# Explain how the inflammatory response acts as a non-specific defence mechanism following tissue damage or infection.

> IB DP Biology Higher Level (2023 syllabus) — C3.2 Defence against disease · Explain · 4 marks

## Mark scheme (4 marks)

1. Mast cells / damaged cells release histamine in response to tissue damage or infection
2. Histamine causes vasodilation / increased blood flow to the infected area, resulting in redness and heat
3. Histamine increases capillary permeability, allowing fluid / plasma proteins to move into the tissue, causing swelling / oedema
4. Phagocytes / neutrophils are attracted to the site by chemokines / chemical signals and carry out phagocytosis of pathogens

## Key terms

- [inflammatory response](https://www.gradenine.co.uk/glossary/inflammatory-response)
- [non-specific defence](https://www.gradenine.co.uk/glossary/non-specific-defence)

## Related

- [Revision notes for IB DP Biology Higher Level (2023 syllabus)](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/explain-how-the-inflammatory-response-acts-49fb452e) · Published by Druglandscape Ltd.