What is the villi of the placenta?

villi in the placenta Chorionic villi make up a significant portion of the placenta and serve primarily to increase the surface area by which products from the maternal blood are made available to the fetus.

Which types of villi are present in placenta?

At the end of the pregnancy six types of villi are to be found in the placenta:

• Stem villi.
• Tertiary mesenchymatous villi.
• Immature intermediate villi.
• Mature intermediate villi.
• Terminal or free villi.
• Trophoblast buds.

What are the primary chorionic villi the first stage of?

Late in the second week of embryonic development, Extensions of proliferating cytotrophoblast cells evaginate into the syncytiotrophoblast in various places. These extensions are the first stage in the development of the primary villi of the placenta.

What is the primary cell type that composes the chorionic villi of the placenta?

Trophoblastic cells are the cells forming the outer layer of the blastocyst that provide nutrients to the embryo. This layer later develops into a large part of the placenta and so trophoblast-derived cells make up the majority of the chorion in the developed placenta.

What is primary villus?

Primary chorionic villi are solid outgrowths of cytotrophoblast that protrude into the syncytiotrophoblast.

How many placental villi are there?

A mature placenta weighs about 500–600 grams and consists of 15–28 “cotyledons.” The stem villus is the major structural unit of the fetal cotyledon. Each cotyledon begins with a stem villus that divides into 3-5 immature/mature intermediate villi, which further branches into 10–12 terminal villi (Figure 3.1B).

What is the main function of villi?

The villi of the small intestine project into the intestinal cavity, greatly increasing the surface area for food absorption and adding digestive secretions.

What does chorionic villi mean?

The chorionic villi are tiny projections of placental tissue that look like fingers and contain the same genetic material as the fetus. Testing may be available for other genetic defects and disorders depending on the family history and availability of lab testing at the time of the procedure.

What does chorionic villi mean in medical terms?