negative feedback response

• Negative feedback


  A process that reverses a change in the internal environment to return it to the optimum point
• Mechanism of negative feedback

  1. Receptors detect change from optimum

  2. Receptors signal coordinators

  3. Coordinators decide appropriate response

  4. Coordinators signal effectors

  5. Effectors carry out action to reverse change
• Optimum point


  The ideal value for factors like pH, temperature, water potential that the body tries to maintain
• Temperature increases


  Body mechanisms work to lower temperature back to optimum
• Temperature decreases


  Body mechanisms work to raise temperature back to optimum
• Receptors


  Detect changes in internal conditions and send signals to coordinators
• Coordinators


  Analyse signals from receptors and decide appropriate response, then signal effectors
• Effectors


  Carry out actions to reverse changes and return internal conditions to optimum
• Coordinators use information from multiple receptors (e.g. skin and hypothalamus) to determine appropriate response
• Positive feedback


  A process that reinforces a change away from the optimum, leading to large unstable changes
• Positive feedback is useful for action potentials in neurons to allow rapid depolarization
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