The |small intestine| is descriptively divided into three sections: the |duodenum|, the ileum, and the |jejunum|. The |duodenum| accepts the digested food paste, called ~chyme~, from the |stomach|, through the |pylorus| sphincter. The |duodenum| is about ten inches long and forms a curve around the head of the |pancreas|. The |duodenum| secretes digestive ~enzymes~ invertase and erepsin, necessary for digestion. The gallbladder, |liver|, and |pancreas| also deposit ~enzymes~ and ~bile~ into the |duodenum|. The |jejunum| is the intermediate section of the |small intestine|, measuring between six and eight feet (a little over two meters) long. The |jejunum| carries digested food through the |small intestine| rapidly by peristalytic waves and, as a result, seldom has much food matter in it. It is connected to the |abdominal wall| by the mesentary. The ileum is the last, and longest, segment of the |small intestine|, measuring up to 13 feet (4 meters) or longer. Most of the absorption of useful food nutrients takes place in the ileum before it empties out into the |cecum| of the |large intestine|.
