B3 - Homeostasis Flashcards
Why do we need homeostasis?
To keep things at a specific level.
What does homeostasis control? [6]
Temperature, water, ions, blood sugar, CO2, urea.
What is the thermoregulatory centre?
A personal thermostat in the brain.
How does the thermoregulatory centre work?
Receptors that are sensitive to blood temperature send impulses with information of the skin temperature.
What happens if you’re too hot? [3]
Hairs lie flat.
Swear is produced.
Blood vessels dilate.
Why do blood vessels dilate if you’re too hot?
So it’s easier to transfer heat from the blood.
What happens when you’re too cold? [4]
Hairs stand on end.
No sweat.
Blood vessels constrict.
Shivering.
Why do your hairs stand on end when you’re cold?
To create an insulating layer.
Why do your blood vessels constrict when you’re cold?
To close off the skin’s blood supply.
Why do you shiver when you’re cold?
Shivering needs respiration which releases energy to warm the body.
What is homeostasis?
Maintaining a constant internal environment.
