Question

consider the model of temperature regulation in humans. instead of an increase in temperature, as seen here, imagine that the human body temperature drops. explain how this model would most likely change in response to a drop in temperature? a signals from the hypothalamus would stop. b the blood vessels move up and down in the skin. c vasodilation would be replaced by vasoconstriction. d the vasodilation step in the model would include shivering.

Explanation:

When body temperature drops, the hypothalamus activates a response. Vasodilation (widening of blood vessels to release heat) is replaced by vasoconstriction (narrowing of blood vessels to conserve heat). This helps retain body heat. Option A is incorrect as hypothalamus signals would not stop but change. Option B is wrong as blood vessels don't move up and down. Option D is incorrect as vasodilation is replaced, not combined with shivering (shivering is a separate heat - generating mechanism).

Answer:

C. Vasodilation would be replaced by vasoconstriction.