Endoderm Primary

Endoderm is a collection of layers of cells located in the body of the embryo and actively involved in the process of skin formation. At the initial stages of development of the embryo, it forms the cellular basis of the three-layer epithelium of the future placenta and chorion, and subsequently the lungs, bronchi, trachea, main bronchi and other elements of the respiratory system, digestive tract, genitourinary system, etc. develop from it. Primary endoderms from one germ cell at first an intermediate layer is formed - an intermediate zone. From it the hypoblastum is subsequently formed, and then the secondary endoderm.