# Adrenaline is a hormone released during the 'fight-or-flight' response. Explain how adrenaline reaches its target organs from the adrenal gland, and describe two ways in which adrenaline prepares the body for action.

> Eduqas A-Level Biology — 4.2 Inheritance · Explain · 5 marks

## Mark scheme (5 marks)

1. Adrenaline is released / secreted by the adrenal gland into the bloodstream
2. Adrenaline travels in the blood to target organs
3. Adrenaline binds to receptors on the surface of target organ cells
4. Adrenaline increases heart rate / pulse rate (to deliver more oxygen to muscles)
5. Adrenaline causes glycogen to be converted to glucose / increases blood glucose levels (to provide energy for respiration)

## Key terms

- [adrenaline](https://www.gradenine.co.uk/glossary/adrenaline)
- [adrenal gland](https://www.gradenine.co.uk/glossary/adrenal-gland)
- [target organs](https://www.gradenine.co.uk/glossary/target-organs)
- [hormone](https://www.gradenine.co.uk/glossary/hormone)

## Related

- [Revision notes for Eduqas A-Level Biology](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/adrenaline-is-a-hormone-released-during-005ae074) · Published by Druglandscape Ltd.