• WordNet 3.6
    • n placenta the vascular structure in the uterus of most mammals providing oxygen and nutrients for and transferring wastes from the developing fetus
    • n placenta that part of the ovary of a flowering plant where the ovules form
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Webster's Revised Unabridged Dictionary
    • Placenta (Bot) The part of a pistil or fruit to which the ovules or seeds are attached.
    • Placenta (Anat) The vascular appendage which connects the fetus with the parent, and is cast off in parturition with the afterbirth.
    • ***
Century Dictionary and Cyclopedia
    • n placenta In zoöl., anat., and medicine: The organ of attachment of a vertebrate embryo or fetus to the wall of the uterus or womb of the female. It is a specially modified part of the surface of the chorion or outside one of the fetal envelops, of a flattened circular form, like a plate or saucer, one side of which is closely applied to the wall of the womb, and from the other side of which proceeds the umbilical cord or navel-string. It is highly vascular, and in intimate vital connection with a similarly vascular area of the uterine walls, serving for the interchange of the constituents of the blood between the female and the fetus, and thus acting during in-tra-uterine life as the organ of circulation, respiration, and nutrition of the fetus. The human placenta is about as large as a soup-plate, and in connection with the navel-string and membranes is commonly known as the uterine cake, afterbirth, or secundines. The presence of a true placenta is necessarily restricted to viviparous vertebrates, and does not occur in all of these (the two lower subclasses of mammals, the marsupials and monotremes, being implacental). Several forms of placenta have been distinguished among placental mammals, and made a basis of classification. See also cuts under embryo and uterus.
    • n placenta In echinoderms, a flat discoidal sea-urchin, as a sand-dollar or cake-urchin: used in a generic sense by Klein, 1734.
    • n placenta [capitalized] A genus of bivalve mollusks, now called Plaruna.
    • n placenta In botany, that part of the ovary of flowering plants which bears the ovules. It is usually the more or less enlarged or modified margins of the carpellary leaves, and is of a soft cellular texture. When the ovary is composed of a single leaf, both margins give rise to ovules, and they are consequently in two rows. In a compound ovary there are various modifications of the placenta. Thus.when the edges of the car-pellary leaes all meet in a common axis, the placentas are said to be axile. When, by obllteration of the dissepiments, such an ovary becomes one-celled, the axile placentas remain in a column as a free central placenta. Or, when the edges of the carpellary leaves barely meet and slightly incurve, the placentas become parietal, being borne on the wall. There are all degrees of incurvation, the placentas being located accordingly. In vascular cryptogams the point giving rise to the sporangia is sometimes called the placenta. The placenta is sometimes termed the trophospermium and spermophorum. See also cut under ovary.
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Chambers's Twentieth Century Dictionary
    • n Placenta pla-sen′ta the structure which unites the unborn mammal to the womb of its mother and establishes a nutritive connection between them:
    • n Placenta a mammal having a placenta
    • n Placenta pla-sen′ta (bot.) the portion of the ovary which bears the ovules
    • ***


  • John Berger
    “The past grows gradually around one, like a placenta for dying.”


Webster's Revised Unabridged Dictionary
L., a cake, Gr. a flat cake, from flat, fr. , , anything flat and broad
Chambers's Twentieth Century Dictionary
L., a flat cake, akin to Gr. plakous, a flat cake, from plax, plak-os, anything flat.


In literature:

Her blood seeps over into the transformed allantois which is now called a placenta.
"The Meaning of Evolution" by Samuel Christian Schmucker
The placenta.= The womb or uterus is the size of a small egg flattened in one direction.
"The Sexual Question" by August Forel
In some animals the young have structures that attach them to the mother, as does the placenta of the mammals.
"A Critique of the Theory of Evolution" by Thomas Hunt Morgan
Slowly, doctor, look out for the placenta.
"The "Genius"" by Theodore Dreiser
PLACENTA, a name given to the surface, whatever it be, which bears the ovules and seeds.
"The Elements of Botany" by Asa Gray
A good deal of the matters filtered by the placenta are mineral in their nature, and such portions as are not digested remain in the crease.
"Encyclopaedia Britannica, 11th Edition, Volume 10, Slice 5" by Various
The seeds adhere longitudinally to the middle of the placenta (or receptacle).
"Lachesis Lapponica" by Carl von Linné
No nerves run in the cord and none pass from the uterine tissues to the placenta.
"Psychotherapy" by James J. Walsh
From the centre processes pass outwards, ending in the curved placenta.
"Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3" by Various
Another structure, concerning which just a word must be said, is that known as the "placenta," or more commonly as the "after-birth.
"Embryology" by Gerald R. Leighton

In news:

Back to WYMT Better Living Eastern KY. Federal regulators are ordering several companies to stop selling an unproven weight loss remedy that uses protein from the human placenta.
Would you eat your own placenta to avoid postpartum depression.
Postnatal placenta remedies gaining popularity in Columbia.
Placenta shampoos, BPA, and Monsanto's genetic empire.
Postnatal placenta remedies gaining popularity in Columbia.
The science behind this internet diagnosis is pretty solid, as many testicular cancers produce the same pregnancy-test triggering hormone that a placenta would.
A Different Way to Remove the Placenta May Save Mothers' Lives, a Study Finds.
The hospital has a program in place for women who are having a repeat c-section who are not in labor to donate their placenta.
The placenta goes to a company that uses it for research to grow human tissue for skin grafts.
And why not eat your own placenta.
Would you eat your placenta.
Some mothers see health benefits in eating their placenta after giving birth .
A day after the Mexican pop star Gloria Trevi gave birth in a Brasília prison, the Supreme Court upheld its decision to request storing her placenta for possible DNA testing to identify the baby's father.
Some of the tissue was taken from placentas cleaned in the kitchen sink of a midwife and stored in her refrigerator, prosecutors argued.