B11.4 - The Role Of Negative Feedback (Finished)

Question 1

What are negative feedback mechanisms?

Answer 1

Negative feedback mechanisms are mechanisms used by your automatic control system to keep your internal environment stable

Question 2

How does negative feedback work in summary?

Answer 2

If a factor increases changes take place to reduce it to the original level. If a factor decreases, changes take place to increase it to the original level

Question 3

What does the thyroid produce?

Answer 3

Thyroxine

Question 4

What is thyroxine used for?

Answer 4

Controlling the basal metabolic rate of your body

Question 5

What is the metabolic rate?

Answer 5

How quickly substances are broken down, oxygen is used up, how the brain grows/develops

Question 6

How are thyroxine levels in the blood kept stable?

Answer 6

Negative feedback. If thyroxine levels rise sensors in the brain detect it and the pituitary releases less TSH, so they return to normal. If they fall sensors detect it and the pituitary gland releases more TSH so they return to normal

Question 7

What does adrenaline cause? (2 things)

Answer 7

• Your heart rate and breathing to increase
• stored glycogen to be converted and released by the liver
• your mental awareness to increase
• the pupils of your eyes to dilate to let in more light
• blood to be diverted to big muscles

Question 8

Does adrenaline release involve negative feedback?

Answer 8

No

Question 9

How are adrenaline levels controlled?

Answer 9

Adrenaline is released by the adrenal glands when needed and stops being released when not needed so the levels return to normal (no adrenaline)

Question 10

Why do conditions inside the body need to be kept steady?

Answer 10

Your cells need the right conditions to function properly, including right conditions for enzyme action

Question 11

What does TSH stand for?

Answer 11

Thyroid Stimulating Hormone