Ectoderm: One of the three primary germ cell layers (the other two being the mesoderm and endoderm) that make up the very early embryo. The ectoderm is the outermost of the three layers. It differentiates to give rise to many important tissues and structures including the outer layer of the skin and its appendages (the sweat glands, hair, and nails), the teeth, the lens of the eye, parts of the inner ear, the nerves, brain, and spinal cord. This much is classic human embryology.
Stem cell research, however, has shown that some cells within ectodermal structures retain their ability to differentiate into other tissues. For example, some cells in brain (ectoderm) can become bone marrow (mesoderm).
Library > Literature & Language > Dictionary ( ĕk ' tə-dûrm ' ) n. The outermost of the three primary germ layers of an embryo, from which the epidermis, nervous ...
ectoderm (anatomy), the outermost of the three germ layers, or masses of cells, which appears early in the development of an animal embryo. In vertebrates, ectoderm ...
Ectoderm: One of the three primary germ cell layers (the other two being the mesoderm and endoderm) that make up the very early embryo. The ectoderm is the outermost of ...
Ectoderm, Mesoderm and Endoderm During gastrulation, three major cell lineages are being established. They are the Ectoderm (shown in the diagram as blue), Mesoderm (red ...
noun Embryology . the outer germ layer in the embryo of a metazoan. Also called ectoblast. Origin: 1860–65; ecto- + -derm Related forms ec·to·der·mal, ec·to ...