# Explain why the walls of arteries are thicker and more muscular than the walls of veins.

> Pearson Edexcel International GCSE Biology (4BI1) — 2.11 Transport: humans · Explain · 4 marks

> Blood is transported around the body through a network of blood vessels. Arteries carry blood away from the heart, whilst veins carry blood back towards the heart.

## Mark scheme (4 marks)

1. Blood in arteries is at higher pressure (than in veins)
2. Thick muscular walls withstand / prevent bursting due to the high pressure
3. Blood in veins is at lower pressure (than in arteries)
4. Thinner walls are sufficient because veins do not need to withstand high pressure

## Key terms

- [arteries](https://www.gradenine.co.uk/glossary/arteries)
- [veins](https://www.gradenine.co.uk/glossary/veins)

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](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-why-the-walls-of-arteries-35343193) · Published by Druglandscape Ltd.