# Describe how the human body's physical defences prevent pathogens from entering the body.

> WJEC GCSE Biology (Wales) — 2.6.1 Pathogens and disease · Describe · 4 marks

## Mark scheme (4 marks)

1. The skin acts as a physical barrier that prevents pathogens from entering the body
2. Mucus in the airways/respiratory tract traps pathogens
3. Cilia sweep mucus (containing trapped pathogens) away from the lungs / towards the throat
4. Stomach acid kills pathogens that are swallowed

## Key terms

- [pathogen](https://www.gradenine.co.uk/glossary/pathogen)
- [physical defence](https://www.gradenine.co.uk/glossary/physical-defence)

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-the-human-body-s-physical-72c7cf1a) · Published by Druglandscape Ltd.