Thyroxine

• What does the thyroid gland produce?


  Thyroxine
• What is thyroxine?


  A hormone released from the thyroid gland that controls the metabolic rate of the body
• What does thyroxine do?


  -increases the metabolic rate

  -controls growth and development in young animals
• What is thyroxine controlled by?


  By negative feedback
• What does thyroxine control?


  the speed at which oxygen and food products react to release energy for the body to use
• How are thyroxine levels controlled?


  By negative feedback
• What are the two glands involved in controlling thyroxine levels?

  The hypothalamus and pituitary gland
• What happens when thyroxine levels are low in the bloodstream?


  The hypothalamus releases TRH, stimulating the pituitary to release TSH, which increases thyroxine release from the thyroid
• How do normal thyroxine levels affect TRH and TSH release?


  Normal levels inhibit TRH release from the hypothalamus, which in turn inhibits TSH release from the pituitary
• What is the role of the hypothalamus and pituitary gland in regulating thyroxine levels?


  • Hypothalamus detects low thyroxine levels
  • Releases TRH to stimulate pituitary
  • Pituitary releases TSH to increase thyroxine from the thyroid
  • Normal levels inhibit TRH and TSH release
• Where is the thyroid gland?


  neck