The chorion is the outermost fetal membrane around the embryo in mammals, birds and reptiles (amniotes). It is also present around the embryo of other animals, like insects and molluscs.

chorion, in reptiles, birds, and mammals, the outermost membrane around the embryo. It develops from an outer fold on the surface of the yolk sac. In insects the chorion is the outer shell of the insect egg.

Oct 30, 2023 · The chorion is the outermost of the four membranes surrounding the developing fetus, consisting of trophoblast and underlying extraembryonic mesoderm. It is continuous with the lining of …

Jul 24, 2025 · During pregnancy, two protective membranes, the chorion and the amnion, develop around the growing embryo and fetus. These membranes work together to form the amniotic sac, a …

Apr 28, 2023 · The chorion is the outermost membrane that surrounds the developing embryo, while the amnion is a fluid-filled sac that surrounds the embryo and helps to protect it from mechanical shock …

The meaning of CHORION is the highly vascular outer embryonic membrane of reptiles, birds, and mammals that in placental mammals is associated with the allantois in the formation of the placenta.

Chorion is defined as the nonliving shell encapsulating the eggs of oviparous fish species, also known as the zona radiata, though it is not homologous with the chorion of amniotes.

Chorion is a protective membrane structure that surrounds embryonic and fetal development in many species, including humans.

Jun 14, 2025 · The chorion is the outermost membrane surrounding the embryo, formed from the trophoblast and the extraembryonic mesoderm. It develops from the cytotrophoblast and …

Oct 4, 2019 · The chorion is one of the membranes that surround the fetus while it is still being formed. In mammals, the fetus lies in the amniotic sac, which is formed by the chorion and the amnion and …