placental (redirected from Placentals)

placental

[pləsen′təl]

Etymology: L, placenta, flat cake

pertaining to the placenta.

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placental

pertaining to or emanating from placenta.

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placental barrier

the placental separation of maternal and fetal blood which varies in its structure and permeability between the species. In general the more layers of cells between the two circulations the less permeable the membrane. In none of the domestic animals are significant amounts of immune globulins or erythrocyte antigens passed through the membranes unless the epithelium is damaged. See also placenta.

placental calcification

accumulations of mineral deposit especially around the vessels and in the allantois, a normal occurrence in most species.

placental cavities

the allantoic and amniotic cavities; called also amniotic and allantoic sac.

placental edema

edema of the placenta, without necessarily any involvement of the fetus.

placental hormones

the placenta in all species produces estrogens and progesterone. In the cow it also produces lactogen, a hormone that influences structural and functional aspects of milk production. In the mare the endometrial cups produce pmsg (now called eCG) which assists in the maintenance of pregnancy. The equine, feline and primate placentae also produce relaxin which has a similar action.

placental implantation

the placenta of a viable fetus, escaped from the genital tract, can implant successfully to the peritoneum.

placental inflammation

see placentitis.

placental lactogen

a placental hormone present in the cow's peripheral circulation at about 160 days of pregnancy; thought to have prolactin and growth-hormone capabilities.

placental mole

see mole.

placental plaques

are normal structures on the amnion in most species. They are foci of squamous epithelium.

placental removal

manual removal per vagina, detaching the placenta from each caruncle in turn.

placental transfer of immunoglobulins

see placental barrier (above) and passive immunity.

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hydrops fetalis

Kernicterus, Rh incompatibility, Rh-induced hemolytic disease of newborn Obstetrics An accumulation of fluid in neonates, resulting in a 'puffy', plethoric or hydropic appearance that may be due to various etiologies Clinical Ascites, edema, ↓ protein or chronic intrauterine anemia, hepatosplenomegaly, cardiomegaly, extramedullary hematopoiesis, jaundice, pallor COD Heart failure. See Hemolytic disease of the newborn.

Hydrops Fetalis, causes

Immune Mother produces IgG antibodies against infant antigen(s), often an RBC antigen, most commonly, anti-RhD, which then passes into the fetal circulation, causing hemolysis

Non-immune Hydrops may result from various etiologies including

•  Fetal origin, eg congenital heart disease (premature foramen ovale closure, large AV septal defect), hematologic (erythroblastosis fetalis, α-thalassemia due to hemoglobin Barts, chronic fetomaternal or twin-twin transfusion), infection (CMV, herpesvirus, rubella, sepsis, toxoplasma), pulmonary (cystic adenomatoid malformation, diaphragmatic hernia, with pulmonary hypoplasia, lymphangiectasia), renal (vein thrombosis, congenital nephrosis) and teratomas, skeletal malformations (achondroplasia, osteogenesis imperfecta, fetal neuroblastomatosis, storage disease, meconium peritonitis, idiopathic)

•  Placental Chorangioma, umbilical or chorionic vein thrombosis

•  Maternal DM, toxemia