epiblast

The upper one is now covered only by the epiblast.

In general, all germ layers will derive from the epiblast.

The floor of the amniotic cavity is formed by the epiblast.

The epiblast layer is derived from the inner cell mass.

The epiblast keeps moving and forms a second layer, the mesoderm.

The epiblast is the outer layer that consists of columnar cells.

This process begins with formation of a primitive streak on the surface of the epiblast.

It lies beneath the epiblast and consists of small cuboidal cells.

These cells are also derived from epiblast which is transformed into ectoderm.

It can be dissected into two principal layers, the epiblast and the hypoblast.

The inner cell mass initially has two layers: the hypoblast and epiblast.

Underlying the epiblast, is the hypoblast, where the extra-embryonic tissue originates.

Subsequently, the pro-amniotic cavity forms in the epiblast and enlarges to extend into the extra-embryonic region.

The formation of the primitive streak involves the coordinated movement and re-arrangement of cells in the epiblast.

The cells of the epiblast move toward the primitive streak and slip beneath it in a process called invagination.

The ectoderm generates the outer layer of the embryo, and it forms from the embryo's epiblast.

The cardiogenic field appears the halfway through the third week of embryo development, with progenitor cells appearing in the epiblast.

In the mouse embryo, the egg forms a cylinder with the epiblast forming a cup at the distal end of that cylinder.

This is lined by the amnionic membrane, with cells that come from the epiblast (called amnioblasts).

It is derived from the epiblast layer, which lies between the hypoblast layer and the amnion.

Only during or after epiblast diversification can experimental interference preferentially modify or distinguish particular fetal tissues (2).

At the embryonic pole of the blastocyst, the amniotic cavity finds a home between the epiblast and the hypoblast.

These three layers arise early in the third week (after gastrulation) from the epiblast (a portion of the mammalian inner cell mass).

The epiblast, now called primitive ectoderm will perform gastrulation, approximately at day 16 (week 3) after fertilization.

Epiblast migrates between the epiblastic disc and trophoblast.