Apposition

Establishing a Loose Connection.

 

Apposition is the earliest contact between the blastocyst wall, the trophoblast and the endometrial epithelium.


This loose connection usually occurs between the crypt in the endometrium and the point in the blastocyst where the zona pellucida is ruptured most. Although ultimately the inner cell mass will be located closest to the deciduas layer by rotation within the blastocyst.

 

6 day old embryo implanting into endometrium 

 

Implantation image courtesy of Flickr under the creative commons licence: www.flickr.com/photos/lorelei-ranveig/2294096613/

Exciting News

Researchers have found a protein that helps implantation and sustains the embryo's existance as the protein helps to form blood vessels vital for growth.

See escience link on reference page for more information.