242 



THE LIVER. 



manner all the intralobular veins discharge, and the sublobular 

 veins unite to form larger veins, which terminate in the hepatic 

 veins, which, as three large trunks and some small ones, discharge 

 into the vena cava, at the back of the liver. 



Hepatic Duct. Between adjoining hepatic cells are small 

 passages, intercellular biliary passages or bile-canaliculi, which are 

 the beginnings of the hepatic duct (Fig. 137). It would be more 

 correct to say that the beginnings of the hepatic duct are within 

 the hepatic cells themselves, for it has been demonstrated that in 

 the interior of these cells are vacuoles which communicate with 

 the bile-canaliculi (Fig. 137). The canaliculi pass outward to the 

 interlobular spaces, where they form an interlobular biliary plexus, 

 from which ducts are given off that enter the portal canals, and, 

 covered with Glisson's capsule, in company with the branches of 



Intralobular 



Branch of 



portal vein. 

 Bile-duct. 



FIG. 136. Section through liver of pig, showing chains of liver-cells; x 70 (Bohm 



and Davidoff). 



the portal vein and hepatic artery, they emerge from the liver at the 

 transverse fissure as two trunks, right and left, which unite to 

 form the hepatic duct. This is from 3 to 5 cm. in length and. has 

 a diameter of about 4 mm. The bile-canaliculi have no wall 

 save such as is made by the hepatic cells. The interlobular ducts 

 have a wall of connective tissue lined with columnar epithelium. 

 In the larger duct is fibrous and plain muscular tissue. The 

 ducts in the portal canals have opening into them cecal diverticula, 

 which are regarded by Sappey as mucous glands. 



Gall-bladder. The gall-bladder lies on the under surface 

 of the liver in the fossa vesicalis, being attached thereto by vessels 

 and connective tissue. The neck of the gall-bladder terminates 

 in the cystic duct, which is spiral in form, and unites with the 



