Uberon definition : 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.;
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.