Chorionic sac

Chorionic Sac

The chorionic sac is an essential component of the pregnancy process in mammals, including humans. It is formed after the fertilization of an egg by a sperm, and its primary function is to protect and nourish the developing embryo or fetus.

Formation

The formation of the chorionic sac begins shortly after fertilization. The fertilized egg, or zygote, begins to divide and form a ball of cells known as a blastocyst. The outer layer of the blastocyst, the trophoblast, will eventually form the chorionic sac.

Structure

The chorionic sac is composed of two layers: the outer chorion and the inner amnion. The chorion is the maternal part of the placenta and contributes to the formation of the umbilical cord. The amnion, on the other hand, is a thin, tough membrane that contains the amniotic fluid and the fetus.

Function

The chorionic sac serves several critical functions during pregnancy. It provides a protective environment for the developing fetus, helps to regulate temperature, and facilitates the exchange of nutrients and waste products between the mother and the fetus. The chorionic sac also produces several important hormones, including human chorionic gonadotropin (hCG), which is used as a marker in pregnancy tests.

Clinical Significance

Abnormalities in the chorionic sac can lead to a variety of pregnancy complications, including miscarriage, ectopic pregnancy, and chorionic villus sampling (CVS). Therefore, the health of the chorionic sac is often monitored during prenatal care.

See Also

• Amniotic sac
• Placenta
• Pregnancy