Pulmonary Vein

Blood vessels that carry blood towards the heart are called veins. Pulmonary veins carry ‘pure’ or oxygenated blood from the lungs to the left upper chamber (atrium) of the heart. It is one of the only two veins that carry oxygenated blood. All other veins carry ‘impure’ or deoxygenated blood to the heart. Each lung has two pulmonary veins – one upper (superior) and one lower (inferior). Hence there are totally four pulmonary veins. They arise from a network of pulmonary capillaries that are present around tiny air sacs in the lungs.   Many conditions affect the pulmonary veins. Pulmonary venous hypertension, i.e. increased blood pressure in the pulmonary veins, may be caused by congestive heart failure, damaged valve in the heart, etc. In pulmonary veno-occlusive disease there is widespread occlusion or narrowing of pulmonary veins by fibrous tissue. In certain rare birth defects some or all of the pulmonary veins drain blood into the right atrium. In a rare anomaly of the lung there may be connections between the pulmonary arteries and veins.