Developmental Biology Extraembryonic Structures

What is the chorion?

The outermost extraembryonic membrane that contributes to formation of the placenta.

What is the function of the allantois?

Contributes to blood vessel formation and becomes part of the umbilical cord; involved in early waste exchange.

What is the amniotic cavity?

A fluid-filled space surrounding the embryo that cushions and protects it.

What is the placenta?

An organ formed from maternal and fetal tissues that allows nutrient, gas, and waste exchange between mother and fetus.

What is the maternal portion of the placenta?

The part derived from the uterine endometrium (mother's tissue).

What is the fetal portion of the placenta?

The part derived from the chorion (fetal tissue).

What is the umbilical cord?

A structure connecting the embryo/fetus to the placenta containing blood vessels for nutrient and waste exchange.

What are extraembryonic membranes?

Membranes that support the embryo but do not become part of the embryo itself (amnion, chorion, yolk sac, allantois).

What is the function of the yolk sac?

Provides early nutrient transfer, forms the first blood cells, and contributes to primordial germ cells.

What is the amnion?

A membrane that surrounds the embryo, forming the amniotic cavity filled with fluid.

What is the embryo?

The developing organism during early stages of development.