alimentary canal (digestive tract; gut) A tubular organ in animals that is divided into a series of zones specialized for the ingestion, digestion, and absorption of food and for the elimination of indigestible material (see illustration). In most animals the canal has two openings, the mouth (for the intake of food) and the anus (for the elimination of waste). Simple animals, such as cnidarians (e.g. Hydra and jellyfish) and flatworms, have only one opening to their alimentary canal, which must serve both functions.

alimentary canal Digestive tract of an animal that begins with the mouth, continues through the oesophagus to the stomach and intestines, and ends at the anus. It is about 9m (30ft) long in humans. See also digestive system

alimentary canal In animals, a tube along which food passes and through parts of whose walls nutrients are absorbed into the body. In some animals (e.g. coelenterates) the canal has a single opening. In most animals it has two: a mouth through which food enters; and an anus through which unabsorbed material leaves the body.

alimentary canal See gastro‐intestinal tract.

alimentary canal (ali-ment-er-i) n. the long passage, extending from the mouth to the anus, through which food passes to be digested and absorbed.