Blood air to all of the cells of the body, and venous blood carries carbon dioxide, a waste product of metabolism by cells, to the lungs to be exhaled. However, one exception includes pulmonary arteries, which contain the most deoxygenated blood in the body, while the pulmonary veins contain oxygenated blood. Additional return flow may be generated by the movement of skeletal muscles, which can compress veins and push blood through the valves in veins toward the right atrium. The blood circulation was famously described by William Harvey in 1628. In vertebrates, the various cells of blood are made in the
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