Which anatomical structure in large arteries provides elasticity and recoil during the cardiac cycle?

Which anatomical structure in large arteries provides elasticity and recoil during the cardiac cycle?

• A. Elastic fibers organized into elastic lamellae in the tunica media.
• B. Collagen fibers in parallel bundles of the tunica media.
• C. Smooth muscle in the tunica intima.
• D. Elastic fibers in the endothelium.

Answer: (B)

Elasticity and recoil in large arteries come from elastic fibers organized into concentric elastic lamellae within the tunica media. These lamellae stretch when the heart pumps blood and snap back during diastole, helping to dampen the pulse and keep blood flow steady. Collagen fibers provide strength but don’t confer the same stretchy recoil, smooth muscle in the tunica media mainly modulates vessel diameter rather than elasticity, and the endothelial layer lining the lumen lacks elastic fibers. So the elastic lamellae in the tunica media are the structure that enables this elastic recoil.

Elasticity and recoil in large arteries come from elastic fibers organized into concentric elastic lamellae within the tunica media. These lamellae stretch when the heart pumps blood and snap back during diastole, helping to dampen the pulse and keep blood flow steady. Collagen fibers provide strength but don’t confer the same stretchy recoil, smooth muscle in the tunica media mainly modulates vessel diameter rather than elasticity, and the endothelial layer lining the lumen lacks elastic fibers. So the elastic lamellae in the tunica media are the structure that enables this elastic recoil.