THE DIGESTIVE SYSTEM 293 



The liver is surrounded b}- a connective-tissue capsule, the capsule 

 ojGlisson. At the Jiilum this capsule extends deep into the substance 

 of the liver, giving off broad connective-tissue septa, which divide the 

 organ into lobes. From the capsule and from these interlobar septa, 

 trabeculae pass into the lobes, subdividing them into lobules. In some 

 animals, as for example the pig, each lobule is completely invested by 

 connective tissue (Fig. 194). In man, only islands of connective 



B y H 



FiG.^ 195. — Section of Human Liver. X80. (Hendrickson.) P, Portal vein; H, 

 hepatic'artery; B, bile duct. P, H, B constitute the portal canal and.lie in the connec- 

 tive tissue between the lobules. 



tissue are found, usually at points where three or more lobules meet 

 (Fig. 195). The lobules are cylindrical or irregularly polyhedral in 

 shape, about i mm. in breadth and 2 mm. in length. Excepting 

 just beneath the capsule, where they are frequently arranged with 

 their apices toward the surface, the liver lobules have an irregular 

 arrangement. 



The lobule (Fig. 194) w^hich may be considered the anatomic unit 

 of structure of the liver, consists of secreting tubules arranged in a 



