chorionic villi

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Related to chorionic villi: hydatidiform mole


pertaining to the chorion.
chorionic villi numerous branching projections from the external surface of the chorion that provide for exchange between the maternal and fetal circulation. Oxygen and nutrients in the maternal blood diffuse through the walls of the villi and enter the blood of the embryo or fetus. Carbon dioxide and waste products diffuse from blood in the fetal capillaries through the walls of the villi into the maternal blood. See also chorionic villus sampling.


 [vil´us] (L.)
a small vascular process or protrusion, as from the free surface of a membrane.
arachnoid villi microscopic projections of the arachnoid into some of the venous sinuses.
chorionic villi see chorionic villi.
intestinal villi multitudinous threadlike projections covering the surface of the mucous membrane lining the small intestine, serving as the sites of absorption of fluids and nutrients.
synovial villi slender projections from the surface of the synovial membrane into the cavity of a joint; called also haversian glands.

cho·ri·on·ic vil·li

vascular processes of the chorion of the embryo entering into the formation of the placenta.

cho·ri·on·ic vil·li

(kōr'ē-on'ik vil'ī)
Vascular processes of the chorion of the embryo entering into the formation of the placenta.

chorionic villi

The finger-like projections from the CHORION into the wall of the womb at the site at which the PLACENTA is developing. Since both the chorionic villi and the embryo are derived from the same fertilized ovum a sample of the former provides material for genetic studies of the latter. Chorionic villus sampling has become an important method of early pre-natal screening for genetic defects.

Chorionic villi

Microscopic, finger-like projections that emerge from the outer sac which surrounds the developing baby. Chorionic villi are of fetal origin and eventually form the placenta.
References in periodicals archive ?
The preuterine pattern (PR) of chronic, hypoxic placental injury features, histologically, homogeneous placental maturation (ie, the chorionic villi are plump and of similar size from field to field); increased villous vascularity, including practically all cases of diffuse chorangiosis; decreased extracellular matrix of chorionic villi and villous cytotrophoblasts; increased Hofbauer cells; and increased nonapoptotic syncytial knotting (21,31) (Figure 2, A).
These statements can be misleading to couples contemplating the procedure," said O'Connor, a New York City lawyer who represents plaintiffs in chorionic villi sampling cases.
To resolve the discrepancy between the biochemical results from native and cultured chorionic villi, we first investigated the genetic identity of the cultured chorionic villus specimen by analyzing nine different polymorphic short tetranucleotide repeat loci and the X-Y homologous gene amelogenin with the AmpF/STRT[TM] Profiler Plus Kit (Applied Biosystems).
Currently, many patients are having invasive testing such as amniocentesis or chorionic villi sampling, that puts their pregnancy at some risk, and that risk could be eliminated with this technology.
Their announced goal is to find an alternative to invasive procedures such as amniocentesis and chorionic villi sampling, which can be risky as well as costly.
Prenatal diagnosis is possible by measuring the enzyme activity in cultured amniocytes or chorionic villi.
Patients can have chorionic villi sampling (CVS) at 10-12 weeks or an earlier amniocentesis.
While the test still is under development, if proven effective, it could provide noninvasive, earlier prenatal screening and possibly eliminate the need for amniocentesis and chorionic villi sampling (CVS).
Microscopically it showed an increase in the number of vessels in the chorionic villi, a characteristic finding of chorangiosis.
Prenatal diagnosis for all of these diseases is possible through amniotic fluid or chorionic villi sampling when both parents are carriers.
Eng and her associates discovered that there was a 71% acceptance rate of CMA among couples in which the woman was undergoing amniocentesis or chorionic villi sampling (CVS).
Diffuse sclerosis of some chorionic villi was noted.