What is Alimentary canal?
[[File:Alimentary Canal (PSF).jpg|thumb|Gastrointestinal tract]] '''Alimentary canal''' is the term used in [[zoology]] for the gut of [[vertebrates]]. For humans in particular, see [[digestive system]]. The canal (or tube) carries food through [[digestion]] and [[excretion]].<ref name=Invert/> Into the tube come various digestive [[enzyme]]s. [[Gut flora]] help digestion, and the production of vitamins. Muscular movements pass the material down the tube. The gut usually has an exit, the [[anus]], by which the animal disposes of solid wastes. Some small animals have no anus and dispose of solid wastes by other means, for example through the mouth.<ref name=Invert>Ruppert E.E., Fox R.S. and Barnes R.D. 2004. ''Invertebrate zoology''. 7th ed, Brooks/Cole. {{ISBN|0030259827}}</ref> == Evolutionary history == The gut evolved at least twice, an example of [[convergent evolution]]. [[Protostome]]s develop their mouths first, while [[deuterostome]]s develop their mouths second. Protostome include [[arthropod]]s, [[mollusc]]s, and [[annelid]]s, and deuterostomes include [[echinoderm]]s and [[chordate]]s, including humans. ==References== {{reflist}} {{biology-stub}} [[Category:Anatomy of the digestive system]] [[Category:Animal anatomy]]