Absorption in the small intestine and colonSpec 7.5.1, 7.5.2
Absorption is the movement of nutrients from the intestines into the blood. The small intestine is the region where nutrients are absorbed, mostly in the ileum.
Water is also absorbed. Most water is absorbed from the small intestine, but some is also absorbed from the colon. What is left in the large intestine is the undigested food, which is stored in the rectum as faeces and removed by egestion.
| Region | What is absorbed |
|---|---|
| Small intestine | Nutrients (e.g. glucose, amino acids, fatty acids and glycerol, vitamins and mineral ions) and most of the water |
| Colon | Some water |
Exam tip:
If asked where water is absorbed, say 'mostly in the small intestine and some in the colon'. 'Colon only' loses the mark.