- Endoderm is the innermost of the three primary germ layers in the very early 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.
- The innermost of the three primary germ layers of the embryo; from it are derived the epithelium of the pharynx, respiratory tract (except the nose), digestive tract, bladder, and urethra.
Synonyms
Endoblast, Entoderm, Entoblast, Hypoblast