4.5.3.7 Feedback Systems

Question 1

What is adrenaline produced by and when?

Answer 1

• adrenal glands
• times of fear or stress

Question 2

What does adrenaline do to the body?

Answer 2

• increase heart rate
• boosts delivery of oxygen and glucose to brain and muscles
• prepares body for ‘flight or fight’
• glycogen stored in liver converted to glucse
• pupils dilate to let more light in
• blood flow to muscles increased
• blood flow to digestive system decreased

Question 3

Where is thyroxine produced?

Answer 3

• thyroid gland

Question 4

What does thyroxine do to the body?

Answer 4

• stimulates basal metabolic rate
• plays an important role in growth and development

Question 5

What is the negative feedback system for thyroxine?

Answer 5

• when levels increase, it is detected by receptors
• inhibits release of TSH
• inhibits release of thyroxine so levels fall
• when levels decrease, it is detected by receptors
• stimulates hypothalamus to released TRH
• then releases TSH