carbon dioxide
Pulmonary circulation is the part of the circulatory system that carries blood between the heart and lungs the term pulmonary means of the lungs . It is illustrated in Figure below . Deoxygenated blood leaves the right ventricle through pulmonary arteries, which transport it to the lungs. In the lungs, the blood gives up carbon dioxide and picks up oxygen. The oxygenated blood then returns to the left atrium of the heart through pulmonary veins.