What is "endoderm"

Hypoblast \Hy"po*blast\, n. [Pref. hypo- + -blast.] (Biol.) The inner or lower layer of the blastoderm; -- called also endoderm, entoderm, and sometimes hypoderm. See Illust. of Blastoderm, Delamination, and Ectoderm.

1835, from endo- + -derm. Coined by Prussian embryologist Robert Remak (1815-1865).\n

n. One of the three tissue layers in the embryo of a metazoan animal. Through development, it will produce the digestive system of the adult.

n. the inner germ layer that develops into the lining of the digestive and respiratory systems [syn: entoderm, endoblast, entoblast, hypoblast]

Endoderm is one of the three primary germ layers in the very early human embryo. The other two layers are the ectoderm (outside layer) and mesoderm (middle layer), with the endoderm being the innermost layer. Cells migrating inward along the archenteron form the inner layer of the gastrula, which develops into the endoderm.

The endoderm consists at first of flattened cells, which subsequently become columnar. It forms the epithelial lining of multiple systems.