9.3.4 - Thermoregulation

Question 1

What are examples of ectotherms?

Answer 1

Mammals and birds

Question 2

How does the hypothalamus control body temperature?

Answer 2

Receives information as electrical impulses from sensory neurons.
Processes information in thermoregulatory centre.
Send impulses via motor neurons to effectors to correct body temperature.

Question 3

What are examples of effectors?

Answer 3

Skin
Blood vessels
Skeletal muscles

Question 4

How does piloercetion work?

Answer 4

Errector muscles in the skin cause hairs to stand on end.
This causes air to be trapped for insulation.

Question 5

How does vasoconstriction work?

Answer 5

Capillaries constrict reducing blood flow in capillaries near skin so heat loss is avoided.

Question 6

How does vasodilation work?

Answer 6

Capillaries dilate, increasing blood flow to the skin increasing heat loss. (arteriole end dilates)

Question 7

How does sweating cool you down?

Answer 7

When sweat evaporates it takes heat energy with it, cooling the skin.

Question 8

How does shivering keep you warm?

Answer 8

Muscles contract and relax quickly.
Some energy produced in respiration (exothermic) warms up the body.