Which circulation carries venous blood from the right atrium to the lungs for oxygenation and back to the left atrium?

• A. Systemic Circulation
• B. Pulmonary Circulation
• C. Coronary Circulation
• D. Cerebral Circulation

Answer: (B)

The main idea is the pathway that handles gas exchange with the lungs. Blood from the body returns to the heart and enters the right atrium, then moves to the right ventricle and is pumped to the lungs through the pulmonary arteries. In the lungs, blood drops off carbon dioxide and picks up oxygen, becoming oxygenated. It then returns to the heart via the pulmonary veins into the left atrium. This complete route—right atrium to lungs to left atrium—is the pulmonary circulation.

This is distinct from systemic circulation, which sends oxygenated blood to the rest of the body; coronary circulation, which nourishes the heart muscle itself; and cerebral circulation, which supplies the brain.