fetal placenta

placenta /pla·cen·ta/ (plah-sen´tah) pl. placentas, placen´tae   [L.] an organ characteristic of true mammals during pregnancy, joining mother and fetus, providing endocrine secretion and selective exchange of soluble bloodborne substances through apposition of uterine and trophoblastic vascularized parts.placen´tal

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placenta accre´ta  one abnormally adherent to the myometrium, with partial or complete absence of the decidua basalis.

circumvallate placenta  one in which a dense peripheral ring is raised from the surface and the attached membranes are doubled back over the placental edge.

deciduate placenta , deciduous placenta a placenta or type of placentation in which the decidua or maternal parts of the placenta separate from the uterus and are cast off together with the trophoblastic parts.

fetal placenta  the part of the placenta derived from the chorionic sac that encloses the embryo, consisting of a chorionic plate and villi.

hemochorial placenta  one in which maternal blood comes in direct contact with the chorion, as in humans.

placenta incre´ta  placenta accreta with penetration of the myometrium.

maternal placenta  the maternally contributed part of the placenta, derived from the decidua basalis.

placenta membrana´cea  one that is abnormally thin and spread out over an unusually large area of the uterine wall.

placenta percre´ta  placenta accreta with invasion of the myometrium to its peritoneal covering, sometimes causing rupture of the uterus.

placenta pre´via  one located in the lower uterine segment, so that it partially or completely covers or adjoins the internal os.

placenta spu´ria  an accessory portion having no blood vessel attachment to the main placenta.

placenta succenturia´ta , succenturiate placenta an accessory portion attached to the main placenta by an artery or vein.

villous placenta  one characterized by the presence of villi that are outgrowths of the chorion.

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fetal placenta

n.

The chorionic portion of the placenta, containing the fetal blood vessels, from which the umbilical cord arises.

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fetal placenta

Etymology: L, fetus + placenta, flat cake

the portion of the placenta that is formed from the shaggy chorion frondosum, the villi of which invade the decidua basalis. Also called parsfetalis.