Homeostasis - Regulating Body Temperature

What is thermoregulation?

• Thermoregulation is the maintenance of core body temperature.

How does thermoregulation work in cold conditions?

1. Vasoconstriction - the narrowing of blood vessels

2. Piloerection (goosebumps) - hairs stand up creating a layer of still air acting as insulation

3. Shivering - alternative contraction and relaxation of small skeletal muscle groupd

What is the stimulus response model for thermoregulation in cold conditions?

• Stimulus - Decrease in body temperature below normal

• Receptor - Decrease detected by thermoreceptors in skin, organs, and hypothalamus in the brain

• Control Centre - Hypothalamus sends signals via nerve and hormonal systems to effectors

• Effectors - Blood vessels in skin, skeletal muscles

• Response - Reduced blood flow in skin vessels

How does thermoregulation work in hot conditions?

1. Vasodilation - The widening of blood vessels to increase blood flow

2. Sweating - The evaporation of sweat requires heat energy, and this is taken from blood vessels close to the skin, thus cooling the body

What is the stimulus response model for thermoregulation in hot conditions?

1. Stimulus - Increase in body temperature above normal

2. Receptor - Increase detected by thermoreceptors in skin, organs, and hypothalamus

3. Control Centre - Hypothalamus sends signals via nerves to effectors

4. Effector - Blood vessels in skin, sweat glands

5. Response - Vasodilation of skin vessels, sweating