Explain how negative feedback mechanisms help the body achieve homeostasis

Homeostasis at its core simply means the maintenance of balance – the body is said to achieve homeostasis when there is there is a balance between the ever-changing external environment and the relatively constant conditions within the body which are kept within a narrow range. Negative feedback back is a mechanism that allows the body to maintain homeostasis and keep the conditions within the body constant. When there is a change in a process within the body, for example, a change in the volume of a cell – cell volume is typically kept constant. This change is detected and mechanisms are activated to correct this change and return the body back to a normal state. Once the normal, homeostatic, state is achieved the mechanisms are switched off.

In the case of changes to a cell's volume, the cell opens channels which allow the movement of water and ions either water moving out of the cell to decrease volume or moving into the cell to increase volume back to normal. Once the cell's volume is back to normal these channels are closed.