During hot environmental conditions, negative feedback mechanisms trigger vasodilation in the skin. Vasodilation helps restore normal body temperature by:
Answer and explanation
Correct answer: D. Increasing blood flow to surface capillaries to facilitate heat loss via radiation.
- Step 1: In response to elevated core or ambient temperatures, thermoreceptors signal the hypothalamus to activate cooling mechanisms, leading to the relaxation of smooth muscle in precapillary sphincters and dermal arterioles.
- Step 2: This widening of blood vessels (vasodilation) increases blood flow through superficial capillary beds close to the epidermal surface, enabling thermal energy to be radiated and convected away from the body into the environment.
Answer
Increasing blood flow to surface capillaries to facilitate heat loss via radiation.
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