II 



EXTEENAL DIGESTIVE SECKETIONS 



133 



the bile into the duodenum during digestion, 7-10 cm. from the 

 pylorus. 



By a special system of distribution, capillary formation, and 

 reconstitution of these vessels, the hepatic parenchyma is divided 

 into a number of lobules or acini varying in diameter from 

 1 to 2 mm. polyhedral or spheroid in shape, which profoundly 

 modify the original tubular form of the gland. The branches of the 



FIG. 48. Section of liver lobule, with blood-vessels and bile-ducts injected. (Cadiat.) b, Z>, inter- 

 lobular veins ; a, intralobular vein ; c, interlobular bile-ducts, with, which the bile canaliculi 

 of the lobule are connected. The latter are only injected in the peripheral parts of the 

 lobule. 



portal vein and hepatic artery penetrate as the interlobular veins 

 and arteries between the lobules, sending twigs to the interior 

 of the lobule which soon form a dense capillary network, from 

 which the intralobular veins re-form, and lead into a central vein 

 (Fig. 48). The intralobular and central veins are the beginning 

 of the efferent hepatic veins, which traverse the lobule in a radial 

 direction, and unite in the sublobular veins ; these form into larger 

 and larger branches, converging towards the posterior surface of 

 the liver, where they open, as we said, into the inferior vena cava. 



