Which circulation system takes oxygen-poor blood to the lungs for oxygenation?

• A. Pulmonary circulation
• B. Systemic circulation
• C. Coronary circulation
• D. Renal circulation

Answer: (A)

Oxygen-poor blood is moved to the lungs for oxygenation by the pulmonary circulation. This path starts in the right side of the heart, where deoxygenated blood is pumped into the pulmonary trunk and travels through the pulmonary arteries to the lungs. In the lung capillaries, blood releases carbon dioxide and picks up oxygen. The now oxygen-rich blood returns to the heart via the pulmonary veins into the left atrium, ready to be pumped to the rest of the body. This circuit is distinct from systemic circulation, which sends oxygenated blood to body tissues, as well as from specialized circulations that nourish the heart muscle and the kidneys.