P5 - Homeostasis

Homeostasis by definition is the technical term for the process of maintaining a constant internal environment despite changes in the external environment. The internal environment comprises of blood, tissue fluid, body cell contents and all metabolic processes taking place inside the body. This process is essential to the survival of a person and to our species as a whole. The liver, the kidneys, and the brain (hypothalamus, the autonomic nervous system and the endocrine system) help maintain homeostasis. An inability to maintain homeostasis may lead to death or a disease, for example diseases that can occur due to the result of a homeostatic imbalance include diabetes, dehydration, hypoglycaemia, gout and any disease caused by the presence of a toxin in the bloodstream. Lucky though medical intervention can help restore homeostasis and possibly prevent permanent damage to the organs.

How does Homeostasis Work?
Homeostasis occurs due to a control mechanism in the body known as negative feedback. Negative feedback occurs when a key variable, such as the PH of blood and tissue fluid, deviates from the acceptable range, and triggers responses that return the variable to a normal range. In basic terms, negative feedback triggers a response that counteracts the deviation which will allow the variable to stay in the normal range.

The brain and nervous system both play a major role in controlling homeostasis mechanisms. This is due to the fact that both help the body to anticipate when key variables might rise or fall beyond the accepted range and send signals to the effectors to reverse the change and re-establish the original state.

Homeostasis and heart rate
Homeostasis is responsible for managing the heart rate. This is controlled by the autonomic nervous system which as two branches, namely the sympathetic nervous and the parasympathetic nervous system. Both these systems are responsible for managing the heart rate.

The sympathetic nervous