endoderm One of three so-called germ layers of tissue formed in the early development of a fertilized ovum (egg). It is the innermost layer of the blastula and later differentiates into the epithelium of the liver, pancreas, gastrointestinal tract, and respiratory system. Other germ layers are the ectoderm and mesoderm. Related category • DEVELOPMENTAL BIOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |