The first section of the small intestine is involved in digestion. The second section is involved in absorption.
Structure of Small Intestine
- It is approximately 6 metres long. This provides a large surface area for digestion and absorption
- Millions of glands release digestive enzymes into the small intestine.
- Millions of villi provide a huge surface area to aid the absorption of nutrients.
- The villi are one cell thick and have rich blood supply which allows nutrients to be absorbed into the bloodstream, by diffusion. This is where the digestive and circulatory systems interact.
- Digestion: The process of breaking down food into simpler molecules.
- Absorption: The process by which nutrients move from the digestive system to the bloodstream
- Villi: Tiny finger-like projections.