What is "pulmonary vein"?

The pulmonary veins are a set of four blood vessels that transport oxygenated blood from the lungs to the heart. Two pulmonary veins arise from the left lung and two from the right lung. They are responsible for delivering oxygen-rich blood back to the heart, where it is then pumped to the rest of the body to nourish tissues and organs. The pulmonary veins play a vital role in systemic circulation and are essential for maintaining a healthy oxygen supply throughout the body.