Which circulation moves deoxygenated blood from the heart to the lungs and returns oxygenated blood to the heart?

• A. Pulmonary circulation
• B. Systematic circulation
• C. Coronary circulation
• D. Portal circulation

Answer: (A)

The flow described is the pathway that handles gas exchange with the lungs. In this circuit, blood that is low in oxygen (deoxygenated) leaves the heart’s right side and is pumped to the lungs. There, it releases carbon dioxide and picks up oxygen, and then the oxygen-rich blood returns to the heart to enter the left atrium. This is pulmonary circulation—the loop between the heart and lungs.

To contrast briefly, systemic circulation moves oxygenated blood from the left ventricle to the rest of the body and returns deoxygenated blood to the right atrium; coronary circulation supplies the heart muscle itself; portal circulation describes blood moving from the digestive organs to the liver.