The connecting stalk, also known as the primitive streak, is a critical structure in the early embryonic development of vertebrates, including humans.
The Extraembryonic mesoderm is a specialized type of mesoderm that develops outside of the embryo itself during embryogenesis. It plays crucial roles in supporting the developing embryo and facilitating its interaction with the maternal tissues. Extraembryonic mesoderm arises during gastrulation, the process by which the three primary germ layers—ectoderm, mesoderm, and endoderm—are established.
Here are some key points about extraembryonic mesoderm:
Formation: Extraembryonic mesoderm originates from mesodermal cells that migrate away from the primitive streak during gastrulation. These cells move towards the outer layer of the embryo, where they contribute to the formation of extraembryonic tissues.