placenta

noun

pla·​cen·​ta plə-ˈsen-tə 

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

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

Investigators determined that the two babies were killed not long after they were born, as one of the babies still had the placenta attached to him. —Kimberlee Speakman, Peoplemag, 8 May 2024

In the third trimester, the brain and eyes are rapidly growing, and the baby obtains DHA daily from the placenta to support this growth.1 Babies continue to accrue DHA in the central nervous system up until 18 months of age. —Lainey Younkin, Ms, Rd, Parents, 6 May 2024

The measure specifies that treatments for an ectopic pregnancy and trophoblastic tumor, a rare tumor that forms where the placenta attaches to the uterus, are not considered abortions. —Melissa Quinn, CBS News, 2 May 2024

One study found bottled water can contain 10 to 100 times more plastic bits than previously thought, while other studies have found microplastics in clouds, rain and in the placentas of pregnant people. —USA TODAY, 23 Apr. 2024

Without it, the pregnant patient risks serious infection, detachment of the placenta from the uterine wall and other complications. —Nicole Blanchard, Idaho Statesman, 22 Apr. 2024

Police records report the baby had been wrapped, along with the placenta, in a white towel and newspapers, all placed inside a white Marriott Hotel plastic bag. —Kayla Jackson, The Arizona Republic, 13 Apr. 2024

But the placenta is a richer source of stem cells, which give rise to a wider variety of tissues—from the liver, pancreas, and heart to cartilage, bone, blood vessels, blood, and muscle. —Bymeredith Wadman, science.org, 1 Apr. 2024

Within the last year, maps of blood vessels, tumors, placenta, kidney and intestine, among other tissues, were published in high-profile journals. —Quanta Magazine, 13 Dec. 2023

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

Kids Definition

placenta

noun

pla·​cen·​ta plə-ˈsent-ə 

plural placentas or placentae -ˈsent-ē 

: 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 

plural placentas or placentae -ˈsent-(ˌ)ē 

: 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