Role of Negative Feedback

• Negative Feedback: A corrective mechanism that responds to a change in the environment by reducing the change
• What does Thyroxine do?


  Stimulates the basal metabolic rate, helping with growth
• How is thyroxine controlled?


  • As thyroxine levels increase, TSH levels decrease
  • As thyroxine levels decrease, TSH levels increase

  CONTROLLED BY NEGATIVE FEEDBACK
• TSH (Thyroxine Stimulating Hormone): Stimulates thyroid to secrete thyroxine
• When is adrenaline secreted from adrenal glands?


  When in danger or in fear to stimulate a person's "Fight or Flight"
• What does Adrenaline do to a person?

  • Heart and breathing rate increases
  • Glycogen is converted into glucose for respiration
  • Blood diverted from digestive system to muscles
  • Pupils dilate to allow more light to enter
  • Mental awareness increases
• Adrenaline boosts the delivery of oxygen and glucose to muscles
• Adrenaline is not controlled by Negative Feedback as it is responds to danger