Adrenaline
Biology: AQA GCSE Higher, topic 5.3.4
Adrenaline
Adrenaline is a hormone secreted (discharged) by the adrenal glands. It has different functions:
Heart rate and blood pressure
- Adrenaline increases heart rate and blood pressure, and dilates the pupils in our eyes.
Lungs
- Adrenaline enlarges the air passages of the lungs and alters metabolism in order to boost the delivery of oxygen and glucose to the brain and the muscles.
Fight or flight
- In times of fear or stress, adrenaline is part of the so-called ‘fight or flight’ response, preparing the body to move and think quickly in response to danger.
Test yourself on Adrenaline
What structure secretes adrenaline in the body?
Why does adrenaline increase heart rate and blood pressure during times of stress?
Why does adrenaline dilate the pupils during a stressful or dangerous situation?
Why does adrenaline boost the delivery of oxygen and glucose to the brain and muscles during a dangerous situation?
If adrenaline did not enlarge the air passages or alter metabolism, what would most likely happen to the delivery of oxygen and glucose to the brain and muscles?