Pulmonary vein pulmonary vein lies in front of and a little below the pulmonary artery; the inferior is situated at the lowest part of the lung hilum. Behind the pulmonary artery is the bronchus. The right main pulmonary veins (contains oxygenated blood) pass behind the right atrium and superior vena cava; the left in front of the descending thoracic aorta. Occasionally the three lobar veins on the right side remain separate, and not infrequently the two left lobar veins end by a common opening into the left atrium. Therefore, the number of pulmonary veins opening into the left atrium can vary between
Caput medusae Determine the direction of flow in the veins below the umbilicus. After pushing down on the prominent vein, blood will: Caput medusae Caput medusae, also known as palm tree sign, is the appearance of distended and engorged superficial epigastric veins, which are seen radiating from the umbilicus across the abdomen. The name "caput medusae" (Latin for "head of Medusa") originates from the apparent similarity to Medusa's head, which had venomous snakes in place of hair. It is also a sign of portal hypertension. It is caused by dilation of the paraumbilical veins, which carry oxygenated blood from mother to fetus