In normal conditions, there are four pulmonary veins in our bodies that carry oxygenated blood from both the lungs separately into the left atrium, these four pulmonary veins work as follows:(a) the right superior pulmonary vein does the work of draining the upper right along with middle lobes; (b) the left superior pulmonary vein does the work of draining the left upper lobe along with lingula, and (c) then there are also two inferior pulmonary veins.The left inferior pulmonary vein does the work of draining the lower left lobe. The right superior pulmonary vein does the work of draining the upper right along with the middle lobe. The right inferior pulmonary vein does the work of draining the lower right lobe.