In early embryogenesis of most eutherian mammals, the<unk>  (abbreviated<unk>  and also known as the embryoblast or pluriblast (the latter term being applicable to all mammals)) is the<unk>  of<unk> s inside the primordial embryo that will eventually give rise to the definitive structures of the fetus. This structure forms in the earliest steps of development, before implantation into the endometrium of the uterus has occurred. The<unk>  lies within the blastocoele (more correctly termed "blastocyst cavity", as it is not strictly homologous to the blastocoele of anamniote vertebrates) and is entirely surrounded by the single layer of<unk> s called trophoblast.
Inner cell mass
Hair follicle
Growth cone
Hertwig's epithelial root sheath
Articular processes
Junctional epithelium
Adnexa
Granulation tissue