# A student is sitting in a classroom when a loud noise suddenly causes them to blink. Explain how the nervous system coordinates this response, naming the types of neurones involved.

> Eduqas A-Level Biology — 3.8 The nervous system · Explain · 5 marks

> The blink response is an automatic reaction to a sudden stimulus. It involves the nervous system detecting the stimulus and sending signals to the muscles around the eye.

## Mark scheme (5 marks)

1. The sound is detected by a receptor (in the ear / sensory receptor)
2. A sensory neurone carries the impulse from the receptor to the central nervous system (brain or spinal cord)
3. The central nervous system (brain) processes/coordinates the information
4. A motor neurone carries the impulse from the CNS to the effector (muscle around the eye)
5. The effector (muscle around the eye) contracts, causing the eye to blink

## 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/a-student-is-sitting-in-a-7ffb8ec1) · Published by Druglandscape Ltd.