Blastosphere (Noun)
Meaning
Early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs.
Classification
Nouns denoting animals.
Examples
- The blastosphere forms during the early stages of embryonic development, roughly five to eight days after fertilization, when the embryo undergoes a series of cell divisions without significant growth.
- A characteristic feature of the blastosphere is its hollow cavity, the blastocoel, which separates the inner cell mass from the trophoblast layer that surrounds it.
- By the time the embryo reaches the blastosphere stage, it has typically entered the uterine cavity, ready for implantation.
- Formation of the blastosphere requires successful cleavage of the zygote and morula stages of development, followed by a reorganization of the embryo into the blastocyst form.
- Upon formation, the blastosphere stage typically lasts a few days, culminating in the beginning of implantation, which firmly anchors the embryo in the uterine wall for continued growth.