What is the role of the pulmonary vein?

The pulmonary vein's primary function is to carry oxygenated blood from the lungs back to the heart. After the process of gas exchange in the lungs, where carbon dioxide is released and oxygen is absorbed, the oxygen-rich blood is collected by the pulmonary veins. These vessels transport the oxygenated blood to the left atrium of the heart, where it is then pumped into the left ventricle and subsequently distributed throughout the body to nourish tissues and organs.

This role is essential for maintaining the oxygen supply needed for cellular respiration, which is crucial for all bodily functions. Understanding the specific function of the pulmonary veins helps highlight the difference between veins that carry oxygenated and deoxygenated blood, as most veins in the body transport deoxygenated blood, whereas the pulmonary veins are a unique exception.