Extraembryonic coelom

Extraembryonic Coelom

The Extraembryonic Coelom is a significant structure that forms during the early stages of embryonic development. It is a fluid-filled cavity that separates the inner cell mass from the trophoblast in the blastocyst stage of development. The extraembryonic coelom plays a crucial role in the formation of the placenta and the umbilical cord, and it also contributes to the development of the amniotic sac.

Formation

The extraembryonic coelom forms during the second week of embryonic development. It arises from the extraembryonic mesoderm, which is derived from the primitive streak. The extraembryonic mesoderm splits into two layers: the somatic or body layer, which lines the trophoblast, and the splanchnic or visceral layer, which surrounds the amniotic cavity and the yolk sac. The space between these two layers forms the extraembryonic coelom.

Function

The extraembryonic coelom serves several important functions during embryonic development. It provides a protective cushion for the developing embryo, and it allows for the exchange of nutrients and waste products between the mother and the embryo. The extraembryonic coelom also plays a role in the formation of the chorion, which is the outermost layer of the fetal membrane.

Clinical Significance

Abnormalities in the formation of the extraembryonic coelom can lead to a variety of congenital disorders. For example, defects in the formation of the extraembryonic coelom can result in ectopic pregnancy, hydatidiform mole, and placenta previa. Therefore, understanding the development and function of the extraembryonic coelom is crucial in prenatal diagnosis and treatment.

See Also

• Embryogenesis
• Gastrulation
• Blastocyst
• Amniotic sac