Which vessel is the largest in the body?

• A. Pulmonary Vein
• B. Aorta
• C. Pulmonary Artery
• D. Capillary

Answer: (B)

Vessels vary in size, and the largest single vessel in the body is the aorta, the main artery that carries blood from the heart to the rest of the body. Its lumen is the widest among blood vessels, which fits its job of handling a large volume of blood pumped from the left ventricle at high pressure. The pulmonary artery is large but narrower than the aorta, and it goes to the lungs. The pulmonary veins return blood to the heart and aren’t as wide as the aorta either. Capillaries are tiny tubes, the smallest individual vessels, though there are many of them. So the aorta stands out as the largest single vessel.