controlling body temperature

Question 1

describe what happens when you’re too hot

Answer 1

• hair erector muscle relaxes so hairs lie flat
• sweat is produced by sweat glands and evaporates from the skin to transfer energy to the environment
• vasodilation: blood vessels supplying the skin dilate so more blood flows close to the surface of the skin to transfer energy from the skin to the environment

Question 2

describe what happens when you’re too cold

Answer 2

• hair erector muscle contract so hairs stand up to trap and insulating layer of air
• no sweat is produced to conserve energy
• vasoconstriction: blood vessels supplying the skin constrict to close off the skin’s blood supply, reducing unwanted energy transfers
• muscles contract to shiver, transferring energy to warm the body through respiration

Question 3

how does the dilation of blood vessels decrease temperature?

Answer 3

• blood vessels supplying capillaries widen so it increases the flow of blood to the surface of the skin
• allows more heat and energy to be lost to the environment
• cools you down as less heat is conserved

Question 4

how does the constriction of blood vessels increase temperature?

Answer 4

• blood vessels constrict so it decreases the flow of blood
• allows less heat and energy to be lost to the environment
• heats you up as more heat is conserved to be used

Question 5

how is body temp controlled by negative feedback?

Answer 5

temp receptors detect change in temp, thermoregulatory centre acts as a coordination centre - receives information from receptors and triggers effectors, effectors produce a response to counteract change

Question 6

how does shivering increase temperature?

Answer 6

• muscle contraction so respiration occurs, releasing heat energy