Adrenaline and Thyroxine

Question 1

What does adrenaline do?

Answer 1

Prepares the body for either fight or flight.

Question 2

What does adrenaline do to the heart?

Answer 2

• Binds to specific receptors in the heart.

- Causes the heart muscle to contract more frequently with more force.

Question 3

What is the result of adrenaline acting on the heart?

Answer 3

• Heart rate and blood pressure increase.

- Increases blood flow to muscles.

Question 4

What does adrenaline do to the liver?

Answer 4

• Binds to receptors in the liver.

- Causes the liver to break down its glycogen stores to release glucose.

Question 5

What is the result of adrenaline acting on the liver?

Answer 5

Increases the blood glucose level, so there’s more glucose in the blood to be transported to cells.

Question 6

What does thyroxine do?

Answer 6

Regulates the metabolic rate.

Question 7

What is the metabolic rate?

Answer 7

The speed at which chemical reactions in the body occur.

Question 8

What is the response for when thyroxine levels are too low?

Answer 8

• Hypothalamus releases TRH.
• TRH stimulates the pituitary gland to release TSH.
• TSH stimulates the thyroid gland to release thyroxine.

Question 9

What is the response for when thyroxine levels are too high?

Answer 9

• Release of TRH from the hypothalamus is inhibited.
• Reduces production of TSH.
• Blood thyroxine level falls.