350 



VENA PORT^E. 



constitute by their junction a large trunk, which ascends by the side of the 

 corresponding artery, crosses the transverse duodenum, and unites behind 

 the pancreas with the splenic in the formation of the portal vein. 



The Splenic vein commences in the structure of the spleen, and quits 

 that organ by several large veins : it is larger than the splenic artery, and 



Fig. 166. 



perfectly straight in its course. It passes horizontally inwards behind the 

 pancreas, and terminates near its greater end by uniting with the superior 

 mesenteric, and forming the portal vein. It receives in its course the 

 gastric and pancreatic veins, and near its termination the inferior mesen- 

 teric vein. 



The Gastric veins correspond with the gastric, gastro-epiploic, and 

 vasa brevia arteries, and terminate in the splenic vein. 



The VENA PORT^:, formed by the union of the splenic and superior 

 mesenteric vein behind the pancreas, ascends through the right border of 

 the lesser omentum to the transverse fissure of the liver, where it divides 

 into two branches, one for each lateral lobe. In the right border of the 

 lesser omentum it is situated behind and between the hepatic artery and 

 ductus communis choledochus, and is surrounded by the hepatic plexus 

 of nerves and lymphatics. At the transverse fissure each primary branch 

 divides into numerous secondary branches, which ramify through the 



* The portal vein. 1. The inferior mesenteric vein ; it is traced by means of dotted 

 4 ines behind the pancreas (2) to terminate in the splenic vein (3). 4. The spleen. 5. 

 Gastric veins, opening into the splenic vein. - 6. The superior mesenteric vein. . 7. The 

 descending portion of the duodenum. 8. Its transverse portion, which is crossed by the 

 superior mesenteric vein and by a part of the trunk of the superior mesenteric artery. 

 9 The portal vein. 10. The hepatic artery. 11. The ductus communis choledochus. 

 12. The division of the duct and vessels at the transverse fissure of the liver. 13. The 

 eystic duct leading to the gall bladder. 



