placenta

[pluh-sen-tuh]

noun

plural

placentas, placentae 

1. 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.

2. Botany.

   1. the part of the ovary of flowering plants that bears the ovules.

   2. (in ferns and related plants) the tissue giving rise to sporangia.

placenta

/ pləˈsɛntə /

noun

1. 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 circulation See also afterbirth

2. the corresponding organ or part in certain mammals

3. botany

   1. the part of the ovary of flowering plants to which the ovules are attached

   2. the mass of tissue in nonflowering plants that bears the sporangia or spores

placenta

1. 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.

2. 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.

placenta

1. 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.

Other Word Forms

• placental adjective
• placentary adjective
• interplacental adjective
• nonplacental adjective
• preplacental adjective
• subplacenta noun
• subplacental adjective

Word History and Origins

Origin of placenta¹

First recorded in 1670–80; from New Latin: “something having a flat, circular form,” Latin: “cake,” from Greek plakóenta, accusative of plakóeis “flat cake,” derivative of pláx (stem plak- ) “flat”

Word History and Origins

Origin of placenta¹

C17: via Latin from Greek plakoeis flat cake, from plax flat

Example Sentences

She was carrying an unknown number of human placentas in a plastic bag when she was picked up, according to the police.

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“Vaccinating during pregnancy is incredibly helpful, because moms can make the antibodies and transfer those antibodies across the placenta,” Singh said.

Read more on Los Angeles Times

He also uploaded a shot of Vick's placenta, alongside images appearing to show the organ being de-hydrated and turned into pills.

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No face is visible in the images and one showed a naked woman with a placenta between her legs, with an umbilical cord still attached to it.

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The vaccines also help newborns, as antibodies generated by the mom-to-be cross the placenta, and can protect the newborn for a certain number of months, she said.

Read more on Los Angeles Times

Related Words

• sheath 
• sheet