyhedral masses, and in some animal s, 

 as in the pig, are completely isolated one from another by areolar tissue con- 

 tinuous with the fibrous coat of the liver and with the capsule of Glisson ; 

 but in the human subject, and in most animals, although they are very dis- 

 tinguishable on account of the disposition both of vessels and parenchyma, 

 they are not distinctly separated, but exhibit continuity through their 

 capillary networks and cellular constituents. Notwithstanding this, how- 

 ever, we may consider the lobules of the human liver as being marked out 

 by slight iuterlobular intervals. 



Fig. 607. 



Fig. 607. LONGITUDINAL SECTION 

 OF A PORTAL CANAL, CONTAINING 

 A PORTAL VEIN, HEPATIC 

 ARTERY, AND HEPATIC DUCT, 

 FROM THE PIG (after Kiernan). f 



p, branch of vena portse, situated 

 in c, c, a portal canal, formed 

 amongst the lobules of the liver 

 (, ') Pi Pt vaginal branches of 

 portal vein, giving off smaller ones 

 (i, i), named interlobular veins; 

 there are also seen within the large 

 portal vein numerous orifices of the 

 smallest interlobular veins arising 

 directly from it ; a, hepatic artery ; 

 d, hepatic duct. 



The lobules of the liver 

 have throughout its substance 

 in general the polyhedral form 

 of irregularly compressed sphe- 

 roids ; but on the surface they 

 are flattened and angular. 

 They are all compactly ar- 

 ranged round the sides of 



branches of the hepatic veins, each lobule resting by a smooth surface or 

 base, upon the vein, and being connected with it by a small venous trunk, 

 which arises in the centre of the lobule, and passes out from the middle of 

 its base to end in the larger subjacent vessel. The small veins proceeding 

 from the centre of the lobules are named the intralobular veins, and those 

 on which the lobules rest, the sublobular veins. If one of these sublobular 

 veins be opened, the bases of the lobules may be seen through the coats of 



