Human embryology is the study of the development of an embryo that occurs during first eight weeks after fertilization.
It is the time from fertilization through the development of the early embryo until implantation is completed in the uterus. It takes around 10 days.
The zygote divides mitotically.
Blastomeres are the undifferentiated dividing cells, that aggregate into a sphere enclosed within the membrane of the ovum.
Gap junctions develop.
16 celled stage is the Morula.
Development is holoblastic.
Cells differentiate into an outer layer called as trophoblast & inner cellular mass.
Inner mass of cells differentiates to form embryoblast & it polarizes at one end leaving a cavity called as blastocoel. This forms the blastocyst.
Embryoblast will become the embryo & the trophoblast will become the placenta.
The trophoblast allows the blastocyst to attach to the endometrium, where it will implant.