Veins are ___________, tube-like vessels that carry blood to the heart.

Veins are ___________, tube-like vessels that carry blood to the heart.

• A. Thin-walled
• B. Thick-walled
• C. Very tiny
• D. Large, thick

Answer: (A)

Veins are thin-walled, tube-like vessels that carry blood back to the heart. They operate under lower pressure than arteries, so their walls don’t need to be as muscular or elastic. This thinner wall design helps veins return blood through the body, often aided by surrounding muscles and valves that prevent backflow. In contrast, arteries have thick, muscular walls to withstand the higher pressures from the heart, which is why describing veins as thick-walled would be incorrect.

Veins are thin-walled, tube-like vessels that carry blood back to the heart. They operate under lower pressure than arteries, so their walls don’t need to be as muscular or elastic. This thinner wall design helps veins return blood through the body, often aided by surrounding muscles and valves that prevent backflow. In contrast, arteries have thick, muscular walls to withstand the higher pressures from the heart, which is why describing veins as thick-walled would be incorrect.