embryonic layer

embryonic layer

one of the three layers of cells in the embryo: the endoderm, the mesoderm, and the ectoderm. From these layers of cells arise all of the structures and organs and parts of the body. The endoderm and the ectoderm are the first to develop. During the third week of gestation the mesoderm arises between the ectoderm and the endoderm.
References in periodicals archive ?
Tumors found in humans may arise from these cell types; teratomas may contain tissues from all 3 embryonic layers.