thermoregulation

Question 1

the skin is our largest…

Answer 1

sense organ

Question 2

what is the free nerve ending sensitive to?

Answer 2

pain and temperature

Question 3

what is located in the dermis?

Answer 3

touch and pressure receptors are located here

Question 4

when is vasodilation used?

Answer 4

to cool down the body

Question 5

where does heat exchange occur?

Answer 5

at the body’s surface as this is where the body comes into the closest proximity to the enivronment

Question 6

what is vasodilation?

Answer 6

• arterioles supplying the capillaries near the surface of the skin get wider- they dilate
• more warm blood will flow through capillaries near the surface of the skin- more heat will be lost via radiation

Question 7

why do pale- skinned people go red when they are hot?

Answer 7

they are experiencing vasodilation

Question 8

what is sweat secreted by?

Answer 8

sweat glands

Question 9

how does sweating cool the skin?

Answer 9

cools the skin by evaporation which uses heat energy from the body to convert liquid water into water vapour

Question 10

how does the hair erector muscles cool people down?

Answer 10

• hair erector muscles in the skin relax- causing hairs to lie flat
• this stops them from forming an insulating layer by trapping air and allowing air to circulate over skin and heat to leave by radiation

Question 11

what is vasoconstriction?

Answer 11

• arterioles supplying the capillaries near the surface of the skin get narrower- they constrict
• less warm blood will flow through capillaries near the surface of the skin
• less heat will be lost via radiation

Question 12

how do hair erector muscles heat people up?

Answer 12

the hairs trap a layer of air which provides insulation for conduction of heat

Question 13

how does shivering warm people up?

Answer 13

• muscles contract in a rapid and regular manner
• the metabolic reactions required to power this shivering generates sufficient heat to warm the blood and raise the core body temperature