Principles of homeostasis

Homeostasis refers to the regulation and maintenance of a stable internal environment within an organism, despite changes in external conditions or physical activity.
Homeostatic mechanisms work based on the principle of negative feedback, in which a change in a particular direction triggers a response in the opposite direction.
Homeostasis involves control systems, which include components like receptors, control centre, and effectors. These systems can adjust the body’s functions in response to change.
These responses include adjusting the heart rate, controlling blood glucose levels, maintaining body temperature, and keeping water and electrolyte balance.
Maintaining homeostasis allows the body’s cells to function optimally and keeps the organism healthy.

Negative feedback acts to counteract changes in the body, maintaining conditions within specific limits.
When a level (e.g. blood glucose) rises above or falls below the norm, a sensor in the body recognises this and triggers a response to restore the normal level.
For example, when body temperature rises, sweat glands are stimulated to produce sweat, which evaporates and cools the body down. If the body temperature drops, muscle shivering is initiated to generate heat.
The key characteristic of negative feedback is that it acts in the opposite direction of the original change, ensuring the stability of the internal environment.

The basic components of a homeostatic control system are the receptor, the control centre, and the effector.
The receptor is a sensor that perceives a change in the environment; this could be an increase in blood glucose, for instance.
The control centre receives and processes the information supplied by the receptor.
The effector provides the means for the control centre’s response to the stimulus; in the case of high blood glucose, this could involve the release of insulin to encourage cells to absorb the excess glucose.
Together, these three components help to maintain homeostasis in the body.

Homeostasis is critical for the normal functioning of the body.
Faulty homeostasis may lead to disease or inefficient functioning.
Conditions such as diabetes and hypothermia can occur when homeostatic mechanisms fail.