Co-ordination and response

Question 1

What does homeostasis control?

Answer 1

Body temperature, water and blood sugar.

Question 2

How are organisms are able to respond to changes in their environment?

Answer 2

Animals and plants need to be able to respond to changes in their internal and external environment (such as changes in temperature or pH) and to coordinate the activities of their different organs.

Homeostasis maintains the internal environment within restricted limits. It’s critically important for organisms as it ensures the maintenance of optimal conditions for enzyme action and cell function.

Examples of physiological factors that are controlled by homeostasis in mammals include:
- Body temperature
- Metabolic waste (eg. carbon dioxide and urea)
- Blood pH
- Concentration of glucose in the blood
- Water potential of the blood
- Concentration of respiratory gases (carbon dioxide and oxygen) in the blood

There are two communication systems in mammals that do this:
The nervous system
The endocrine system