Contents
Key Stage 2
Meaning
The small intestine is part of the digestive system.
Key Stage 3
Meaning
The small intestine is an organ in the digestive system which absorbs nutrients into the blood.
About The Small Intestine
- The small intestine is a very long tube to give a large surface area to absorb nutrients.
- There is around 1kg of bacteria inside the small intestine which helps digest the food.
- There are digestive enzymes in the small intestine which break down large molecules into smaller molecules.
- Only small molecules can be absorbed into the blood through the wall of the small intestine.
Key Stage 4
Meaning
The small intestine is an organ in the digestive system which absorbs nutrients into the blood.
About The Small Intestine
- The Small Intestine is where food is broken down by digestive enzymes including amylase, protease and lipase before being absorbed into the blood.
- The Small Intestine is long and folded to increase the surface area.
- The Small Intestine has structures called Villi which are extra folds in the surface to increase the surface area.
- The blood supply to the villis in the Small Intestine is very good to constantly supply blood with little nutrients keeping a high concentration gradient between the food and the blood.
- There is around 1kg of bacteria inside the small intestine which helps digest the food.
- Only small molecules can be absorbed into the blood through the wall of the small intestine.