Ask AI: Discuss two ways in which amnion and chorion are formed in mammals and state their functions

In mammals, the amnion and chorion are both essential parts of the extra-embryonic membranes that develop during the gestation period. These membranes play a crucial role in protecting and nourishing the developing embryo. Here, we will discuss two ways in which these membranes are formed, and their respective functions. 1. Formation: a) Amnion: The amnion is formed from the inner cell mass of the pre-implantation embryo, known as the epiblast. As the embryo undergoes gastrulation, the epiblast differentiates into ectoderm, mesoderm, and endoderm. A portion of the epiblast-derived ectoderm and mesoderm will fold on itself to create a fluid-filled sac known as the amniotic cavity. The ectoderm portion forms the amniotic ectoderm, which lines the inner surface of the amniotic cavity, whereas the mesoderm portion forms the amniotic mesoderm, which lines the outer surface of the amniotic cavity. Together, these layers form the amnion. b) Chorion: The chorion is formed primarily from the extra-embryonic mesoderm and trophectoderm. As the embryo implants into the uterine wall, the extra-embryonic mesoderm expands and differentiates into two layers: the somatic extra-embryonic mesoderm and the splanchnic extra-embryonic mesoderm. The somatic extra-embryonic mesoderm combines with the underlying trophectoderm to form the chorion. 2. Functions: a) Amnion: The primary function of the amnion is to enclose the embryo within the amniotic fluid-filled sac. The amniotic fluid serves as a cushion to protect the developing embryo from physical shocks and maintain a stable temperature. It also allows the embryo to move and develop muscles freely without being constrained by the uterine wall. Moreover, the amniotic fluid facilitates the exchange of nutrients, waste products, and gases between the embryo and the mother's blood supply through the placenta. b) Chorion: The main function of the chorion is to contribute to the formation of the mammalian placenta, which is crucial for providing oxygen and nutrients to the developing embryo and removing waste products. The chorion has finger-like projections called chorionic villi which extend into the maternal uterine tissue. The villi establish a connection with maternal blood vessels, allowing for efficient gas, nutrient, and waste exchange. Additionally, the chorion is involved in the production of pregnancy hormones, such as human chorionic gonadotropin (hCG), which supports the maintenance of the pregnancy by preventing the breakdown of the corpus luteum and ensuring progesterone production.