(Science: anatomy, gastroenterology) The small intestine is composed of three sections: duodenum, jejunum and ileum.
All are involved in the absorption of nutrients. The total length of the small intestine is approximately 22 feet. The longest part of the alimentary canal; where digestion is completed.A tube like structure that can be over 6 metres long in a grown adult that forms part of the digestive system. The small intestine is the site where most food is absorbed in an organism, where digestive enzymes are secreted into it to further break down f.