# Describe how a nerve impulse travels from a receptor to an effector in a simple reflex arc.

> Eduqas GCSE Biology — 4.1 Nervous coordination and control in humans · Describe · 4 marks

## Mark scheme (4 marks)

1. Receptor detects a stimulus
2. Impulse travels along a sensory neurone to the spinal cord / relay neurone
3. Impulse passes across a synapse / from one neurone to the next
4. Motor neurone carries impulse to the effector, which responds

## Key terms

- [receptor](https://www.gradenine.co.uk/glossary/receptor)
- [effector](https://www.gradenine.co.uk/glossary/effector)

## Related

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

---
Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-a-nerve-impulse-travels-22093365) · Published by Druglandscape Ltd.