- Archenteron
The primitive gut that forms during
gastrulation in the developingblastula is known as the archenteron. It develops into the digestive tract of an animal.Formation of the Archenteron
[See
Gastrulation ]As
mesenchyme cells detach from thevegetal pole in the blastula and enter the fluid filled cavity in the center (theblastocoel ), the remaining cells at the vegetal pole flatten to form avegetal plate . This buckles inwards towards the blastocoel in a process calledinvagination . The cells continue to be rearranged until the shallow dip formed by invagination transforms into a deeper, narrower pouch formed by thegastrula 'sendoderm . The open end of the archenteron is called theblastopore .The
filopodia --thin fibers formed by the mesenchyme cells--found in a late gastrula contract to drag the tip of the archeteron across the blastocoel. The endoderm of the archenteron will fuse with theectoderm of the blastocoel wall. At this point gastrulation is complete, and the gastrula has a functional digestive tube.The indentation that is actually formed is called the "
blastopore lip" inamphibian s andfish , and the "primitive streak" inbird s andmammal s. Each is controlled by the dorsal blastopore, and primitive node, respectively.External links
* [http://chsweb.lr.k12.nj.us/mstanley/outlines/animals/antax/image51.gifDiagram]
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