In utero, the blastocyst implants and all three embryonic germ layers are formed during gastrulation. Somatic stem cells are present in many fetal and post-natal tissues. Somatic stem cells are ...
The outer membrane (chorion) and trophoblast layer of the placenta are derived from the trophoectoderm of the blastocyst cells. Other extra-embryonic tissues, including the amnion (inner membrane ...