placental barrier


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Related to placental barrier: Blood brain barrier

barrier

 [bar´e-er]
1. an obstruction.
2. a partition between two fluid compartments in the body.
3. a covering used to prevent contact with body fluids.
alveolar-capillary barrier (alveolocapillary barrier) see under membrane.
blood-air barrier alveolocapillary membrane.
blood-aqueous barrier the physiologic mechanism that prevents exchange of materials between the chambers of the eye and the blood.
blood-brain barrier see blood-brain barrier.
blood-gas barrier alveolocapillary membrane.
blood-testis barrier a barrier separating the blood from the seminiferous tubules, consisting of special junctional complexes between adjacent Sertoli cells near the base of the seminiferous epithelium.
barrier methods contraceptive methods such as condoms and diaphragms in which a plastic or rubber barrier blocks passage of spermatozoa through the vagina or cervix. See discussion under contraception.
placental barrier the tissue layers of the placenta which regulate the exchange of substances between the fetal and maternal circulation.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

pla·cen·tal mem·brane

the semipermeable layer of fetal tissue separating the maternal from the fetal blood in the placenta; composed of: 1) endothelium of the fetal vessels in the chorionic villi, 2) stromata of the villi, 3) cytotrophoblast (negligible after the fifth month of gestation), and 4) syncytiotrophoblast covering the villi; the placental membrane acts as a selective membrane regulating passage of substances from the maternal to the fetal blood.
Synonym(s): placental barrier
Farlex Partner Medical Dictionary © Farlex 2012

pla·cen·tal mem·brane

(plă-sen'tăl mem'brān)
The semipermeable layer of fetal tissue separating the maternal from the fetal blood in the placenta; composed of: 1) endothelium of the fetal tissues in the chorionic villi, 2) stromata of the villi, 3) cytotrophoblast (negligible after the fifth month of gestation), and 4) syncytiotrophoblast covering the villi; the placental membrane acts as a selective membrane regulating passage of substances from the maternal to the fetal blood.
Synonym(s): placental barrier.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
Another cause of low p[O.sub.2] in the chorionic villus blood may be the excessive thickness of the placental barrier (Kumar et al., 2000).
Women who want to get pregnant and are trying to do so should remember that everything that goes into the mouth crosses the placental barrier. The March of Dimes recommends, therefore, that women who really want to play it safe should refrain from the use of caffeine-containing products whenever they are actively trying to become pregnant.
These potent neurotoxins can enter the body via dermal absorption and ingestion, build up over time and pass through the placental barrier affecting early development of the baby's brain," said Thony Dizon, Chemical Safety Campaigner, EcoWaste Coalition.
This is called the placental barrier that separates the fetal and maternal blood (Laurini et al., 1987).
Studies on placental barrier function have produced discordant results (9,10).
A case study conducted in Brazil revealed the presence of Zika virus in the amniotic fluid of two pregnant women, suggesting that the virus can cross the placental barrier and potentially infect the developing fetus.
Therefore, it will be increasingly important to investigate NP transport across internal barriers such as the placental barrier between the mother and the unborn child.
However the incidence is less, various studies estimating the prevalence between 0.3 -10%, presumably due to effective placental barrier and transplacentally transferred maternal antibodies.
Cocaine is lipid soluble, easily crosses the placental barrier and the fetal blood brain barrier and tends to be sequestered in the brain.
The report also charges that mercury can cross the placental barrier into the tissue of a developing fetus, and it implicates the metal in kidney impairment, loss of immune function, antibiotic resistance and lowered fertility.
According to the US National Institute for Occupational Safety and Health (NIOSH), "lead can cross the placental barrier which means pregnant women who are exposed to lead also expose their unborn child."