Adrenaline is a hormone released during the 'fight-or-flight' response. Describe the role of adrenaline in preparing the body for a fight-or-flight response, including where it is produced and the effects it has on the body.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
A student is walking alone at night and suddenly hears a loud, unexpected noise behind them. Their heart begins to race and they feel a surge of energy.
Model answer (5 marks)
Adrenaline is produced by the adrenal glands.
It is released into the bloodstream and carried to target organs.
It increases heart rate and pulse rate.
It increases blood flow to the muscles and raises breathing rate.
It causes glycogen to be converted into glucose, raising blood sugar levels and providing more glucose for respiration.
It is released into the bloodstream and carried to target organs.
It increases heart rate and pulse rate.
It increases blood flow to the muscles and raises breathing rate.
It causes glycogen to be converted into glucose, raising blood sugar levels and providing more glucose for respiration.
Examiner tips
- Use the exact terms: adrenal glands, bloodstream, target organs, heart rate, pulse rate, blood flow to muscles, breathing rate, glycogen conversion, glucose.
- Structure answer in five clear points matching the mark scheme.
- Include the physiological pathway (release, transport, effect).
Common mistakes
- Confusing adrenaline with cortisol or omitting the adrenal gland as the source.
- Not specifying that adrenaline acts via the bloodstream to reach target organs.
- Mixing up heart rate with blood pressure or forgetting the glycogen‑glucose conversion.
Mark scheme (5 marks)
- Adrenaline is produced / released by the adrenal gland
- Adrenaline is released into / travels in the bloodstream to target organs
- Adrenaline increases heart rate / pulse rate
- Adrenaline increases blood flow to muscles / increases breathing rate
- Adrenaline causes glycogen to be converted into glucose, increasing blood sugar levels / providing more glucose for respiration
Key terms in this question
adrenaline · fight-or-flight response
Related
- All WJEC A-Level Biology (Wales) revision notes →
- How to answer a "Describe" question →
- Decode the mark scheme abbreviations →
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