Small intestine anatomy in 3D
The small intestine is the long tube between the stomach and the large intestine, running through the duodenum, jejunum and ileum. Most digestion and nutrient absorption happen here. The duodenum curves in a C around the head of the pancreas and is mostly fixed behind the peritoneum, while the jejunum and ileum hang from the mesentery and can move within the abdomen. The jejunum lies mainly in the upper left and the ileum in the lower right, and the ileum joins the caecum of the large intestine at the ileocaecal valve. Its inner wall carries circular folds and villi.
Frequently asked questions
Where is the small intestine?
The small intestine is the long tube between the stomach and the large intestine, running through the duodenum, jejunum and ileum.
What does the small intestine do?
Most digestion and nutrient absorption happen in the small intestine.
Which body system does the small intestine belong to?
The small intestine belongs to the digestive system. The digestive system is made up of the digestive tract running from mouth to anus (oesophagus, stomach, small and large intestine) and the liver, gallbladder and pancreas, which make digestive juices and send them into the tract.
Where do the small and large intestines meet?
In the lower right of the abdomen, where the end of the ileum passes through the ileocaecal valve into the caecum, the first part of the large intestine.
Parts of the small intestine
- Duodenum: The first part of the small intestine, right after the stomach, where pancreatic juice and bile enter.
- Jejunum: The middle stretch of the small intestine, busy absorbing nutrients.
- Ileum: The last part of the small intestine, joining the large intestine.
Other organs
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Related reading
Once the 3D model loads you can turn it and select each part.