Adrenaline & Thyroxine

• Adrenaline is a hormone produced by the adrenal glands (sit on top of kidneys)
• When is adrenaline produced?

  During ‘Fight or Flight’ response, when you get scared, stressed, or need to exercise. It prepares the body for activity.
• What does adrenaline do?

  Increases heart rate.

  Increases blood pressure.

  Increases blood flow to muscles.

  Increases blood sugar (glucose) levels by stimulating the liver to break glycogen down into glucose.
• Which organ is adrenaline released from?

  Adrenal glands.
• What effect does adrenaline have on heart rate?

  Increases
• When is adrenaline released?

  Scared
• Adrenaline causes the conversion of which substance?

  Glycogen -> glucose
• Which organ is thyroxine released from?

  Thyroid gland (in the neck)
• What is the main role of thyroxine?

  To increase metabolic rate.

  Growth and development.
• Which organ is Thyroid Stimulating Hormone (TSH) released from?

  Pituitary gland.
• The hormone TSH is involved in the regulation of thyroxine levels.
• Does thyroxine stimulate or inhibit the pituitary gland from releasing TSH

  Inhibit
• Does TSH stimulate or inhibit the thyroid gland from releasing thyroxine?

  Stimulate
• Which type of feedback is involved in the regulation of thyroxine levels?

  Negative feedback
• Describe what will happen when thyroxine levels are too high..

  Thyroxine inhibits the pituitary gland from releasing TSH.

  Less TSH means the thyroid gland won’t release as much thyroxine.

  Thyroxine levels fall back to normal over time.

  Negative feedback.