Ectoderm

After implantation of the blastocyst, embryonic cells divide further. At the end of week 2, three germ layers are formed. The ectoderm is the outermost layer of the early embryo: ectoderm – mesoderm – endoderm. The ectoderm will form skin, hair, nails, teeth, epithelium of mouth and nose, the peripheral nervous system, brain, motor neurons, retina and much more (Hill, 2020).