Question

. You may have heard of "polar bears," or people who choose to swim in the ocean during the winter months (often for charity). What happens to arterioles in the feet of a "polar bear" when they first step into ice cold water? The arterioles in the feet of the "polar bear" will constrict completely, resulting in his or her feet being severely oxygen deprived. The arterioles in the feet of the "polar bear" will neither constrict nor dilate, as vessel diameter is independent of changes in temperature. Arterioles will likely constrict to prevent the "polar bear" from losing heat from his or her feet. Arterioles will likely dilate, providing more heat to the feet and toes. As feet placed in cold water will begin to shiver (and lose energy), the arterioles will dilate to provide cells of the "polar bear's" feet and toes with more O2 to be used during cellular respiration.

Answer 1

Arterioles will likely constrict to prevent the "polar bear" from losing heat from his or her feet.

Step-by-step explanation:

Polar bears and humans are mammals and warm-blooded animals that maintain constant body temperature at the expense of metabolic heat. The skin of polar bear and humans serve in thermoregulation to regulate the body temperature. In response to the lower temperature of surroundings, the blood vessels present in the dermis of skin are constricted. This is done to reduce the blood flow through the skin and thereby reduce the loss of heat from the body.

As the polar bear and humans step in ice and cold water respectively, the arterioles present in their skin would become narrow to slow down the blood flow and thereby, to prevent the heat loss.