During the Pre-embryonic Period, what is the fertilized ovum referred to once it reaches the uterus?

During the Pre-embryonic Period, the fertilized ovum is referred to as a blastocyst once it reaches the uterus. After fertilization, the zygote begins its journey through the fallopian tube, where it undergoes several divisions, transforming from a zygote into a morula—a solid ball of cells. The morula then develops into a blastocyst as it approaches implantation in the uterine lining. The blastocyst consists of an outer layer of cells called the trophoblast, which will eventually contribute to the placenta, and an inner cell mass that will develop into the embryo.

This stage is critical in early pregnancy because successful implantation of the blastocyst in the uterus is essential for establishing pregnancy. An understanding of this terminology and the developmental stages leading to implantation is crucial, as it lays the foundation for comprehending subsequent stages of embryonic development.