Controllimg Body Temperature

Question 1

Importance of controlling body temperature

Answer 1

• optimum of 37°C for enzyme action
• energy input/output balance keeps core temperature constant

Question 2

Where is body temperature controlled?

Answer 2

• thermoregulatory centre in hypothalamus of the brain
• contains temperature-sensitive receptors to blood flowing
• impulses recovered from temperature receptors in skin

Question 3

Regulating low body core temperature

Answer 3

• low core temperature detected by receptors
• thermoregulatory centre coordinates response to trigger effectors to counteract change
• hairs erect to trap insulating layer of air
• vasoconstriction, blood vessels constrict to close off skin’s blood supply
• shivering, requires respiration which transfers energy to warm the body

Question 4

Regulating high body core temperature

Answer 4

• high body core temperature detected by receptors
• thermoregulatory centre coordinates response to trigger effectors to counteract change
• sweat glands produce sweat that evaporate which transfers energy to environment
• vasodilation, blood vessels dilate so blood flows closer to the skin, transfers energy to environment
• hair erector muscles relax