GCSE Biology Unit 2 (18)

Homeostasis

• Homeostasis is the maintenance of a constant internal environment
• There are six main things that need to be controlled.
• 1) The body temperature mustn't get too high or low.
• 2) Water content mustn't get too high or low, or too much water could move in and out of cells and damage them.
• 3) If the ion content of the body is wrong, the same thing could happen.
• 4) The blood sugar level must stay within certain limits.
• The last 2 things are waste products that are constantly produced in the body that you have to get rid of.
• 5) Carbon dioxide is a product of respiration. It is toxic in high quantities so it has to be removed. It leaves the body by the lungs when you breathe out.
• 6) Urea is a waste product made from excess amino acids that also has to be removed.
• Body temperature must be…