embryonic disk

noun Embryology.

Also called embryonic shield. in the early embryo of mammals, the flattened inner cell mass that arises at the end of the blastocyst stage and from which the embryo begins to differentiate.
the blastodisk of yolky eggs.

Origin of embryonic disk

First recorded in 1935–40

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

embryonic shield in Medicine

A platelike mass of cells in the blastocyst from which a mammalian embryo develops.embryonic shield
germinal disk