The splenic vein is a deoxygenated blood vessel which drains the spleen, pancreas, stomach, and greater omentum. It is formed in the hilum of the spleen by the confluence of several smaller branches that come out of this organ. Then it receives blood from the left gastroepiploic vein, which drains part of the stomach, as well as from the pancreatic, the inferior mesenteric and the short gastric vein.
The splenic vein joins the superior mesenteric to form the hepatic portal vein, which together make up the portal system of veins. The portal system does not empty its content into the vena cava; it carries the deoxygenated blood into the liver instead. However, this blood is rich in nutrients, like amino acids, fatty acids, vitamins, glucose, minerals etc, as they are the products of digestion. These nutrients are processed and metabolized in the liver.
Vessels draining into the splenic vein
Besides the above-described veins, which formed the portal system, the following vessels drain directly into splenic vein: the pancreatic, pancreaticoduodenal, prepyloric, gastroepiploic, and the left and right gastric veins, which in turn receive the veins of the pylorus.
Below, a drawing of the digestive system organs and the special veins that make up the portal system, which include the splenic vein.
