The pulmonary circulation is the portion of the circulatory system which carries deoxygenated blood away from the right ventricle of the heart, to the lungs, and returns oxygenated blood to the left atrium and ventricle of the heart.[1] The term pulmonary circulation is readily paired and contrasted with the systemic circulation. The vessels of the pulmonary circulation are the pulmonary arteries and the pulmonary veins.
Pulmonary circulation
Human pulmonary circulation. Oxygen-rich blood is shown in red; oxygen-depleted blood in blue

Pulmonary circulation in the heart
DetailsSystemCirculatory systemAnatomical terminology
A separate system known as the bronchial circulation supplies oxygenated blood to the tissue of the larger airways of the lung.
The earliest human discussions of pulmonary circulation date back to Egyptian times. Human knowledge of pulmonary circulation grew gradually over centuries, and scientists Ibn al-Nafis, Michael Servetus, and William Harvey provided some of the first accurate descriptions of this process.