homeostasis

• Homeostasis


  The regulation of conditions inside the body to maintain a stable internal environment in response to changes in both internal and external conditions
• Cells in the body

  • Need certain conditions to function properly (not too hot/cold, not too acidic/alkaline, good supply of glucose and water)
• Regulation


  The body regulates everything and makes sure conditions are kept around the right levels
• Temperature and glucose levels do fluctuate but only within small bounds
• Automatic control systems


  • Have three main components: receptors, coordination centres, effectors
  • Communicate via nervous and endocrine systems
• Negative feedback mechanism


  1. Receptors detect change

  2. Coordination centres interpret change and send signals

  3. Effectors carry out response to return levels to normal
• Levels get too low


  Automatic control systems bring them back up to normal through negative feedback
• Levels get too high

  Automatic control systems bring them back down to normal through negative feedback
• • The nervous system sends fast, precise electrical impulses
  • The endocrine system uses slower, longer-lasting hormones