756 THE VASCULAR SYSTEMS 



single vessel, which passes from left to right, grooving the upper and back part of 

 the pancreas below the artery, and terminates at its greater end by uniting at a 

 right angle with the superior mesenteric to form the portal vein. The splenic 

 vjein is of large size, and not tortuous like the artery. 



Tributaries. The splenic vein receives the vasa brevia from the left extremity 

 of the stomach, the left gastroepiploic vein, the pancreatic veins, and the inferior 

 mesenteric vein. 



(a) The short gastric veins (vv. gastricae breves), some four or five in number, 

 drain the fundus and left part of the greater curvature of the stomach, and pass 

 between the two layers of the gastrosplenic omentum to terminate in the splenic 

 vein or in one of its large tributaries. 



(6) The left gastroepiploic vein (v. gastroepiploica sinistra) receives tributaries 

 from the anterior and posterior surfaces of the stomach and from the great omen- 

 tum; it runs from right to left along the greater curvature of the stomach and ends 

 in the commencement of the splenic vein. 



(c) The pancreatic veins (vv. pancreaticae) consist of several small vessels which 

 drain the body and tail of the pancreas, and open into the trunk of the splenic 

 vein. 



(d) The inferior mesenteric vein (v. mesenterica inferior} returns blood from 

 the rectum, and the pelvic, iliac, and descending parts of the colon. It begins in 

 the rectum as the superior hemorrhoidal vein (v. haemorrhoidalis superior), which 

 has its origin in the hemorrhoidal plexus, and through this plexus communicates 

 with the middle and inferior hemorrhoidal veins. The superior hemorrhoidal 

 vein leaves the pelvis and crosses the iliac vessels in company with the superior 

 hemorrhoidal artery, and is continued upward as the inferior mesenteric vein. 

 This vein lies to the left of the inferior mesenteric artery, and ascends behind the 

 peritoneum and in front of the left Psoas; it then passes behind the body of the 

 pancreas and opens into the splenic vein; sometimes it terminates in the angle of 

 union of the splenic and superior mesenteric veins. 



Tributaries. The inferior mesenteric vein receives the sigmoid veins (vv. sig- 

 moideae) from the sigmoid flexure and the left colic vein (v. colica sinistra) trom 

 the descending colon and splenic flexure. 



The superior mesenteric vein (v. mesenterica superior) returns the blood from 

 the small intestine, and from the cecum and ascending and transverse portions 

 of the colon. It begins in the right iliac fossa by the union of the veins which 

 drain the terminal part of the ileum, the cecum, and vermiform appendix, and 

 ascends between the two layers of the mesentery on the right side of the supe- 

 rior mesenteric artery. In its upward course it passes in front of the right 

 ureter, the inferior vena cava, the third part of the duodenum, and the uncinate 

 process of the head of the pancreas. Behind the neck of the pancreas it unites 

 with the splenic vein to form the portal vein. 



Tributaries. Besides the tributaries which correspond with the branches of 

 the superior mesenteric artery viz., the veins of the small intestine (vv. intesti- 

 nales), the ileocolic (v. ileocolica), the right colic (vv. colica dextrae), and the middle 

 colic (v. colica media), the superior mesenteric vein is joined by the right gastro- 

 epiploic and pancreaticoduodenal veins. 



The right gastroepiploic vein (v. gastroepiploica dextrd) receives tributaries from 

 the great omentum and from the lower parts of the anterior and posterior surfaces 

 of the stomach ; it runs from left to right along the greater curvature of the stomach ; 

 between the two layers of the great omentum. 



The pancreaticoduodenal veins (vv. pancreaticoduodenales) accompany their cor- 

 responding arteries; the lower of the two frequently joins the right gastroepiploic 

 vein. 



The gastric vein (v. coronaria ventricidi) derives tributaries from both surfaces 



