In this video lecture, educator describes three stages of embryology as initial stage, embryonic and fetal stage. Several stages occur during human development in uterus including fertilization, cleavage, blastulation, compaction, cavitation, implantation, differentiation and disc formation.
Fertilization is where male and female gametes combine to form embryo. Cleavage is successive rapid mitotic divisions with constant cytoplasm. Then cell divides by process of blastulation, compaction and cavitation.
Progesteron secreted by corpus luteum prepares the endometrium for implantation. 7th day of development is called gastrulation and it happens concurrently with implantation. After this there is germ layer formation and formation of provisory organs. Neural plate combine to form neural crest.
Cell can be differentiated by ectoderm, mesoderm and endoderm. Educator describes the Hedgehog Pathway for cell signalling. Three axis are established during the development of embryo.