What is pulmonary circulation?

• A. Blood flow within the heart chambers
• B. Blood flow from the body to the heart
• C. Blood flow between the heart and lungs
• D. Blood flow in the arteries of the limbs

Answer: (C)

Pulmonary circulation is the part of the circulatory system that moves blood between the heart and the lungs to enable gas exchange. It starts with the right ventricle pumping deoxygenated blood into the pulmonary arteries, carrying it to the lungs. In the lungs, blood releases carbon dioxide and picks up oxygen. The oxygen-rich blood then returns to the heart through the pulmonary veins and enters the left atrium. This loop is separate from systemic circulation, which sends blood to the rest of the body. So, pulmonary circulation specifically describes the heart–lungs–heart pathway responsible for oxygenating blood before it nourishes the body.