What is pulmonary circuit of the heart?

The pulmonary circuit is powered by the right side of the heart. Its main function is to pump deoxygenated blood which has returned to the heart from the body to the lungs, then back to the heart. The blood is pumped from the heart via the pulmonary artery. The blood is then oxygenated by gas exchange between the alveoli in the lungs and the pulmonary capillaries. The newly oxygenated blood is then returned to the heart by the pulmonary veins, ready to be sent round the body.