Chorion

Definition

The chorion is one of the membranes that develop from the outermost layer of cells in the embryo, known as the trophoblast, surrounding the embryo and forming part of the placenta. It plays a crucial role in gas exchange and nutrient transfer between the mother and the developing fetus.

Related terms

Placenta:

A complex organ formed by the chorion and part of the uterine wall that provides oxygen and nutrients from mother to fetus while removing waste products from fetal blood.

Amnion:

The innermost membrane that surrounds an embryo, forming a protective sac filled with amniotic fluid.

Trophoblast:

The outer layer of cells in early embryonic development that gives rise to both the chorion and parts of the placenta