Introduction to Homeostasis

Homeostasis is the term used for the body’s ability to maintain a constant internal environment. This condition is important for the proper functioning of the body because the enzymes that control all metabolic activity essential for life, are very sensitive to changes in their environment. This constant state must be maintained in spite of changing the external environment.


Species that have efficient homeostasis systems are able to tolerate a wide range of external factors. Apart from water, which is regulated by the kidneys (the kidneys are responsible for maintaining the levels of mineral salts as well), other substances and conditions must be kept relatively constant such as carbon dioxide concentration, blood glucose levels, and body temperature.


An example of homeostasis is the control of blood sugar levels in the human body. If carbohydrates are ingested in excess, they will be digested and the excess converted to animal starch (also known as glycogen) by the linking of glucose molecules. This is accomplished by the hormone insulin which is secreted from the pancreas.


We know what happens when carbohydrates are ingested in excess, but what happens if we skip a meal? The first thing is we often feel a bit weak as there is a lack of sugar in the body. As a result, the body begins to actively convert glycogen back to glucose, in order to increase the blood glucose level.

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