In response to cold, which vascular change is most likely in the skin?

In response to cold, which vascular change is most likely in the skin?

• A. Arterioles experience vasoconstriction
• B. Shunt vessel experiences vasodilation
• C. Veins experience vasodilation
• D. Capillaries experience vasodilation

Answer: (A)

When the body is cold, the goal is to conserve heat by reducing heat loss from the skin. The most effective way to do this is by constricting the small arteries that supply the skin—the arterioles. When these arterioles constrict, their resistance to blood flow increases, so less warm blood reaches the surface and less heat is radiated away. This response is driven by the sympathetic nervous system releasing signals that cause smooth muscle in the arteriolar walls to tighten. If shunt vessels, capillaries, or veins were to dilate, more blood could reach the surface or be stored in skin vessels, increasing heat loss, which is not what the body aims for in the cold.

When the body is cold, the goal is to conserve heat by reducing heat loss from the skin. The most effective way to do this is by constricting the small arteries that supply the skin—the arterioles. When these arterioles constrict, their resistance to blood flow increases, so less warm blood reaches the surface and less heat is radiated away. This response is driven by the sympathetic nervous system releasing signals that cause smooth muscle in the arteriolar walls to tighten. If shunt vessels, capillaries, or veins were to dilate, more blood could reach the surface or be stored in skin vessels, increasing heat loss, which is not what the body aims for in the cold.