Homeostasis (AQA GCSE Biology)

Homeostasis: Basics

What is homeostasis in biology?

• Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes

• Homeostasis maintains optimal conditions for enzyme action and all cell functions

• In the human body, these include control of:

  • Blood glucose concentration

  • Body temperature

  • Water levels

Control of Homeostasis

• Maintaining controlled conditions within the body is under involuntary (automatic) control

• This means that the brain stem (or non-conscious part of the brain) and the spinal cord are involved in maintaining homeostasis – you don’t consciously maintain your body temperature or blood glucose level

• These automatic control systems may involve nervous responses or chemical responses

• All control systems include:

  • Cells called receptors, which detect stimuli (changes in the environment)

  • Coordination centres (such as the brain, spinal cord and pancreas) that receive and process information from receptors

  • Effectors (muscles or glands) which bring about responses which restore optimum levels