Dictionary.net

the membrane that forms the wall of the blastocyst in early development; aids implantation in the uterine wall; "after implantation of the blastocyst in the uterine wall the trophoblast divides into two layers, the chorion and the placenta"

the membrane that forms the wall of the blastocyst in early development; aids implantation in the uterine wall; "after implantation of the blastocyst in the uterine wall the trophoblast divides into two layers, the chorion and the placenta"

The outer layer of cells of the blastocyst which works its way into the endometrium during ovum implantation and grows rapidly, later combining with mesoderm.

1. The characteristic tissue of the asexnal generation in the development of the organism. 2. An epiblastic layer which has no part in the development of the embryo, or the outer layer of cells enveloping the morula in the cystic stage.

The epiblastic layers lining the chorionic villi in the fetal placenta.

The epiblast of the blastocyst, in contradistinction to the epiblast of the germinal area, or the formative epiblast. [Gr.]