Changing the way you learn

B3 - Homeostasis

Homeostasis is the maintenance of a constant internal envrionment
Six thing that need to be controlled
1. Body temperature, Water content (too high/low, too much move into/out of cells and damage them, Ion content( same thing could damage cells), blood sugar levels
2. Two waste products
  1. CO2 product of respiration. Toxic qualities need to be removed. Urea made from excess amino acids.
Body temperature must be carefully controlled. Enzymes in a human body work best around 37C. Otherwise the enzymes wont work properly and some really important reactions could be disrupted
1. There is a thermoregulatory centre in the brain which acts as a personal thermostat. It contains receptors that are sensitive to the temperature of the blood flowing through the brain.
  1. It also receives impulses from the skin, giving information about skin temperature.
When you're too hot, hairs lie flat, sweat is produced by sweat glands and evaporates from skin, removing heat. Blood vessels supplying the skin dilate so more blood flows close to the surface of the skin. This means it is easier for heat to be transferred from the blood to the environment.
When you're too cold, hairs stand up to trap an insulating layer of air, no sweat is produces,blood vessels supplying skin capillaries constrict to close off the skin's blood supply, you shiver. This needs respiration which releases some energy to warm the body.

B3 - Homeostasis

	Created by Lily O'Brien over 7 years ago