]> bilaminar disc FMA:293863 NCIT:C34112 Wikipedia:Bilaminar_disc UMLS:C1283997 bilaminary germ disc bilaminary embryonic disc bilaminar disk UBERON:0000091 A flattened, almost circular bilaminar plate of cells formed when the inner cell mass (aka embryoblast) forms two epithelial layers, each of a distinct lineage, separated by an extracellular basement membrane: the external (dorsal) layer is called the epiblast and the internal (ventral) layer is called the hypoblast (aka primitive endoderm); together, they compose the bilaminar embryonic disc. embryonic disc embryonic shield germinal disc germinal disk http://upload.wikimedia.org/wikipedia/commons/e/e3/Gray21.png develops_from develops from develops from inner cell mass embryonic structure