Heuser's membrane
| Heuser's membrane | |
|---|---|
| Details | |
| Days | 12 |
| Gives rise to | extraembryonic coelom |
Heuser's membrane (or the exocoelomic membrane) is a short lived combination of hypoblast cells and extracellular matrix.
At day 9-10 of embryonic development, cells from the hypoblast begin to migrate to the embryonic pole, forming a layer of cells just beneath the cytotrophoblast, called Heuser's Membrane. It surrounds the exocoelomic cavity (primitive yolk sac), i.e. it lines the inner surface of the cytotrophoblast. At this point, the exocoelomic cavity replaces the blastocyst cavity.
At days 11 to 12, there is further delineation of the trophoblastic cells giving rise to a layer of loosely arranged cells that inserts between Heuser’s membrane and both syncytiotrophoblast and cytotrophoblast.
This article is issued from Wikipedia - version of the 1/10/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.