B3.3.2 Temperature control

Question 1

How does sweating prevent the body from overheating?

Answer 1

The sweat absorbs the body’s heat energy and then evaporates, removing the heat energy from the body.

Question 2

How do blood vessels (vasodilation) prevent the body from overheating?

Answer 2

The blood vessels supplying the skin capillaries dilate causing more blood to flow nearer the surface of the skin, the skin to become red in appearance, and an increase in heat loss.

Question 3

How do blood vessels (vasoconstriction) prevent the body from becoming too cold?

Answer 3

The blood vessels supplying the skin capillaries constrict, causing less blood to flow nearer the surface of the skin, the skin to become pale in appearance, and a reduction of heat loss.

Question 4

How does shivering prevent the body from becoming too cold?

Answer 4

The twitching of muscles generates additional heat as their contraction causes the muscles to respire, releasing energy to warm the body.

Question 5

How does the body regulate temperature?

Answer 5

Temperature receptors in the skin detect a change in temperature and send signals to the thermoregulatory centre in the brain which releases certain hormones to control body temperature.

Question 6

What happens to body hairs to prevent the body from overheating?

Answer 6

The hairs lie flat so that they do not trap an insulating layer of air.

Question 7

What happens to the body hairs to prevent the body from becoming too cold?

Answer 7

The hairs raise to create an insulating layer of air.