The small intestine (or small bowel) is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. The small intestine is composed of a duodenum,jejunum, and ileum. It receives bile juice and pancreatic juice through the hepatopancreatic duct, controlled by Sphincter of oddi. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to describe the entire intestine. This article is primarily about the human gut, though the information about its processes is directly applicable to most placental mammals. The primary function of the small intestine is the absorption of nutrients and minerals found in food. (A major exception to this is cows; for information about digestion in cows and other similar mammals, see ruminants and platypus.