# Explain how the small intestine is adapted to absorb the products of digestion efficiently.

> AQA A-Level Biology (7402) — 3.3.3 Digestion and Absorption · Explain · 5 marks

## Mark scheme (5 marks)

1. The small intestine has villi (finger-like projections) on its inner wall
2. Villi increase the surface area (for absorption)
3. Villi have a rich / dense blood supply (capillary network) to maintain a concentration gradient / carry absorbed molecules away quickly
4. Villi have a thin wall / epithelium (one cell thick) so the distance for diffusion is short
5. Villi contain lacteals to absorb fatty acids and glycerol (lipids / fats) into the lymphatic system

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