Title: Homeostasis and the Human Body

Key words: cells, environment, oxygen, nutrition, waste products

Date: Aug 2000

Category: 1. The Cell

Type: Article

Author: DJE Candlish

Homeostasis and the Human Body

The human body is a complex structure, composed of billions of cells, organised into organs and tissues which have evolved to carry out specific functions. The human brain, with its 12 billion cells and an almost infinite number of interconnections, may be the most complex structure in existence. Much of the brain is dedicated to co-ordinating the activities of the other organs and tissues within the body and maintaining the optimal environment for the individual cells - a process known as homeostasis. This involves reacting to changes in both the internal and external environment of the body.

Some homeostatic mechanisms ensure that cells receive the oxygen and nutrition they need to function and can dispose of the waste products, such as carbon dioxide, that they produce. Others maintain the temperature, water and mineral content of the body within a narrow range of normal limits.

This is what happens in a healthy body, of course. Illness and disease can disrupt these homeostatic mechanisms and affect the normal functioning of the body in many different ways, reflecting the complexity of the body itself. In the same way, medicines used to treat disease can also affect homeostatic mechanisms in different ways. They can either correct the imbalances caused by the disease or cause imbalances of their own, which are detected by the individual as 'side-effects' of their treatment.