Thyroxine

• What is negative feedback?

  Negative feedback systems work to maintain a steady state. If a factor in the internal environment increases, changes Take place to deduct it and restore the or level and vice versa if the factor decreases
• What is used from the diet to make thyroxine?

  Iodine
• What does thyroxine control?

  • metabolic rate
  • how much oxygen the tissue use
  • brain development in children
• What happens when the receptors in the brain detect change change in the blood thyroxine levels rising?

  The pituitary gland releases less thyroxine stimulating hormone, so the thyroid produces less thyroxine
• What happens when the receptors in the brain detect change in the blood thyroxine levels falling?

  The pituitary gland releases more thyroxine stimulating hormone, so the thyroid produces more

  thyroxine