- Placenta is an organ that lines the uterine wall and feeds a fetus in the womb.
An example of placenta is what a mother cat consumes after giving birth to her kittens.
nounpl. placentas or placentae
- Anat., Zool.
- a vascular organ, developed within the uterus of most mammals during gestation from the chorion of the embryo and a part of the maternal uterine wall, that is connected to the embryo by the umbilical cord and that is discharged shortly after birth: it serves as the structure through which nourishment for the fetus is received from, and wastes of the fetus are eliminated into, the circulatory system of the mother
- any similar structure in other animals
- that part of the lining of the ovary which bears the ovules
- any mass of tissue that bears sporangia or spores
Origin of placentaModern Latin ; from Classical Latin literally , a cake ; from Classical Greek plakounta, accusative of plakous, a flat cake ; from plax (gen. plakos), a flat object ; from Indo-European base an unverified form plāk-, flat from source Classical Latin placere, to please
nounpl. pla·cen·tas or pla·cen·tae
- a. A membranous vascular organ that develops in female eutherian 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.b. A similar organ in marsupial mammals, consisting of a yolk sac attached to the uterine wall.c. 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.
Origin of placentaNew 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.
(plural placentae or placentas)
- (anatomy) A vascular organ in mammals, except monotremes and marsupials, present only in the female during gestation. It supplies food and oxygen from the mother to the foetus, and passes back waste. It is implanted in the wall of the uterus and links to the foetus through the umbilical cord. It is expelled after birth.
- (botany) In flowering plants, the part of the ovary where ovules develop; in non-flowering plants where the spores develop.
From Medieval Latin placenta uterina (“uterine cake"), from Latin placenta (“flat cake"), because of the flat round shape of the afterbirth.