Pulmonary vein drain into the pulmonary circulation in whole or in part, this is known as a total anomalous pulmonary venous connection (or drainage), or partial anomalous pulmonary connection, respectively. Pulmonary vein The pulmonary veins are the veins that transfer oxygenated blood from the lungs to the heart. The largest pulmonary veins are the four "main pulmonary veins", two from each lung that drain into the left atrium of the heart. The pulmonary veins are part of the pulmonary circulation. Two main pulmonary veins emerge from each lung hilum, receiving blood from three or four bronchial veins apiece and draining into the
Superior mesenteric vein can be fatal. It is estimated that 10-15% of mesenteric ischemia is due to mesenteric thrombosis. Superior mesenteric vein The superior mesenteric vein (SMV) is a blood vessel that drains blood from the small intestine (jejunum and ileum). At its termination behind the neck of the pancreas, the SMV combines with the splenic vein to form the hepatic portal vein. The SMV lies to the right of the similarly named artery, the superior mesenteric artery, which originates from the abdominal aorta. Tributaries of the superior mesenteric vein drain the small intestine, large intestine, stomach, pancreas and appendix and include: Thrombosis