The pulmonary circuit is a part of the cardiovascular system responsible for transporting deoxygenated blood from the heart to the lungs and returning oxygenated blood back to the heart. Blood is pumped from the right ventricle through the pulmonary arteries to the lungs, where it releases carbon dioxide and absorbs oxygen. Once the blood is oxygenated in the lungs, it travels back to the heart via the pulmonary veins into the left atrium. This process is essential for maintaining the body's oxygen supply and removing carbon dioxide, supporting overall health and function.