Which feature enables arteries to withstand the pressure generated by each heartbeat?

• A. Elastic properties allow stretch and recoil
• B. Strong, tough walls
• C. High density of valves
• D. Large number of capillaries

Answer: (B)

Arteries endure the pulse of each heartbeat thanks to their elastic walls. Elastic fibers in the vessel walls allow them to stretch as blood is ejected during systole and then recoil during diastole, which smooths out the pressure surge and keeps blood moving forward. This stretch-and-recoil capability helps absorb the high pressure without rupturing. The thick, muscular walls provide structural strength, but the essential feature that directly counters the pulsatile load is elasticity. Valves aren’t a feature of arteries (they’re mainly in veins), and a large number of capillaries isn’t related to resisting arterial pressure.