Why is it important for the small intestine to have villi? How does their structure support their function?
Generated by claude-sonnet-4-6 · 2026-06-15 06:44 · grounding rag
Model Answer
Villi are important because the small intestine is the site of complete absorption of digested food, and a larger surface area allows more nutrients to be absorbed quickly and efficiently.
Structure supporting function:
- Villi are numerous finger-like projections on the inner lining of the small intestine.
- They greatly increase the surface area available for absorption.
- Each villus is richly supplied with blood vessels, which carry absorbed nutrients (glucose, amino acids, fatty acids, glycerol) to every cell of the body.
Without villi, the absorption of digested food would be far too slow to meet the body's needs.
Source: Chapter 5, Section 5.2.4 – Nutrition in Human Beings
---
Explanation
- The examiner expects two clear points: (1) increased surface area and (2) rich blood supply — both must be mentioned for full marks.
- "Finger-like projections" is the exact textbook phrase; use it.
- Avoid writing about digestion here — villi are only for absorption, not digestion.
- At 3 marks, one line on importance + two structural points is the ideal structure.