placenta

noun

pla·​cen·​ta plə-ˈsen-tə How to pronounce placenta (audio)
plural placentas or placentae plə-ˈsen-(ˌ)tē How to pronounce placenta (audio)
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 Today, microplastics are found almost everywhere: oceans, food, the atmosphere and even human lungs, blood and placentas. Aaron Boorstein, Smithsonian Magazine, 29 Mar. 2024 Studies so far have found microplastics to be harmful in mice and have also detected them in different parts of the human body — like the placenta, liver, and lungs — but there has been less research showing how much microplastics actually affect people’s health. Elaine Chen, STAT, 6 Mar. 2024 The phthalates can in turn get into the bloodstream and travel into the placenta, which may cause negative outcomes for both the fetus and the pregnant person.1 The idea that phthalates can cause harm isn’t new. Anna Halkidis, Parents, 6 Mar. 2024 Microplastics permeate the food chain, showing up in 83 percent of our tap water and have even been discovered in human placentas. Evan Halper, Washington Post, 14 Feb. 2024 Prior research suggested that the chemicals can act as hormone disruptors and impact the placenta, which aids a developing fetus in the womb. Nicholas Rice, Peoplemag, 10 Feb. 2024 Charlotte Moore, a patient-care technician, and Benedict Landgren, an ob-gyn, perform a uterine aspiration, in which suction is used to remove the fetus, placenta, or other membrane tissue. Maggie Shannon, The New Yorker, 5 Feb. 2024 Most people with this infection have little or no symptoms, but there is a unique risk to pregnant women because toxoplasmosis can be transmitted through the placenta. Katia Hetter, CNN, 29 Feb. 2024 Iron needs increase during pregnancy because a pregnant person’s blood volume expands significantly in order to maintain proper circulation and to deliver sufficient oxygen to their own tissues, as well as to the placenta and baby. Casey Seiden, Parents, 26 Feb. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'placenta.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

New Latin, from Latin, flat cake, from Greek plakoenta, accusative of plakoeis, from plak-, plax flat surface — more at fluke entry 2

First Known Use

1638, in the meaning defined at sense 1

Time Traveler
The first known use of placenta was in 1638

Dictionary Entries Near placenta

Cite this Entry

“Placenta.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/placenta. Accessed 14 Apr. 2024.

Kids Definition

placenta

noun
pla·​cen·​ta plə-ˈsent-ə How to pronounce placenta (audio)
plural placentas or placentae -ˈsent-ē How to pronounce placenta (audio)
: the organ in most mammals by which the fetus is joined to the uterus of the mother and is nourished
placental
-ˈsent-ᵊl
adjective

Medical Definition

placenta

noun
pla·​cen·​ta plə-ˈsent-ə How to pronounce placenta (audio)
plural placentas or placentae -ˈsent-(ˌ)ē How to pronounce placenta (audio)
: 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

More from Merriam-Webster on placenta

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