ATI Pathophysiology Practice Exam

Peripheral vasodilation results in heat loss through which of the following processes?

1. Convection

2. Conduction

3. Radiation

4. Evaporation

The correct answer is: Radiation

Peripheral vasodilation contributes to heat loss primarily through radiation. When blood vessels dilate, more warm blood flows to the surface of the skin, increasing the surface temperature. This allows heat to dissipate into the surrounding environment in the form of infrared radiation. Radiation is the transfer of heat in the form of electromagnetic waves, and it does not require direct contact between objects or a medium, which makes it a significant mechanism for heat loss in warm environments. As the body temperature increases and peripheral blood flow increases due to vasodilation, the body radiates heat more effectively to the cooler air around it, helping to maintain thermal balance. In this context, the other processes—convection, conduction, and evaporation—play roles in heat loss but are not the primary means facilitated by peripheral vasodilation. Convection involves heat transfer through movement of air or fluid, conduction refers to direct contact transfer of heat between materials, and evaporation pertains to the loss of heat when liquid (like sweat) changes to vapor, which is influenced by other mechanisms in addition to vasodilation. However, the immediate effect of peripheral vasodilation is most closely associated with the radiative loss of heat.