328 



THE LIVEE 



transition to the very low columnar or flattened epithelium of 

 the interlobular bile duct. 



THE HEPATIC CELLS. These are large polyhedral cells which 

 possess one, or very frequently two, spherical nuclei and a coarsely 

 granular cytoplasm. A true cell membrane may be regarded as 

 being absent, yet there is often a sharply defined exoplasm which 

 forms the surface of the cell and simulates a true membrane. 



The nuclei of the hepatic cells are rich in chromatin, and stain 

 deeply. They are situated well within the cell, but usually in an 



eccentric position. Frequently 

 they contain a distinct nucleolus. 

 The cytoplasm of the hepatic 

 cell is finely reticular, the meshes 

 being filled with coarse granules 

 of irregular size. Many of these 

 are undoubtedly glycogenic gran- 

 ules, and show a decided reaction 

 when acted upon by Lugol's solu- 

 tion of iodin after alcoholic fixa- 

 tion. The amount of glycogen 

 present varies with the diet. 

 After digestion and absorption of 

 a carbohydrate meal it is greatly 

 increased, but disappears during 



fasting. Even when glycogen is quite deficient, the hepatic cells 

 still present a granular appearance from the presence of other 

 substances, possibly zymogens. 



Fat globules occur in the hepatic cells in limited numbers, and 

 appear to be a normal constituent. The globules vary much in 

 size, but are all very small. Their number is also dependent upon 

 diet and digestion. During absorption of a fatty meal, fat globules 

 occur in considerable numbers, and are most numerous in those 

 hepatic cells which are at the periphery of the lobule. They are 

 not normally found in the vicinity of the central vein. 



The hepatic cells also frequently contain brown or yellowish- 

 brown granules of ferruginous pigment, which are more prone to 

 occur in the interior of the lobule near the central vein. When 

 present in considerable amount this pigment can no longer be 

 considered a normal constituent of the hepatic cell. 



THE PORTAL CANALS. The portal canals are formed by 

 the ramifications of the portal vein, hepatic artery, and hepatic 



FIG. 272. TYPES OF CELLS FROM A SEC- 

 TION OF THE NORMAL HUMAN LIVER. 



A, the usual type of liver cell; B, 

 fatty, and C, pigmented cells. Types B 

 and C were very scarce. Hematein and 

 eosin. x 900. 



