682 ANGIOLOGY 



it then passes behind the body of the pancreas and opens into the lienal vein; 

 sometimes it ends in the angle of union of the lienal and superior mesenteric veins. 



Tributaries. The inferior mesenteric vein receives the sigmoid veins from the 

 sigmoid colon and iliac colon, and the left colic vein from the descending colon and 

 left colic flexure. 



The Superior Mesenteric Vein (v. mesenterica superior) returns the blood from the 

 small intestine, from the cecum, and from the 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 process, and ascends 

 between the two layers of the mesentery on the right side of the superior mes- 

 enteric artery. In its upward course it passes in front of the right ureter, the 

 inferior vena cava, the inferior part of the duodenum, and the lower portion of 

 the head of the pancreas. Behind the neck of the pancreas it unites with the lienal 

 vein to form the portal vein. 



Tributaries. Besides the tributaries which correspond with the branches of the 

 superior mesenteric artery, viz., the intestinal, ileocolic, right colic, and middle colic 

 veins, the superior mesenteric vein is joined by the right gastroepiploic and pan- 

 creaticoduodenal veins. 



The right gastroepiploic vein (v. gastroepiploica dextra) receives branches from the 

 greater omentum and from the lower parts of the antero-superior and postero- 

 inferior surfaces of the stomach; it runs from left to right along the greater curva- 

 ture of the stomach between the two layers of the greater omentum. 



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

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

 vein. 



The Coronary Vein (v. coronaria ventriculi; gastric vein) derives tributaries from 

 both surfaces of the stomach; it runs from right to left along the lesser curvature 

 of the stomach, between the two layers of the lesser omentum, to the esophageal 

 opening of the stomach, where it receives some esophageal veins. It then turns 

 backward and passes from left to right behind the omental bursa and ends in the 

 portal vein. 



The Pyloric Vein is of small size, and runs from left to right along the pyloric 

 portion of the lesser curvature of the stomach, between the two layers of the lesser 

 omentum, to end in the portal vein. 



The Cystic Vein (v. cystica) drains the blood from the gall-bladder, and, accom- 

 panying the cystic duct, usually ends in the right branch of the portal vein. 



Parumbilical Veins(OT. parumbilicales) . In the course of the ligamentum teres 

 of the liver and of the middle umbilical ligament, small veins (parumbilical) are 

 found which establish an anastomosis between the veins of the anterior abdominal 

 wall and the portal, hypogastric, and iliac veins. The best marked of these small 

 veins is one which commences at the umbilicus and runs backward and upward 

 in, or on the surface of, the ligamentum teres between the layers of the falciform 

 ligament to end in the left portal vein. 



Collateral venous circulation to relieve portal obstruction in the liver may be effected by 

 communications between (a) the gastric veins and the esophageal veins which often project 

 as a varicose bunch into the stomach, emptying themselves into the hemiazygos vein; (6) the 

 veins of the colon and duodenum and the left renal vein; (c) the accessory portal system of 

 Sappey, branches of which pass in the round and falciform ligaments (particularly the latter) 

 to unite with the epigastric and internal mammary veins, and through the diaphragmatic 

 veins with the azygos; a single large vein, shown to be a parumbilical vein, may pass from 

 the hilus of the liver by the round ligament to the umbilicus, producing there a bunch of 

 prominent varicose veins known as the caput medusa; (d) the veins of Retzius, which connect 

 the intestinal veins with the inferior vena cava and its retroperitoneal branches; (e) the inferior 

 mesenteric veins, and the hemorrhoidal veins that open into the hypogastrics; (/) very rarely 

 the ductus venosus remains patent, affording a direct connection between the portal vein and 

 the inferior vena cava. 



