1. Homeostasis

2. Glossary Maintain – keep up. Maintain – keep up. Constant – the same. Constant – the same. Internal – inside the body. Internal – inside the body. Environment – surroundings of the body. Environment – surroundings of the body.

3. What is Homeostasis? Body cells work best if they have the correct Body cells work best if they have the correct Temperature Temperature Water levels Water levels Glucose concentration Glucose concentration Your body has mechanisms to keep the cells in a constant environment. Your body has mechanisms to keep the cells in a constant environment.

4. What is Homeostasis? The maintenance of a constant environment in the body is called Homeostasis

5. Controlling body temperature All mammals maintain a constant body temperature. All mammals maintain a constant body temperature. Human beings have a body temperature of about 37ºC. Human beings have a body temperature of about 37ºC. E.g. If your body is in a hot environment your body temperature is 37ºC E.g. If your body is in a hot environment your body temperature is 37ºC If your body is in a cold environment your body temperature is still 37ºC If your body is in a cold environment your body temperature is still 37ºC

6. Penguins huddling to keep warm

7. What is one mechanism used to cool the body down? Sweating When your body is hot, sweat glands are stimulated to release sweat. When your body is hot, sweat glands are stimulated to release sweat. The liquid sweat turns into a gas (it evaporates) The liquid sweat turns into a gas (it evaporates) To do this, it needs heat. To do this, it needs heat. It gets that heat from your skin. It gets that heat from your skin. As your skin loses heat, it cools down. As your skin loses heat, it cools down.

8. Sweating The skin