The outer of the three germ layers of the embryo.
The outermost layer of differentiated cells in the embryo from which the nervous system, sense organs, oral cavity, and skin eventually develop.
The outer layer of an early embryo.
In the embryo, outside layer of cells from which the nervous system, skin, special sense organs (e.g., eyes, ears), and certain other body parts arise. (The two other cell layers are the inner endoderm and the middle mesoderm.)
The outer of the three germ layers of the early embryo. It gives rise to the nervous system and sense organs, the teeth and lining of the mouth, and the epidermis and its associated structures (hair, nails, etc.).
The outer of the three germ layers of the embryo during its early development. The ectoderm develops into the nervous systems, organs of sensation, teeth and lining of mouth, and the SKIN and its associated structures such as hair and nails.
The outermost layer of the embryo’s three primary germ layers, which gives rise to various structures, including the skin.