Search results
Results From The WOW.Com Content Network
The trophoblast (from Greek trephein: to feed; and blastos: germinator) is the outer layer of cells of the blastocyst. Trophoblasts are present four days after fertilization in humans. [ 1 ] They provide nutrients to the embryo and develop into a large part of the placenta .
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.
Trophoblast cells also secrete factors to make the blastocoel. [25] After implantation, cytotrophoblast is the inner layer of the trophoblast, composed of stem cells which give rise to cells comprising the chorionic villi, placenta, and syncytiotrophoblast. After implantation, syncytiotrophoblast is the outermost layer of the trophoblast.
Blastocyst with an inner cell mass and trophoblast. Cleavage itself is the first stage in blastulation, the process of forming the blastocyst. Cells differentiate into an outer layer of cells called the trophoblast, and an inner cell mass. With further compaction the individual outer blastomeres, the trophoblasts, become indistinguishable.
They are sometimes called intermediate trophoblast. [1] EVTs that derive from CYT cells on the surface of placental chorionic villi that come into contact with the uterine wall - at the placental bed - begin to express the HLA-G antigen. [2] Extravillous trophoblast (EVT) cells migrate from anchoring villi, and invade into the decidua basalis.
Image showing trophoblast differentiated into the two layers of cytotrophoblast and syncytiotrophoblast during implantation. It is the outer layer of the trophoblasts and actively invades the uterine wall, during implantation, rupturing maternal capillaries and thus establishing an interface between maternal blood and embryonic extracellular fluid, facilitating passive exchange of material ...
The smallest were slimmer than the diameter of a human red blood cell, which measures about 8 micrometers. The most common type of plastic they found was polypropylene, followed by polyamide ...
It harbors the largest population of proliferating cells in the adult brain of rodents, monkeys and humans. [12] In 2010, it was shown that the balance between neural stem cells and neural progenitor cells (NPCs) is maintained by an interaction between the epidermal growth factor receptor signaling pathway and the Notch signaling pathway. [13]