“Chorionic villi”的意思、由来-开放百科全书

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Chorionic villi

释义

Structure
Development Histology
Clinical significance
Use for prenatal diagnosis Stem cell
Additional images
See also
References
External links

{{Infobox embryology
| Name = Chorionic villi
| Latin =
| Image = Chorionic villi - intermed mag.jpg
| Caption = Micrograph showing chorionic villi. Intermediate magnification. H&E stain.
| Image2 = Chorionic villi - very high mag.jpg
| Caption2 = Micrograph showing chorionic villi. Very high magnification. H&E stain.
| System =
| CarnegieStage =
| Days = 24
| Precursor =
| GivesRiseTo =
}}

Chorionic villi are villi that sprout from the chorion to provide maximal contact area with maternal blood.

They are an essential element in pregnancy from a histomorphologic perspective, and are, by definition, a product of conception. Branches of the umbilical arteries carry embryonic blood to the villi. After circulating through the capillaries of the villi, blood returns to the embryo through the umbilical vein. Thus, villi are part of the border between maternal and fetal blood during pregnancy.

Structure

Villi can also be classified by their relations:

Floating villi float freely in the intervillous space. They exhibit a bi-layered epithelium consisting of cytotrophoblasts with overlaying syncytium (syncytiotrophoblast).
Anchoring (stem) villi stabilize mechanical integrity of the placental-maternal interface.

Development

The chorion undergoes rapid proliferation and forms numerous processes, the chorionic villi, which invade and destroy the uterine decidua and at the same time absorb from it nutritive materials for the growth of the embryo. They undergo several stages, depending on their composition.

Stage	Description	Period of gestation	Contents
Primary	The chorionic villi are at first small and non-vascular.	13–15 days	trophoblast only^[1]
Secondary	The villi increase in size and ramify, while the mesoderm grows into them.	16–21 days	trophoblast and mesoderm^[1]
Tertiary	Branches of the umbilical artery and umbilical vein grow into the mesoderm, and in this way the chorionic villi are vascularized.	17-22 days	trophoblast, mesoderm, and blood vessels^[1]

Until about the end of the second month of pregnancy, the villi cover the entire chorion, and are almost uniform in size—but after then, they develop unequally.

Histology

The bulk of the villi consist of connective tissues that contain blood vessels. Most of the cells in the connective tissue core of the villi are fibroblasts. Macrophages known as Hofbauer cells are also present.

Clinical significance

Use for prenatal diagnosis

In 1983, an Italian biologist named Giuseppe Simoni discovered a new method of prenatal diagnosis using chorionic villi.

Stem cell

Chorionic villi are a rich source of stem cells. Biocell Center, a biotech company managed by Giuseppe Simoni, is studying and testing these types of stem cells. Chorionic stem cells, like amniotic stem cells, are uncontroversial multipotent stem cells.^[2]^[3]^[4]

Additional images

References

1. ^¹²Larsen, William J. : Human embryology. Sherman, Lawrence S.; Potter, S. Steven; Scott, William J. 3. ed.
2. ^{{cite news |url=https://www.reuters.com/article/pressRelease/idUS166682+22-Oct-2009+PRN20091022 |title=European Biotech Company Biocell Center Opens First U.S. Facility for Preservation of Amniotic Stem Cells in Medford, Massachusetts | Reuters |format= |work= |accessdate=2010-01-11 | date=2009-10-22}}
3. ^{{cite news |url=http://www.boston.com/business/ticker/2009/10/europes_biocell.html |title=Europe's Biocell Center opens Medford office - Daily Business Update - The Boston Globe |work= |accessdate=2010-01-11 | date=2009-10-22}}
4. ^{{cite web |url=http://www.bostonherald.com/business/general/view/20091022the_ticker |title=The Ticker - BostonHerald.com |format= |work= |accessdate=2010-01-11}}

External links

http://www.med.umich.edu/lrc/coursepages/M1/embryology/embryo/06placenta.htm

1 : Embryology

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