Enterocoely

Enterocoely is a process by which a mesoderm is formed in a developing embryo, in which the coelom forms from pouches "pinched" off of the digestive tract (also known as the embryonic gut, or archenteron). This type of coelom formation occurs in deuterostome animals.

Enterocoelous development begins once the embryo reaches the gastrula phase of development. At this point, there are two layers of cells - the ectoderm (outermost) and the endoderm (innermost) layers. The mesoderm (middle layer) begins to form as two "pockets" of tissue (one above the endoderm, and one below) are formed via folding of the endoderm. These "pockets" begin to grow larger, and as they do so, they extend towards each other. When the two "pockets" of cells meet, the mesoderm is formed - a complete layer of tissue right inbetween the endoderm and ectoderm layers.

This then leads to the formation of a coelom.

In protostomes, the body cavity is formed by schizocoely.