What is the function of the cytotrophoblast?
The primary function of the endovascular cytotrophoblast is to penetrate maternal spiral arteries and route the blood flow through the placenta for the growing embryo to use.
What is the villous cytotrophoblast?
The villous cytotrophoblast cellss are located in the innermost chorionic villi layer of the placenta. These are mononuclear cells which are found as early as day 7 in humans and are characteristic of stages 8.00-13.00 of mouse development.
What do chorionic villi do?
During pregnancy, the placenta provides oxygen and nutrients to the growing baby and removes waste products from the baby’s blood. The chorionic villi are wispy projections of placental tissue that share the baby’s genetic makeup. The test can be done as early as 10 weeks of pregnancy.
What structure originates from the cytotrophoblast?
Just as the undifferentiated basal layer of the skin gives rise to differentiated keratinocytes, the cytotrophoblast—the stem cell of the placenta—gives rise to the differentiated forms of trophoblasts. Left) Within the chorionic villi, cytotrophoblasts fuse to form the overlying syncytiotrophoblast.
Does cytotrophoblast produce hCG?
Cytotrophoblast cells naturally produce hyperglycosylated hCG, which promotes their growth and invasion. Other cells need to be transformed to produce invasive hyperglycosylated hCG.
What are syncytiotrophoblast cells?
The syncytiotrophoblasts are a continuous, specialized layer of epithelial cells. They cover the entire surface of villous trees and are in direct contact with maternal blood. The surface area of syncytiotrophoblasts is about 5 square meters at 28 weeks’ gestation and reaches up to 11–12 square meters at term .
What is the difference between cytotrophoblast and syncytiotrophoblast?
The syncytiotrophoblast is a rapidly growing multinucleated mass, which invades and ruptures endometrial capillaries forming lacunae. The cytotrophoblast is a layer of mononucleated cells, which invades the syncytiotrophoblast matrix and forms early chorionic villi.
How chorionic villi is formed?
As the chorion develops, it sends small outpouchings of cytotrophoblast into the surrounding syncytiotrophoblast to form primary chorionic villi. They begin to branch near the end of the second week of gestation, and by the beginning of the third week, mesenchyme grows into the cytotrophoblast to form secondary villi.
What is villi and trophoblast?
Villi attached to the maternal tissues via the trophoblastic shell are called stem or anchoring villi. Villi that grow from the sides of the stem villi are called branch villi, and it is through these that the major exchange of materials between the mother and the embryo takes place.
What is lacunar network?
The lacunar-canalicular network (LCN) of bone contains osteocytes and their dendritic extensions, which allow for intercellular communication, and are believed to serve as the mechanosensors that coordinate the processes of bone modeling and remodeling.
What is the function of syncytiotrophoblast?
The syncytiotrophoblast, the outermost layer of the human placenta, is the main site of exchange for drugs and metabolites, nutrients, waste products, and gases between the maternal and fetal circulations.
What are cytotrophoblast and syncytiotrophoblast?
What is the cytotrophoblast?
The cytotrophoblast is a layer of mononucleated cells, which invades the syncytiotrophoblast matrix and forms early chorionic villi. Oxygen exchange occurs between the villi and the lacunae, and oxygen also diffuses into the extraembryonic tissue. The bilaminar embryo forms adjacent to the secondary yolk sac. Sign in to download full-size image
What are villous trophoblasts made up of?
Villous trophoblasts have two cell populations: undifferentiated cytotrophoblasts and fully differentiated syncytiotrophoblasts. The syncytiotrophoblasts are a continuous, specialized layer of epithelial cells. They cover the entire surface of villous trees and are in direct contact with maternal blood.
What is villous syncytiotrophoblast?
The villous syncytiotrophoblast is a terminally differentiated, mitotically inactive cell type, with amphophilic to eosinophilic cytoplasm and multiple small, hyperchromatic nuclei.
How does a cytotrophoblastic stem cell differentiate into a syncytiotrophoblast?
An undifferentiated cytotrophoblastic stem cell will differentiate into a villous cytotrophoblast, which is what constitutes primary chorionic villi, and will eventually coalesce into villous syncytiotrophoblast. The formation of syncytiotrophoblast from cytotrophoblast is a terminal differentiation step of trophoblastic cells.