# Explain how the inflammatory response acts as a defence against infection at a site of tissue damage.

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

## Mark scheme (4 marks)

1. Damaged cells / mast cells release histamine (or other signalling chemicals / cytokines)
2. Histamine causes vasodilation / increased blood flow to the affected area, bringing more immune cells and plasma to the site
3. Phagocytes (neutrophils / macrophages) are attracted to the site by chemotaxis and engulf pathogens by phagocytosis
4. The response limits the spread of infection / contains pathogens locally, preventing systemic spread

## Key terms

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

## Related

- [Revision notes for IB DP Biology Standard 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-2a08666a) · Published by Druglandscape Ltd.