In the pulmonary circulation, which vessel carries oxygenated blood to the heart?

• A. Pulmonary arteries
• B. Pulmonary veins
• C. Aorta
• D. Superior vena cava

Answer: (B)

In the pulmonary circuit, blood becomes oxygenated in the lungs and then travels back to the heart through the pulmonary veins. These veins carry the now oxygen-rich blood into the left atrium, from which it moves to the left ventricle and is pumped into the systemic circulation. This is the key distinction: in the lungs, veins return oxygenated blood, whereas arteries carry deoxygenated blood to the lungs. The pulmonary arteries bring deoxygenated blood from the right ventricle to the lungs, the aorta distributes oxygenated blood to the body, and the superior vena cava returns deoxygenated blood from the upper body to the right atrium.