Adrenaline And Thyroxine

Question 1

what does adrenaline prepare you for

Answer 1

fight or flight response

Question 2

what is adrenaline

Answer 2

a hormone released by adrenal glands, which are just above the kidneys

Question 3

what is adrenaline released in response to

Answer 3

• stressful or scary situations
• your brain detects fear or stress and sends nervous impulses to adrenal glands
• respond by secreting adrenaline

Question 4

hoe does adrenaline prepare the body for a fight or flight response

Answer 4

by triggering mechanisms that increase the supply of oxygen and glucose to cells in the brain and muscles

Question 5

an example of what adrenaline does to the body

Answer 5

increase heart rate

Question 6

what can hormone release be affected by, in terms of interactions with other hormones

Answer 6

negative feedback

Question 7

how can your body control levels of hormones in the blood

Answer 7

by using negative feedback systems

Question 8

how does a negative feedback loop work

Answer 8

when the body detects the level of a substance is above or below the normal level, it triggers a response to bring the back to normal again

Question 9

what is thryroxine

Answer 9

a hormone released by the thyroid gland, which is in the neck

Question 10

what does thyroxine do

Answer 10

• it plays an important role in regulating the basal metabolic rate
• important for other processes in the body like stimulating protein synthesis for growth and development

Question 11

what is a basal metabolic rate

Answer 11

the speed at which chemical reactions in the body occur while the body is at rest

Question 12

what is thyroxine released in response to

Answer 12

thyroid stimulating hormone, which is released from the pituitary gland (TSH)

Question 13

how does a negative feedback system keep the amount of thyroxine in the blood at the right level

Answer 13

• level of thyroxine in the blood is higher than normal
• secretion of TSH from pituitary gland is inhibited
• this reduces amount of thyroxine released from the pituitary gland
• level in the blood falls back towards normal

Question 14

in a graph with blood thyrixone levels and time, explain what would happen if there was an increase of thyroxine levels and how the graph would look

Answer 14

• increase from normal detected
• release of TSH inhibited, causing decrease
• decrease from normal detected
• TSH released again, causing increase
• reaches normal level
• looks like a sine graph