One mechanism that some animals use to limit heat loss in cold environments is
A)vasodilation of the near surface blood vessels.
B)vasodilation of below surface blood vessels.
C)vasoconstriction of the precapillary sphincters in the skin.
D)vasoconstriction of veins.
E)increasing cardiac output.

Question

Quizplus · Accepted Answer

Vasoconstriction of the precapillary sphincters in the skin reduces blood flow to the skin's surface and limits heat loss through radiation and convection. This mechanism is used by many animals, including humans, to protect against hypothermia in cold environments. Vasodilation of the near or below surface blood vessels would actually increase heat loss, and vasoconstriction of veins or increasing cardiac output are not effective ways to limit heat loss through the skin.

One Mechanism That Some Animals Use to Limit Heat Loss