Artery away from the heart to the tissues, except for pulmonary arteries, which carry blood to the lungs for oxygenation (usually veins carry deoxygenated blood to the heart but the pulmonary veins carry oxygenated blood as well). There are two types of unique arteries. The pulmonary artery carries blood from the heart to the lungs, where it receives oxygen. It is unique because the blood in it is not "oxygenated", as it has not yet passed through the lungs. The other unique artery is the umbilical artery, which carries deoxygenated blood from a fetus to its mother. Arteries have a blood
Tail vein Tail vein Tail vein or caudal vein is the largest vein in vertebrate animals' tail. It leads directly into the posterior cardinal vein in the posterior trunk in fishes. Mammal caudal vein (the middle caudal vein) leads to inferior vena cava. Caudal vein is one of the many places from which a laboratory worker can withdraw blood from a mouse specimen. The process does not require the death of the mouse, that is, assuming that not too much more than the established standard of "no more than two blood samples are taken per session and in any one 24-hour period.".