intraembryonic mesoderm

This layer of cells becomes know as intraembryonic mesoderm.

The more inferior portion of the primitive streak will still have epiblast cells ingressing to make intraembryonic mesoderm, while the more superior portion has stop ingressing.

After the definitive endoderm and intraembryonic mesoderm formations are complete, the remaining epiblast cells do not ingress through the primitive streak; rather they remain on the outside and form the ectoderm.

After the cells have moved bilaterally from the primitive streak and matured, four divisions of intraembryonic mesoderm are made; cardiogenic mesoderm, paraxial mesoderm, intermediate mesoderm and lateral plate mesoderm.