basement lamina


base·ment mem·brane

an amorphous extracellular layer closely applied to the basal surface of epithelium and also investing muscle cells, fat cells, and Schwann cells; thought to be a selective filter and to serve both structural and morphogenetic functions; it is composed of three successive layers (lamina lucida, lamina densa, and lamina fibroreticularis), a matrix of collagen (of which type IV is unique to the lamina densa of this membrane), and several glycoproteins. Synonym(s): basement lamina, basilemma