5.10 Adrenaline & Thyroxine

Question 1

When is adrenaline produced?

Answer 1

Adrenaline is produced during the ‘fight or flight’ response, when you get scared, stressed, or need to exercise. It prepared the body for activity.

Question 2

What does adrenaline do? (4 - simplified)

Answer 2

1) Increases heart rate
2) Increases blood pressure
3) Increases blood flow to muscles
4) Increases blood sugar (glucose) levels by stimulating the liver to break glycogen down into glucose.

Question 3

Which organ is adrenaline released from?

Answer 3

Adrenal gland

Question 4

Adrenaline causes the conversion of which substances?

Answer 4

Glycogen -> glucose

Question 5

The hormone TSH is involved in the regulation of thyroxine levels. What does TSH stand for?

Answer 5

Thyroid stimulating hormone

Question 6

What type of feedback is involved in the regulation of thyroxine levels?

Answer 6

Negative feedback

Question 7

Describe what will happen when thyroxine levels are too high

Answer 7

If thyroxine levels are too high, the thyroxine will inhibit the pituitary gland from producing TSH. TSH stimulates the thyroid gland to produce thyroxine, so less TSH means that the thyroid gland won’t release as much thyroxine, and so overtime thyroxine levels in the blood fall back to normal. This is an example of negative feedback.