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HAND-BOOK OF PHYSIOLOGY. 



The bile-capillaries commence between the hepatic cells, and are 

 bounded by a delicate membranous wall of their own. They appear to 

 be always bounded by hepatic cells on all sides, and are thus separated 



from the nearest blood-capillary by at least the 

 breadth of one cell (Figs. 203 and 204). 



The Gall-Bladder. The Gall-bladder (G, 

 B, Fig. 196) is a pyriform bag, attached to the 

 under surface of the liver, and supported also 

 by the peritoneum, which passes below it. The 

 larger end or fundus, projects beyond the 

 front margin of the liver; while the smaller end 

 contracts into the cystic duct. 



Structure. The walls of the gall-bladder 

 are constructed of three principal coats. (1) 

 Externally (excepting that part which is in 

 contact with the liver), is the serous coat, 

 which has the same structure as the peritoneum 

 with which it is continuous. Within this is 

 (2) the fibrous or areolar coat, constructed of 

 tough fibrous and elastic tissue, with which is 

 mingled a considerable number of plain muscu- 

 lar fibres, both longitudinal and circular. (3) Internally the gall-bladder 

 is lined by mucous membrane, and a layer of columnar epithelium. The 

 surface of the mucous membrane presents to the naked eye a minutely 

 honeycombed appearance from a number of tiny polygonal depressions 

 with intervening ridges, by which its surface is mapped out. In the cystic 



FIG. 203. Portion of a lobule of 

 liver, a, bile capillaries between 

 liver-cells, the network in which 

 is well seen; 6, blood capillaries. 

 X 350. (Klein and Noble Smith.) 



FIG. 204. Hepatic cells and bile capillaries, from the liver of a child three months old. Both fig- 

 ures represent fragments of a section carried through the periphery of a lobule. The red corpuscles 

 of the blood are recognized by their circular contour; vp, corresponds to an interlobular vein in im- 

 mediate proximity with which are the epithelial cells of the biliary ducts, to which, at the lower part 

 of the figures, the much larger hepatic cells suddenly succeed. (E. Bering.) 



duct the mucous membrane is raised up in the form of crescentic folds, 

 which together appear like a spiral valve, and which minister to the 

 function of the gall-bladder in retaining the bile during the intervals of 

 digestion. 



