Pulmonary vein

The pulmonary veins are the veins that carries oxygenated blood from the lungs to the heart. They are the only veins in the body that carries oxygenated blood; they also differ from the other veins in that they do not have valves.
There are four pulmonary veins: the left and right superior and inferior veins. These enter the heart via the left atrium.
Pulmonary vein at Wikipedia
Category:Anatomy