Skin

Question 1

Vasodilation

Answer 1

Heat loss by convection, radiation

Relaxed arteriole muscle

Question 2

Vasoconstriction

Answer 2

Less blood flow to surface
Contract arteriole
Blood kept away from surface

Question 3

Temp control in skin

Answer 3

Controlled, for enzymes
Thermoregulatory centre in brain
BT too low
Hypothalamus, VC, hairs stand, shiver
BT too high
Hypothalamus, VD, sweat, hair flat

Question 4

Protection

Answer 4

Melanin, absorb UV
Tanning, more melanin
Layers of dead cells, stops bacteria entering, limits water loss, through evaporation

Question 5

Sensitivity

Answer 5

Touch, pressure, heat, cold, pain sensors

Aware of problem, react to it

Question 6

Temp regulation

Answer 6

Small BV
Sweat glands
Hair muscles

Question 7

Sweating

Answer 7

Sweat glands pour sweat on skin, evaporate, takes heat away

Heated blood flows near sweat gland, contains water, travels up gland, evaporate

Question 8

Shivering

Answer 8

Uncontrollable muscle contraction in limbs

Releases heat, chem changes in muscle

Question 9

Goosebumps

Answer 9

Erector muscles contract, hair upright

Traps layer of air, insulator