# Regulators

Regulators are able to withstand differences in their external environment because they can control their internal environment.

This allows regulators to increase the possible ecological niches that they can inhabit. However, this regulation requires energy, so regulators tend to have high metabolic rates.

The regulation of the internal environment is called homeostasis. This process requires a lot of energy and it is important because it provides enzymes in the body with an optimum temperature at which to work.

It is also important for the diffusion of substances, as diffusion rates are higher in warmer temperatures.

A polar bear is an example of an animal which can regulate its body temperature.

### Homeostasis

The is the body’s temperature monitoring centre in the brain. It is sensitive to nerve impulses that come from receptors in the skin.

The hypothalamus then sends nerve impulses to effectors to change the temperature of the body. Effectors include sweat glands, blood vessels and muscles around the body.