Adrenaline
Biology: Edexcel IGCSE, topic 3.5.21
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
Which of these structures secretes adrenaline?