480 



POETAL VEIN. 



passes upwards and a little to the right to reach the transverse fissure of the 

 liver. It is placed close behind the hepatic artery and the bile-duct : and 



Fig. 326. Fig. 326. VIEW OP THE PRIN- 



CIPAL BRANCHES OF THE VENA 

 PORT^J. i 



1, lower surface of the right 

 lobe of the liver ; 2, stomach ; 3, 

 spleen ; 4, pancreas ; 5, duodenum ; 

 6, ascending colon ; 7, small intes- 

 tines ; 8, descending colon ; 8, vena 

 portse dividing in the transverse 

 fissure of the liver ; 6, splenic vein ; 

 c, right gastro-epiploic. ; d, inferior 

 mesenteric ; e, superior mesenteric 

 vein ; /, superior mesenteric ar- 

 tery. 



is surrounded by the fila- 

 ments of the hepatic plexus 

 of nerves, together with nu- 

 merous lymphatics. All these 

 are imbedded in loose con- 

 nective tissue, and enclosed 

 within the layers of the small 

 omentum. Within the trans- 

 verse fissure it is somewhat 

 enlarged, and is there named 

 sinus of the portal vein. 



Near the right end of the 

 transverse fissure, the vena 

 portse divides into two 

 branches. That of the right 

 side enters directly the sub- 

 stance of the corresponding 



lobe of the liver, and spreads out into branches, each of which is accom- 

 panied by an offset of the hepatic artery and of the hepatic duct. The 

 left branch, which is smaller, but necessarily longer, passes across to gain 

 the left end of the transverse fissure, where it enters the liver and ramifies 

 like the preceding branch. 



TRIBUTARIES. The principal branches which by their union contribute to 

 form the vena portse are the coronary vein of the stomach, the superior 

 mesenteric, and the splenic veins. The cystic vein is also sometimes a 

 lateral tributary of the portal vein, but more frequently proceeds from its 

 right branch. 



The coronary vein of the stomach lies parallel with the artery of the same 

 name. Its size is inconsiderable, and its direction transverse from the 

 cardiac to the pyloric end of the stomach along the small curvature. On 

 reaching the latter point it turns downwards, and opens into the trunk of 

 the vena portse. 



The SPLENIC VEIN, a vessel of very considerable size, returns the blood 

 not only from the spleen, but also from the pancreas, the duodenum, the 

 greater part of the stomach and omentum, the descending colon, and part 

 of the rectum. It commences by five or six branches, which issue sepa- 



