What is the difference between a pulmonary artery and the pulmonary vein?

While veins usually carry deoxygenated blood from tissues back to the heart, in this case, pulmonary veins are among the few veins that carry oxygenated blood instead. Oxygenated blood from the lungs is circulated back to the heart through the pulmonary veins that drain into the left atrium. pulmonary vein - a vein carrying oxygenated blood from the lungs to the left atrium of the heart.

pulmonary artery - the artery carrying blood from the right ventricle of the heart to the lungs for oxygenation.

Function. While veins usually carry deoxygenated blood from tissues back to the heart, in this case, pulmonary veins are among the few veins that carry oxygenated blood instead. Oxygenated blood from the lungs is circulated back to the heart through the pulmonary veins that drain into the left atrium.