VENA PORTARUM. 269 



In this course, the splenic receives the small veins,* ( Venas 

 Breves,) corresponding with the vasa brevia of the great end of 

 the stomach, and then, successively, several branches from the 

 pancreas. It likewise receives the gastric, or the superior co- 

 ronary vein of the stomach, the right gastro-epiploic, ana the 

 left gastro-epiploic of the same viscus, all of which correspond 

 with the arteries distributed to the latter. 



b. The Inferior Mesenteric Vein (Vena Meseraica Inferior) 

 corresponds with the inferior mesenteric artery, and, conse- 

 quently, derives its primitive branches from the rectum by the 

 upper hemorrhoidal veins, which anastomose with the lower; 

 from the sigmoid flexure of the colon, and from the left de- 

 scending portion of the latter. The trunk formed by these 

 branches, ascends behind the peritoneum, between the left ureter 

 and the aorta; and going up behind the pancreas, is discharged 

 into the splenic vein an inch or two from its termination. But, 

 like the veins belonging to the lesser curvature, and the right 

 side of the stomach, it sometimes empties directly into the vena 

 portarum, or into the upper end of the superior mesenteric. 



c. The Superior Mesenteric Vein (Vena Meseraica Superior) 

 is the largest of the trunks which contribute to form the vena 

 portarum. It is derived from the ramifications of the superior 

 mesenteric artery upon the small intestines, the ileo-colic valve, 

 the right ascending and the transverse colon. Its branches 

 constitute in the mesentery and the mesocolon a vascular in- 

 tertexture, forming arches and meshes adhering to the corre- 

 sponding ones of the arteries. In the transverse mesocolon, it, 

 like the artery, anastomoses with the inferior mesenteric vein. 

 Its trunk being formed by the union of these several branches, 

 ascends the mesentery, and goes in front of the duodenum, 

 where the latter crosses the spine; immediately afterwards it 

 gets behind the pancreas, and near its right end is joined by the 

 splenic vein. It here, also, receives small branches from the 

 duodenum, from the pylorus, and from the gall-bladder. 



The trunk of the Vena Portarum being formed behind the 



* M, Bauer discovered, in 1824, valves in these vessels, contrary to the gene- 

 ral analogy of the system of the Vena Pcrtaruin. His observations have been 

 confirmed by H. Cloquet. 



24* 



