- Anatomy, Zoology. the organ in most mammals, formed in the lining of the uterus by the union of the uterine mucous membrane with the membranes of the fetus, that provides for the nourishment of the fetus and the elimination of its waste products.
- the part of the ovary of flowering plants that bears the ovules.
- (in ferns and related plants) the tissue giving rise to sporangia.
Origin of placenta
Examples from the Web for placenta
Nothing much to use in cleaning up the baby and his mother after the birth, no place to dispose of the placenta.Jesus Wasn’t Born Rich. Think About It.
December 25, 2014
Usually, the disease resolves with the birth of the baby and placenta.Beyond ‘Downton Abbey’: Preeclampsia Maternal Deaths Continue Today
Eleni Tsigas, Christine Morton
January 28, 2013
It normally occurs during weeks six and eight of pregnancy, when the placenta takes over production of hormones from the ovaries.What Exactly Is Wrong With Kate (And Is She Vomiting Blood?) Experts Rush To Explain...
December 3, 2012
You get the biting of the placenta and you get Renesmee biting her without necessarily seeing it.Bill Condon and Melissa Rosenberg on 'Twilight Saga: Breaking Dawn'
November 21, 2011
I had to tell her she had a condition with her placenta that made abortion risky.The Abortion Ban Is Bad Medicine
Willie J. Parker
November 16, 2009
So the allantois of the reptile has become the placenta of the mammal.The Meaning of Evolution
Samuel Christian Schmucker
Proper means should be taken to hasten the expulsion of the placenta.Cattle and Their Diseases
The placenta (and also the child) was considered to be formed of menstrual blood.
It is in fact the placenta, and is also associated with the functions of the Great Mother.
The size and character of the placenta are important qualities.Tomato Culture: A Practical Treatise on the Tomato
William Warner Tracy
- the vascular organ formed in the uterus during pregnancy, consisting of both maternal and embryonic tissues and providing oxygen and nutrients for the fetus and transfer of waste products from the fetal to the maternal blood circulationSee also afterbirth
- the corresponding organ or part in certain mammals
- the part of the ovary of flowering plants to which the ovules are attached
- the mass of tissue in nonflowering plants that bears the sporangia or spores
Word Origin and History for placenta
1670s of plants, 1690s of mammals, from Modern Latin placenta uterina "uterine cake" (so called 16c. by Italian anatomist Realdo Colombo), from Latin placenta "a cake, flat cake," from Greek plakoenta, accusative of plakoeis "flat," related to plax (genitive plakos) "level surface, anything flat," from PIE *plak- (1) "to be flat" (cf. Greek plakoeis "flat," Lettish plakt "to become flat," Old Norse flaga "layer of earth," Norwegian flag "open sea," Old English floh "piece of stone, fragment," Old High German fluoh "cliff"), extended form of root *pele- (2) "flat, to spread" (see plane (n.1)). So called from the shape.
- 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.
- The sac-shaped organ that attaches the embryo or fetus to the uterus during pregnancy in most mammals. Blood flows between mother and fetus through the placenta, supplying oxygen and nutrients to the fetus and carrying away fetal waste products. The placenta is expelled after birth.
- The part of the ovary of a flowering plant to which the ovules are attached. In a green pepper, for example, the whitish tissue to which the seeds are attached is the placenta.
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.