blastocyst

American  

[blas-tuh-sist] / ˈblæs tə sɪst /

noun

Embryology.

1. the blastula of the mammalian embryo, consisting of an inner cell mass, a cavity, and an outer layer, the trophoblast.

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blastocyst British  

/ ˈblæstəʊˌsɪst /

noun

1. Also called: blastosphere.  the blastula of mammals: a sphere of cells ( trophoblast ) enclosing an inner mass of cells and a fluid-filled cavity ( blastocoel )

2. another name for germinal vesicle

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blastocyst Scientific  

/ blăs′tə-sĭst′ /

1. The modified blastula that is characteristic of placental mammals. It has an outer layer, known as a trophoblast, that participates in the development of the placenta. The inner layer of cells develops into the embryo.

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Etymology

Origin of blastocyst

First recorded in 1885–90; blasto- + -cyst

Compare meaning

How does blastocyst compare to similar and commonly confused words? Explore the most common comparisons:

• blastula vs. blastocyst

Example Sentences

See Examples For:

blastocyst

Prior to implantation, an embryo is a ball of about 250 cells organized as a blastocyst.

From Science Daily ● Mar. 23, 2024

A blastocyst is the early stage of an embryo, which is defined as the state of development that starts at fertilization and lasts up to eight weeks.

From Seattle Times ● Feb. 21, 2024

What about preimplantation models of human embryos that mimic the blastocyst stage of natural embryos—that is, the stage at which doctors transfer fertility-clinic embryos into a patient’s uterus?

From Scientific American ● Jul. 13, 2023

They’ve mimicked the blastocyst, the simple developmental stage that implants in the uterus, and recreated gastrulation, when embryos become multilayered.

From Science Magazine ● Aug. 2, 2022

The outer layers of the developing embryo or blastocyst grow into the endometrium by digesting the endometrial cells, and healing of the endometrium closes up the blastocyst into the tissue.

From Textbooks ● Apr. 25, 2013