Negative feedback

• What should you be able to explain by the end of the video?

  The roles of thyroxine and adrenaline
• What is the role of hormones in the body?

  They are chemicals released into the bloodstream
• Where are the adrenal glands located?

  At the top of the kidneys
• What hormone do the adrenal glands produce during stress?

  Adrenaline
• What is one main effect of adrenaline?

  Increases heart rate
• Why does the heart beat faster when adrenaline is released?

  To deliver more oxygen and glucose
• What is the purpose of oxygen and glucose in the body during stress?

  Needed for aerobic respiration
• What is the term used to describe the body's response to fear or stress?

  Fight or flight
• Where is the thyroid gland located?

  At the base of the neck
• What hormone does the thyroid gland release?

  Thyroxine
• What are the two main effects of thyroxine?

  Stimulates metabolic rate and growth
• What does metabolism refer to?

  The sum of all reactions in a cell
• How is the level of thyroxine in the blood controlled?

  By negative feedback
• What monitors the level of thyroxine in the blood?

  The brain
• What does the pituitary gland release when thyroxine levels fall?

  TSH (Thyroid Stimulating Hormone)
• What triggers the thyroid gland to release more thyroxine?

  TSH released by the pituitary gland
• What happens when the thyroxine level increases?

  It prevents the pituitary gland from releasing TSH
• What occurs when thyroxine levels become too high?

  Events are triggered to bring it back down
• What is a negative feedback cycle?

  • A process that maintains homeostasis
  • Involves monitoring a variable
  • Triggers responses to counteract changes
  • Example: Thyroxine regulation
• Where can you find questions on the adrenal glands and thyroid gland?

  In the vision workbook
• What is the purpose of the vision workbook mentioned?

  To provide questions on glands and feedback