Adrenaline and thyroxine

Question 1

What is adrenaline?

Answer 1

• Adrenaline is a hormones released by the adrenal gland, just above the kidneys

Question 2

When is adrenaline released?

Answer 2

• Its released in scary, stressful situations, your brain detects fear or stress and sends nervous impulses to the adrenal gland, which responds by secreting adrenaline

Question 3

How does adrenaline prepare your brain?

Answer 3

• it gets your brain ready for ‘fight or flight ‘ by triggering mechanism that increase the supply of 02 and glucose to cells in muscles and brain. example = increasing heart rate

Question 4

How does the body control levels of hormones in the blood?

Answer 4

• by using negative feedback systems.
• when body detects something is too high or below the normal level, it triggers off a response to bring it back to normal.

Question 5

What is Thyroxine?

Answer 5

A hormone released by the thyroid gland which is in the neck

Question 6

What role does thyroxine take in the body?

Answer 6

• important role in regulating basal metabolic rate - the speed in which chemicals react in the body while the body is at rest
• Important for loads of other processes in the body, such as stimulating protein synthesis for growth and development

Question 7

When is thyroxine released?

Answer 7

• In response to TSH, which is released from pituitary gland

Question 8

How do we keep amount of thyroxine in the blood at the right level?

Answer 8

• By the negative feedback system - level of Thyroxine in blood higher than normal, TSH secreted from pituitary gland is stopped. (VICE VERSA)
  This reduces amount of Thyroxine released from Thyroid gland so level of blood falls back to normal.