580 



THE LIVER. 



cends in the lesser omenturn to the transverse fissure of the 

 liver, where it divides commonly into three branches, one 

 of which passes to the right lobe, another to the left, and 

 the third to the lohulus Spigelii. These branches follow 

 the ramifications of the vena portarum, and biliary ducts, 

 distributing upon each a complicated tissue of anastomosing 

 vessels, ultimately breaking into a plexus for each of the 

 acini. This artery is designed to nourish the liver. 



The vena port arum is very interesting from the curious 

 fact of its having an origin as a vein, but a termination 



like an artery. It is very large, 

 and is formed by a junction of 

 the splenic and mesenteric veins, 

 which receive the blood of the 

 stomach, intestines, spleen, and 

 pancreas, forming a tube from 

 three to five inches in length, 

 which is seen to commence be- 

 hind the pancreas, in front of 

 the aorta, and to ascend ob- 

 liquely upward over the duode- 

 num to the transverse fissure of 

 the liver, where it divides into 

 two branches, at right angles 

 with the vein, called the sinus 

 venaportarum. These branches 

 are right and left. The right is 

 the largest, but shortest, and radiates in minute branches 

 to the right lobe, while the left after the same manner is 

 distributed to the left lobe of the liver. 



This vein is accompanied by the hepatic artery. Both 

 proceed from the centre to the circumference of the liver, 

 and both are enclosed in canals termed portal canals, which 

 are formed of the sheaths or processes from the capsule 

 of Glisson. Injection shows that an anastomosis occurs 



FIG. 188 represents the Trunk of the Vena Porta with its roots and branches 

 in the intestines and liver, a a Veins from the intestines. 6 Trunk of vena 

 porta. c c Branches distributed in the liver. 



