Placentae

pla·cen·ta   (plə-sěn'tə)    n.   pl. pla·cen·tas or pla·cen·tae (-tē) A membranous vascular organ that develops in female mammals during pregnancy, lining the uterine wall and partially enveloping the fetus, to which it is attached by the umbilical cord. Following birth, the placenta is expelled. An organ with similar functions in some nonmammalian animals, such as certain sharks and reptiles. Botany The part within the ovary of a flowering plant to which the ovules are attached. [New Latin, from Latin, flat cake, alteration of Greek plakoenta, from accusative of plakoeis, flat, from plax, plak-, flat land, surface; see plāk-1 in Indo-European roots.] pla·cen'tal adj.

placenta [(pluh-sen-tuh)]

An organ that forms in the uterus after the implantation of a zygote. The placenta moves nourishment from the mother's blood to the embryo or fetus; it also sends the embryo or fetus's waste products into the mother's blood to be disposed of by the mother's excretory system. The embryo or fetus is attached to the placenta by the umbilical cord. After birth, the placenta separates from the uterus and is pushed out of the mother's body.

placenta 

Main Entry: pla·cen·ta
Pronunciation: pl&-'sent-&
Function: noun
Inflected Form: plural pla·centas or pla·cen·tae /-'sent-(")E/
: the vascular organ in mammals except monotremes and marsupials that unites the fetus to the maternal uterus and mediates itsmetabolic exchanges through a more or less intimate association of uterine mucosal with chorionic and usually allantoic tissues permitting exchange of material by diffusion between the maternal andfetal vascular systems but without direct contact between maternal and fetal blood and typically involving the interlocking of fingerlike vascular chorionic villi with corresponding modified areas ofthe uterine mucosa —see ABRUPTIO PLACENTAE

placenta pla·cen·ta (plə-sěn'tə)
n. pl pla·cen·tas or pla·cen·tae (-tē)
The membranous vascular organ in female mammals that permits metabolic interchange between fetus and mother. It develops during pregnancy from the chorion of the embryo and the decidua basalis of the maternal uterus and permits the absorption of oxygen and nutritive materials into the fetal blood and the release of carbon dioxide and nitrogenous waste from it, without the direct mixing of maternal and fetal blood. It is expelled following birth.

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pla·cen'tal adj.