IGCSE Biology glossary
Villus
Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Definition
A tiny finger-like projection on the inner lining of the small intestine that increases the surface area for absorption of digested food. Each villus has a thin epithelium, a dense network of blood capillaries and a central lacteal.
What to include in an exam answer
The plural is 'villi'. In adaptation questions, list: large surface area (many villi), thin walls (one cell thick for short diffusion distance), rich blood supply (maintains concentration gradient), and lacteal (absorbs fatty acids and glycerol).
Example in context
Explain three ways in which a villus is adapted for efficient absorption (3 marks): Many villi increase the surface area; the epithelium is only one cell thick, providing a short diffusion distance; a rich blood supply maintains the concentration gradient for absorption.
Related syllabus topic
Human nutrition