The pulmonary artery have light violet blood.Why?
Answers
In the lung the transfer of oxygen from room air to erythrocytes is carried out. Those red blood cells then "carry" their oxygen load to tissues, where they are unloaded, called "desaturated". Oxygen rich blood is light red, desaturated blood is dark red to violet. Arteries carry oxygenated blood to tissues, desaturated blood is carried back to the heart by the venous system. Therefore arterial blood is light red, venous blood is violet. That assumption however is only valid for the "main system", not for the pulmonary blood circulation. Venous (desaturated) blood enters the heart by the right atrium, is passing to the right ventricle, is pumped through the lungs, enters left atrium, followed by left ventricle and then pumped into the tissues. Vessels leading away from the heart are called "artery", vessels leading to the heart"veins". In the pulmonary system the heart ist pumping desaturated ("Venous") blood to the lung, lung veins coming from the lung leading to the heart carry saturated ("arterial") blood. Therefore lung arteries carry violet (desaturated or "venous") blood, which is violet.