trophoblast

American  

[trof-uh-blast, troh-fuh-] / ˈtrɒf əˌblæst, ˈtroʊ fə- /

noun

Embryology.

1. the layer of extraembryonic ectoderm that chiefly nourishes the embryo or develops into fetal membranes with nutritive functions.

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trophoblast British  

/ ˈtrɒfəˌblæst /

noun

1. the outer layer of cells of the embryo of placental mammals, which is attached to the uterus wall and absorbs nourishment from the uterine fluids

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trophoblast Scientific  

/ trō′fə-blăst′ /

1. The outermost layer of cells of the blastocyst, which attaches the fertilized ovum to the uterine wall and serves as a nutritive pathway for the embryo. The trophoblast eventually differentiates into such tissues as the amnion, the placenta, and the umbilical cord.

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Other Word Forms

• trophoblastic
  adjective

Etymology

Origin of trophoblast

First recorded in 1885–90; tropho- + -blast

Example Sentences

See Examples For:

trophoblast

I can see the trophoblast, which would normally become the placenta, enveloping the embryo.

From BBC ● Sep. 6, 2023

One is called trophoblast; it’s the tissue that would normally form placenta.

From Scientific American ● Jun. 16, 2023

Here the cells in the blastula arrange themselves in two layers: the inner cell mass, and an outer layer called the trophoblast.

From Textbooks ● Jun. 9, 2022

The trophoblast cells that grow into the lining of the uterus when the placenta first forms invade maternal vessels in the uterus and enlarge them to facilitate blood flow for the developing fetus.

From The Wall Street Journal ● Nov. 2, 2015

In a healthy pregnancy, cells that come from the embryo’s placenta—called trophoblast cells—move into the walls of the uterus and help to open up maternal arteries, thereby increasing the available blood and nutrient supply.

From Slate ● Oct. 21, 2011