CH. XXXIII. 



STRUCTURE OF THE LIVER 



503 



Fio. 402. A. Liver-cells. B. Ditto, contain- 

 ing various-sized particles of fat. 



the whole surface of the organ. It is thickest where the peritoneum 

 is absent, and is continuous on the general surface of the liver with 

 the fine and, in the human subject, almost imperceptible areolar tissue 

 investing the lobules. At the trans- 

 verse fissure it is merged in the 

 areolar investment called Glisson's 

 capsule, which, surrounding the 

 portal vein, hepatic artery and 

 hepatic duct, accompanies them in 

 their branchings through the sub- 

 stance of the liver. 



Structure. The liver is in origin 

 a tubular gland, but as development 



progresses it soon loses all resemblance to the tubular glands found 

 elsewhere. It is made up of small roundish or oval portions called 

 lobules, each of which is about oV of an inch (about 1 mm.) in dia- 

 meter, and composed of the liver cells, between which the blood- 

 vessels and bile-vessels ramify. 

 The hepatic cells (fig. 406), 

 which form the glandular or 

 secreting part of the liver, are 

 of a spheroidal form, somewhat 

 polygonal from mutual pres- 

 sure, about sfo- to y^Vs- inch 

 (about -gV to T V mm.) in dia- 

 meter, possessing a nucleus, 

 sometimes two. The cell-sub- 

 stance, composed of protoplasm, 

 contains numerous fatty par- 

 ticles, as well as a variable 

 amount of glycogen. The cells 

 sometimes exhibit slow amoe- 

 boid movements. They are 

 held together by a very deli- 

 cate sus tentacular tissue, con- 

 tinuous with the inter-lobular 

 connective tissue. 



To understand the distri- 

 bution of the blood-vessels in 

 the liver, it will be well to 

 trace, first, the two blood- 

 vessels and the duct which enter the organ on the under surface at 

 the transverse fissure, viz., the portal vein, hepatic artery, and hepatic 

 duct. As before remarked, all three run in company, and their appear- 

 ance on longitudinal section is shown in fig. 403. Eunning together 



FIG. 403. Longitudinal section of a portal canal, con- 

 taining a portal vein, hepatic artery and hepatic 

 duct, from the pig. P, branch of vena portse, 

 situated in a portal canal amongst the lobules of 

 the liver; I, I, and giving off vaginal branches; 

 there are also seen within the large portal vein 

 numerous orifices of the smallest interlobular veins 

 arising directly from it ; o, hepatic artery ; d, bile 

 duct, x 5. (Kiernan.) 



