Right ventricle sends blood needing oxygen to the lungs. The blood needing oxygen is pumped out of the right ventricle, through the pulmonary valve into the pulmonary artery. The pulmonary artery then divides into the right and left pulmonary arteries, carrying blood to the right and left lungs.In the lungs the blood gives up its carbon dioxide and picks up oxygen.he purpose of your heart is to pump blood to the organs and tissues of your body that need the oxygen and nutrients it carries. Oxygen-rich blood is pumped out of the left side of your heart (shown on the right in the diagram) into the arteries to these tissues and organs.