Small intestines....

The small intestine begins at the pyloric sphincter and and ends with its connection to the large intestine at the ileocaecal valve

DUODENUM

• The duodenum receives partly-digested food and acid from the stomach. This acid is quickly neutralised in the alkaline environment of the duodenum.
• The duodenum also receives bile from the gallbladder that breakdown fats, the pancreas makes pancreatic juice that digest carbohydrates, fats and protein. The intestine walls also produces a juice that contain enzymes like amylase, protease, lipase.
• Glands produce mucus to help ease passage of the undigested food.
• The digestion takes place in the duodenum before the material travels further into the small intestine.

JEJUNUM and ILEUM

The walls of the jejunum and ileum contain mini finger-like bumps called 'villi', on the villi there is also more finger like bumps known as micro-villi, this is even smaller than the villi ,this increased surface area improves the small intestine's ability to absorb nutrients,the villi absorb the nutrients and transfer them to the bloodstream and the liver.The final stage of digestion is completed in this part of the small intestine, where food and liquid are broken down into nutrient components.