Homeostasis

• Homeostasis

  • Enzymes and cells require stable conditions in order to function - cannot work well if conditions around them change too much
  • Our bodies have systems in place to keep internal conditions optimum for the cells to function
• Homeostasis

  The regulation of internal conditions of a cell or organism to maintain optimum conditions for function - in response to internal and external changes
• Internal conditions

  • Any sort of exercise will place demands on the body (e.g. cycling)
  • E.g. respiration will use glucose to generate energy - which can cause the blood glucose concentration to fall
  • Body temperature will rise and lose water through sweating
• Internal conditions

  • Blood glucose concentration
  • Body temperature
  • Water levels

  These should all remain constant.
• Automatic control systems

  • Involves nervous system or hormones
  • Receptor cells - detect changes in the environment (stimulus)
  • Environment - body's internal conditions (glucose concentration) or external conditions (skin temperature)
  • Receptor cells then pass information to a coordination centre (e.g. brain, spinal cord or pancreas)
  • Coordination centre receives and processes the information from the receptor cells
  • Coordination centre then sends instructions to the effector (muscle or gland)
  • Role of the effector - to carry out the response (restore the optimum level)