- the blastula of the mammalian embryo, consisting of an inner cell mass, a cavity, and an outer layer, the trophoblast.
Origin of blastocyst
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- Also called: blastosphere the blastula of mammals: a sphere of cells (trophoblast) enclosing an inner mass of cells and a fluid-filled cavity (blastocoel)
- another name for germinal vesicle
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for blastocyst
Online Etymology Dictionary, © 2010 Douglas Harper
- The modified blastula stage of mammalian embryos, consisting of the inner cell mass and a thin trophoblast layer enclosing the blastocoel.blastodermic vesicle
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
- 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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.