Which vessel carries deoxygenated blood from the heart to the lungs for gas exchange?

• A. Pulmonary Trunk
• B. Left Subclavian Artery
• C. Superior Vena Cava
• D. Descending Aorta

Answer: (A)

In the pulmonary circulation, the heart sends deoxygenated blood to the lungs through the pulmonary trunk. This vessel carries blood pumped from the right ventricle and soon divides into the left and right pulmonary arteries that travel to the lungs for gas exchange. After the lungs oxygenate the blood, it returns to the heart via the pulmonary veins into the left atrium to enter systemic circulation.

The left subclavian artery is part of the systemic circulation and delivers oxygen-rich blood to the left arm. The superior vena cava brings deoxygenated blood from the head, neck, and upper body back to the right atrium. The descending aorta distributes oxygenated blood to the rest of the body.