Define pulmonary veins

Question

Define pulmonary veins and also find out their number?

Answer 1

The pulmonary veins are portion of the pulmonary circulation. They are vessels which carry oxygen-rich (or arterial) blood from the lungs to heart. There are four pulmonary veins, two which drain blood from the right lung and other two which drain the left lung. The pulmonary veins debouch into left atrium bringing arterial blood to heart. Though they are veins, they carry arterial blood and not the venous blood.