text: The small intestine or small bowel is an organ in the gastrointestinal tract where most of the absorption of nutrients from food takes place.  It lies between the stomach and large intestine, and receives bile and pancreatic juice through the pancreatic duct to aid in digestion. The small intestine is about  long and folds many times to fit in the abdomen. Although it is longer than the large intestine, it is called the small intestine because it is narrower in diameter.
  The small intestine has three distinct regions – the duodenum, jejunum, and ileum. The duodenum, the shortest, is where preparation for absorption through small finger-like protrusions called villi begins. The jejunum is specialized for the absorption through its lining by enterocytes: small nutrient particles which have been previously digested by enzymes in the duodenum.  The main function of the ileum is to absorb vitamin B12, bile salts, and whatever products of digestion that were not absorbed by the jejunum.
  Structure
  Size
  The length of the small intestine can vary greatly, from as short as  to as long as , also depending on the measuring technique used. The typical length in a living person is . The length depends both on how tall the person is and how the length is measured. Taller people generally have a longer small intestine and measurements are generally longer after death and when the bowel is empty.