118 NORMAL HISTOLOGY. 



CHAPTEE XVI. 

 THE LIVER. 



The liver is derived from the epiderm and mesoderm. It is de- 

 veloped as a compound tubular gland, but afterwards loses that type. 

 Its functions are secretion and excretion. 



OUTLINE OF THE LIVER. 



Investment. 



Lobes. f Capsule of Glisson. 



Intralobular vein. 

 Interlobular veins, arteries, and 



Lobules { bile ducts. 



Hepatic cells. 

 Bile capillaries. 

 ^ Blood capillaries. 



f Mucous membrane. 



Gall cyst <{ Muscular coat. 



[_ Fibrous coat. 



The liver is invested with a capsule of fibrous connective tissue, 

 which sends prolongations into the substance of the organ, produ- 

 cing a framework for the support of the vessels and cells. The or- 

 gan is composed of lobes, and these are subdivided into lobules. 

 Each lobule is surrounded by a sheath of connective tissue, called 

 the capsule of Glisson. This capsule contains the interlobular veins 

 (branches of the portal vein), which send capillaries into the sub- 

 stance of the lobule. These converge in the center of the lobule and 

 form the intralobular vein, and this unites with others to form sub- 

 lobular veins, and these, in turn, form the hepatic vein, which con- 

 veys the blood from the liver. Between the capillaries are to be 

 found the hepatic cells, devoid of cell membranes and containing 

 granular protoplasm and one or two nuclei. The bile-capillaries 

 are between the liver cells and distinct from the blood-capillaries. 

 They are continuous with the interlobular bile-ducts, the latter form- 

 ing larger ducts which are lined with columnar epithelium. The 

 lobule also contains a small amount of areolar tissue. In the cap- 



