placenta

noun

pla·cen·ta | \ plə-ˈsen-tə

plural placentas or placentae\ plə-ˈsen-(ˌ)tē

Definition of placenta

1 : the vascular organ in mammals except monotremes and marsupials that unites the fetus to the maternal uterus and mediates its metabolic exchanges through a more or less intimate association of uterine mucosal with chorionic and usually allantoic tissues also : an analogous organ in another animal

2 : a sporangium-bearing surface especially : the part of the carpel bearing ovules

Examples of placenta in a Sentence

Recent Examples on the Web

The raw materials come from placentas donated by women who have given birth by caesarean section. — Charley Grant, WSJ, "Highflying Medical Firm, a Help to Wounded Veterans, Falls to Earth," 23 July 2018 To achieve this scientific feat, Rivron and his team combined embryonic stem cells, which have the potential to form a whole embryo, with trophoblast stem cells, which have the potential to form a placenta. — Susan Scutti, CNN, "Embryo-like structure synthesized in a lab could help decipher infertility," 3 May 2018 The virus, according to the report, can infect the layer of cells in the placenta that's responsible for delivering nutrients to the fetus. — Macaela Mackenzie, Glamour, "Rift Valley Fever Could Be the Next Global Health Crisis For Pregnant Women," 10 Jan. 2019 Another uterine contraction, and doctors deliver the placenta through the cut. — Julia Belluz, Vox, "The troubling epidemic of unnecessary C-sections around the world, explained," 25 Oct. 2018 Early in pregnancy, new blood vessels develop and evolve to send blood to the placenta, the Mayo Clinic explains. — Korin Miller, SELF, "What You Need to Know About Toxemia, the Scary Complication Beyoncé Had While Pregnant With Twins," 6 Aug. 2018 The hazy evidence on smoking weed in pregnancy Since the late 1980s, researchers have known that THC — the active ingredient in cannabis — can cross the placenta and reach the fetus. — Julia Belluz, Vox, "More pregnant women are using marijuana. We don’t know if that’s safe.," 20 Nov. 2018 After your baby and placenta are removed, the incisions will be closed up with sutures. — Korin Miller, SELF, "Here’s What An Emergency C-Section Actually Is," 9 Aug. 2018 The appeals court wrote in its little-noticed opinion on April 24 that the placenta separated from the wall of Dellis’s womb, leading to the death. — Justin Jouvenal, Washington Post, "After disposing of the remains of her stillborn child, she was charged with a crime," 8 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'placenta.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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9 Apr 2019

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The first known use of placenta was in 1638

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More Definitions for placenta

placenta

noun

English Language Learners Definition of placenta

medical : the organ in mammals that forms inside the mother's uterus, nourishes the unborn baby, and is pushed out of the mother after the birth of the baby

See the full definition for placenta in the English Language Learners Dictionary

placenta

noun

pla·cen·ta | \ plə-ˈsen-tə

Kids Definition of placenta

: the organ in most mammals by which the fetus is joined to the uterus of the mother and is nourished

placenta

noun

pla·cen·ta | \ plə-ˈsent-ə

plural placentas or placentae\ -ˈsent-(ˌ)ē

Medical Definition of placenta

: the vascular organ in mammals except monotremes and marsupials that unites the fetus to the maternal uterus and mediates its metabolic 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 and fetal 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 of the uterine mucosa — see abruptio placentae