BRANCHES OF THE PORTAL VEIN. 



501 



Tributaries. — The principal branches which by their union contri- 

 bute 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, l)ut more frequently 

 proceeds from its right branch. 



Fig. 319. — View op the Prin- Fig. 319. 



ciPAL Branches op the Vena 



P0RT.E. i 



1, lower surface of tlie right 

 lobe of the liver ; 2, stomach ; 3, 

 spleen ; 4, pancreas ; 5, duodenum ; 

 •3, ascending colon ; 7, small intes- 

 tines ; 8, descending colon ; a, vena 

 porta} dividing in the transverse 

 fissure of the liver ; h, splenic vein ; 

 c, right gastro-epiploic ; d, inferior 

 mesenteric ; e, superior mesenteric 

 vein ; /, superior mesenteric ar- 

 tery. 



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 py- 

 loric end of the stomach 

 along the small curvature. 

 On reaching the latter point 

 it turns downwards, and 

 opens into the trunk of the 

 vena portre. 



Tiie splenic vein, a vessel 

 of very considerable size, 

 returns the blood not only 

 from the spleen, but also 

 from the pancreas, the duo- 

 denum, 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 separately from the fissure of the spleen, and soon join to 

 form a single vessel. It is directed from left to right beneath the 

 pancreas, in company with the splenic arterj-, below which it is placed. 

 On reaching the front of the spine it joins the superior mesenteric 

 vein, nearly at a right angle. It receives gasiric branches (vasa brevia) 

 from the left extremity of the stomach, the left gasiro-epiplok vein, some 

 pancreatic and (Imdenal branches, and also the inferior mesenteric vein. 



The superior mesenteric vein lies to the right side, and some- 

 what in front of the artery of the same name. The distribution of its 

 branches corresponds with that of the superior mesenteric artery, and 

 it returns the blood from the several parts supplied by that vessel, viz., 

 from the small intestine, and from the ascending and transverse parts of 

 the colon. The trunk, formed by the union of its several branches, 

 inclines upwards and to the right side, passing in front of the duodenum 



