| Epiblast | |
|---|---|
 Human embryo at day 9. Epiblast (pink) is on top of the hypoblast (brown) | |
| Details | |
| Carnegie stage | 3 |
| Days | 8 |
| Precursor | Inner cell mass |
| Gives rise to | Ectoderm, mesoderm, endoderm |
| Identifiers | |
| Latin | epiblastus |
| TE | E5.0.2.2.1.0.1 |
| Anatomical terminology | |
In amniote embryonic development, the epiblast (also known as the primitive ectoderm) is one of two distinct cell layers arising from the inner cell mass in the mammalian blastocyst, or from the blastula in reptiles and birds, the other layer is the hypoblast. It drives the embryo proper through its differentiation into the three primary germ layers, ectoderm, mesoderm and endoderm, during gastrulation. The amniotic ectoderm and extraembryonic mesoderm also originate from the epiblast.
The other layer of the inner cell mass, the hypoblast, gives rise to the yolk sac, which in turn gives rise to the chorion.