chorion

Examples of chorion in the following topics:

• Characteristics of Amniotes

  • However, the eggs of amniotes contain three additional extra-embryonic membranes: the chorion, amnion, and allantois.
  • While the inner amniotic membrane surrounds the embryo itself, the chorion surrounds the embryo and yolk sac.
  • The chorion facilitates exchange of oxygen and carbon dioxide between the embryo and the egg's external environment.
  • The key features of an amniotic egg are the chorion, amnion, and allantois.

• Human Gestation

  • Another layer of the blastocyst, the chorion, begins releasing a hormone called human chorionic gonadotropin (hCG) which makes its way to the corpus luteum, keeping it active.