Editing Digestion (section)

===Gastrovascular cavity===
The [[gastrovascular cavity]] functions as a stomach in both digestion and the distribution of nutrients to all parts of the body.  Extracellular digestion takes place within this central cavity, which is lined with the gastrodermis, the internal layer of [[epithelium]]. This cavity has only one opening to the outside that functions as both a [[mouth]] and an [[anus]]: waste and undigested matter is excreted through the mouth/anus, which can be described as an incomplete [[gut (anatomy)|gut]].

In a plant such as the [[Venus flytrap]] that can make its own food through photosynthesis, it does not eat and digest its prey for the traditional objectives of harvesting energy and carbon, but mines prey primarily for essential nutrients (nitrogen and phosphorus in particular) that are in short supply in its boggy, acidic habitat.<ref name=Leege>{{cite web | url = http://www.sciam.com/article.cfm?id=how-does-the-venus-flytra | work = Scientific American | author = Leege, Lissa | title = How does the Venus flytrap digest flies? | access-date= 2008-08-20 }}</ref>

[[Image:Trophozoites of Entamoeba histolytica with ingested erythrocytes.JPG|thumb|125px|left|[[Trophozoites]] of ''Entamoeba histolytica'' with ingested erythrocytes]]