The blastomeres in the blastocyst are arranged into an outer layer called

The blastomeres in the blastocyst are arranged into an outer layer called trophoblast.

• Epiblast is primitive ectoderm. The epiblast is one of the two primary cell layers in the developing embryo. It gives rise to the three primary germ layers: ectoderm, mesoderm, and endoderm, which eventually differentiate into various tissues and organs in the body.
• Myoblast are mesodermal cells. Myoblasts are precursor cells that eventually give rise to muscle cells (myocytes). During development, myoblasts fuse together to form multinucleated muscle fibers, which are the functional units of skeletal muscle.
• Hypoblast is primitive endoderm. It is another layer of cells in the developing embryo, particularly in the blastocyst stage. It contributes to the formation of extraembryonic structures like the yolk sac, which plays a role in early nutrition and development.