What is the main function of the small intestine?

The main function of the small intestine is to complete the digestion and absorption of nutrients. After food is partially digested in the stomach, it moves into the small intestine, where the majority of digestion occurs. Here, enzymes from the pancreas and bile from the liver further break down food into smaller molecules, such as amino acids, fatty acids, and simple sugars.

The walls of the small intestine are lined with tiny finger-like projections called villi, which increase the surface area for absorption. These villi contain blood vessels that transport absorbed nutrients into the bloodstream, allowing the body to utilize these essential components for energy, growth, and cell repair.

While the storage of faeces occurs in the large intestine, enzyme production primarily takes place in organs like the pancreas, and blood sugar regulation is managed by hormones such as insulin and glucagon produced by the pancreas, none of these functions are primarily associated with the small intestine.