Chorion

Chorion is a thin, outer membranous sac in the early development of an embryo. It is composed of an extracellular matrix that is derived from both maternal and embryonic tissues, and is one of the major structures of a developing embryo. The chorion plays an important role in the protection, nutrition, gas and water exchange, and waste elimination of the embryo. It also helps in the embryo's attachment to the uterine wall and can act as a signaling molecule for the formation of blood vessels and other structures in the fetus. Furthermore, the chorion is essential for the successful implantation of the embryo and its further development, as well as its transition to the placenta. With its many roles, the chorion is a critical structure in the development of an embryo, and is crucial for a successful pregnancy and healthy live birth of the baby.