What are cytotrophoblasts?

“Cytotrophoblast” is the name given to both the inner layer of the trophoblast (also called layer of Langhans) or the cells that live there. It is interior to the syncytiotrophoblast and external to the wall of the blastocyst in a developing embryo.

Is Syncytium the same as syncytiotrophoblast?

As the outermost layer of all villi, the syncytiotrophoblast covers all placental villi as one single layer covering all villi of a single placenta. This layer is a true syncytium, developed and maintained by fusion of mononucleated cells and without any lateral cell borders (Benirschke et al., 2006).

What is the function of the 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.

Why is it called syncytiotrophoblast?

Syncytiotrophoblast (from the Greek ‘syn’- “together”; ‘cytio’- “of cells”; ‘tropho’- “nutrition”; ‘blast’- “bud”) is the epithelial covering of the highly vascular embryonic placental villi, which invades the wall of the uterus to establish nutrient circulation between the embryo and the mother.

What are syncytiotrophoblast cells?

The syncytiotrophoblast (ST) is the placental barrier between maternal and fetal blood that allows exchanges in nutrients and gases and also represents the endocrine tissue of the human placenta. From: 100 Years of Human Chorionic Gonadotropin, 2020.

Does syncytiotrophoblast secrete hCG?

hCG is mainly secreted by the syncytiotrophoblast covering the chorionic villi, but little is known about the source of hyperglycosylated hCG (hCG-H) production.

What is the meaning of syncytial?

(sin-SIH-shee-um) A large cell-like structure formed by the joining together of two or more cells. The plural is syncytia.

How many nuclei does syncytiotrophoblast have?

This peak is somewhat artificial or a cell differentiation artifact, because it is due to the increasing production of hCG with increasing syncytiotrophoblast mass, combined with the growing differentiation of syncytiotrophoblast cells with three to four nuclei into terminally differentiated cells or a syncytium with …

Does syncytiotrophoblast secrete progesterone?

Beginning at about eight weeks of gestation, the syncytiotrophoblast assumes the role of the corpus luteum and begins to secrete the steroid hormones, estrogen and progesterone.

Does the syncytiotrophoblast form the placenta?

The syncytiotrophoblast (ST) is the placental barrier between maternal and fetal blood that allows exchanges in nutrients and gases and also represents the endocrine tissue of the human placenta.

What is the role of syncytiotrophoblast during implantation?

The syncytiotrophoblast facilitates implantation of the blastocyst in the maternal endometrium by production of lytic enzymes and secretion of pro-apoptotic factors. Eventually, the expanding syncytiotrophoblast surrounds the embryo entirely.

What is the difference between syncytium and Coenocytic?

A coenocyte (English: /ˈsiːnəsaɪt/) is a multinucleate cell which can result from multiple nuclear divisions without their accompanying cytokinesis, in contrast to a syncytium, which results from cellular aggregation followed by dissolution of the cell membranes inside the mass.

What is syncytium example?

A classic example of a syncytium is the formation of skeletal muscle. Large skeletal muscle fibers form by the fusion of thousands of individual muscle cells.

Does the syncytiotrophoblast have cell membrane?

In contrast, syncytiotrophoblast cells have complex cytoplasmic contents and cell membrane structure. Thick bundles of tonofilaments are scattered throughout, while the cell surface is covered with many long microvilli.

Does syncytiotrophoblast produce hCG?

What hormones does syncytiotrophoblast secrete?

What is the syncytiotrophoblast in the placenta?

What is the difference between coenocytic and septate hyphae?

Hyphae that are divided into cells are called septate hyphae. However, the hyphae of some fungi are not separated by septa. Hyphae without septae are called coenocytic hyphae.

What syncytial means?

What is difference between hCG and beta hCG?

There are two common types of hCG tests. A qualitative test detects if hCG is present in the blood. A quantitative test (or beta) measures the amount of hCG actually present in the blood.

Does syncytiotrophoblast produce progesterone?

What is the difference between septate and non septate?

The key difference between septate and aseptate hyphae is that septate hyphae have septa or cross walls that divide hyphae into distinct cells while aseptate hyphae lack septa. Hyphae are long filament or thread-like structures of fungi. Hyphae represent the vegetative structure of fungi.

How would you differentiate between septate and coenocytic fungi?

Septa usually have little pores that are large enough to allow ribosomes, mitochondria and sometimes nuclei to flow among cells. Hyphae that are divided into cells are called septate hyphae. However, the hyphae of some fungi are not separated by septa. Hyphae without septae are called coenocytic hyphae.

What is the difference between beta and alpha hCG?

The alpha-subunit contains 2 N-linked oligosaccharides; the beta-subunit contains 2 N-linked oligosaccharides, as well as 4 O-linked oligosaccharides on the C-terminal extension. The 2 most common forms of hCG synthesized by cells are regular hCG and hyperglycosylated hCG (hCG-H).

What are the different types of hCG?

Three major forms of hCG are produced by humans, with each having distinct physiological roles. These include regular hCG, hyperglycosylated hCG, and the free beta-subunit of hCG.

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.

What is syncytiotrophoblast in vitro?

Figure 1: Isolated cytotrophoblast cells fuse and differentiate to form syncytiotrophoblast in vitro. The cellular cytotrophoblast (CTB), a progenitor epithelium which regenerates the syncytiotrophoblast (SCT) continuously, can be isolated and cultured in vitro.

What is the cytotrophoblast?

The cytotrophoblast (or layer of Langhans) is the inner layer of the trophoblast. It is interior to the syncytiotrophoblast and external to the wall of the blastocyst in a developing embryo.

Does trophoblast syncytialisation require mitochondrial function?

Poidatz, D. et al. Trophoblast syncytialisation necessitates mitochondrial function through estrogen-related receptor-γ activation. Mol. Hum. Reprod. 21, 206–216 (2015).