B3.2.2 Negative Feedback

Question 1

What does Thyroxine do?

Answer 1

Regulates metabolic rate

Question 2

what does thyroid gland do?

Answer 2

Take iodine (found in many foods) and convert it into thyroxine by combining amino acids and tyrosine

Question 3

What do adrenal glands do?

Answer 3

Secrete adreneline in times of stress to prepare body for intensive action.

Question 4

What is negative feedback?

Answer 4

Way to keep internal conditions of animals constant inside animal.
Used in homeostasis.

Question 5

What does negative feedback do?

Answer 5

A small change in one direction is detected by sensory receptors. Therefore effectors work to reverse change and restore conditions to base levels.

Question 6

How are thyroxine levels controlled using negative feedback?

Answer 6

Thyroid stops producing thyroxine
—> hypothalamus detects cells need more energy
—>pituary glands release TSH
—>thyroid produces thyroxine
—>hypothalamus detects cells have enough energy
—>pituary stops producing TSH—>AGAIN

Question 7

How are adrenaline levels controlled?

Answer 7

When you feel threatened or scared brain sends signal to adrenal glands to secrete adrenaline, body responds by:
-respiring quicker to increase ATP production
-increase rate of breathing to cope with extra demand for oxygen
-increase heart rate
-diverts blood away from areas such as digestive system towards muscles
_when stress is removed signals sent toi adrenal glands to stop & affected body systems return to previous state