How can the morphology of embryo be explained

Question

After the neurula phase and from its ventral part to the dorsal how can the morphology of embryo be explained?

Answer 1

In a schematic longitudinal part of the embryo after the neurula phase, the outermost layer of cells is Ectoderm.  In the central areas comes the archenteron tube formed of endodermal cells. In both parts of embryo coeloms delimited by mesoderm are present. In the central area above the archenteron and in the center of the coeloms there is notochord. In the dorsal area just on top of the notochord lies the neural tube.