SDN Members don't see this ad. (About Ads) there are 4 total pulmonary veins...only thing i can find is that each lung has 1 pulmonary artery with 2 pulmonary veins leaving heading to the Left atrium. Is this right? What is the purpose of 2 veins from the lungs instead of one? So does this mean there are actually 4 holes where each vein empties into the left atrium? Anyone understand my confusion?