blastocyst

views updated Jun 27 2018

blastocyst A mammalian embryo at the stage at which, after cleavage, it is implanted in the wall of the uterus. It consists of a thin-walled, hollow sphere (trophoblast) enclosing a blastocoel. Attached to the inner surface of the trophoblast at one end there is a sheet of cells that will become the embryo proper.

blastocyst

views updated May 23 2018

blastocyst (blast-oh-sist) n. an early stage of embryonic development that consists of a hollow ball of cells with a localized thickening (the inner cell mass) that will develop into the actual embryo. See also implantation.

blastocyst

views updated Jun 27 2018

blastocyst See blastula; implantation.