| placental barrier | The semipermeable layer of foetal tissue separating the maternal from the foetal blood in the placenta; composed of: 1) endothelium of the foetal vessels in the chorionic villi, 2) stromata of the villi, 3) cytotrophoblast (negligible after the fifth month of gestation), and 4) syncytial trophoblast covering the villi; the placental membrane acts as a selective membrane regulating passage of substances from the maternal to the foetal blood. Synonym: placental barrier. (05 Mar 2000) |
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| placental calcium-binding protein | <protein> Calcium binding protein of placenta, uterus and vasculature containing the EF hand motif. (18 Nov 1997) |
| placental chorioangioma | <radiology> Most common benign tumour of placenta, incidence: 0.7%, Differential diagnosis: hydatidaform mole, large leiomyoma, chorioepithelioma, complications: IUGR, foetal anomaly, polyhydramnios, haemorrhage, heart failure, premature labour (12 Dec 1998) |
| placental circulation | The circulation of blood through the placenta during intrauterine life, serving the needs of the foetus for aeration, absorption, and excretion; also, maternal circulation through the intervillous space of the placenta. (05 Mar 2000) |
| placental dysfunction | 1. Denoting faulty development or ripening; often connoting structural and/or functional abnormalities. 2. In obstetrics, denoting an infant whose birth weight is inappropriately low for its gestational age. 3. Immature development of the placenta so that normal function does not occur. Synonym: placental dysfunction. (05 Mar 2000) |
| placental dysfunction syndrome | <syndrome> Foetal malnutrition and hypoxia resulting from impaired transfer of oxygen and various nutritive materials from mother to foetus. (05 Mar 2000) |
| placental dysmature | Immature development of the placenta so that normal function does not occur. (05 Mar 2000) |
| placental dystocia | Trouble delivering the placenta (the afterbirth). Dystocia comes from the greek dys meaning difficult, painful, disordered, abnormal + tokos meaning birth. (12 Dec 1998) |
| placental extracts | Extracts prepared from placental tissue; they may contain specific but uncharacterised factors or proteins with specific activities. (12 Dec 1998) |
| placental function tests | Methods used for the assessment of placental function. (12 Dec 1998) |
| placental growth hormone | human placental lactogen |
| placental hormones | Hormones produced by the placenta during pregnancy, including chorionic gonadotropin and substances having oestrogen, progestin, or adrenocorticoid activity. (12 Dec 1998) |
| placental insufficiency | Failure of the placenta to deliver an adequate supply of nutrients and oxygen to the foetus. (12 Dec 1998) |
| placental lactogen | <chemical> A polypeptide hormone secreted by the placenta that enters the maternal circulation and disappears from the circulation immediately after delivery. It has growth-promoting activity, is immunologically similar to human growth hormone, and inhibits maternal insulin activity during pregnancy. By inhibiting glucose oxidation it can increase the glucose supply to a foetus developing in a malnourished mother. Chemical name: Lactogen, placental (12 Dec 1998) |
| placental lobes | Cotyledons of the human placenta, viewed on the maternal surface as irregularly shaped elevations or lobe's. (05 Mar 2000) |