basement membrane Wikipedia:Basement_membrane cellular_component lamina densa basal lamina basement lamina A collagen-containing extracellular matrix consisting of a thin layer of dense material found in various animal tissues interposed between the cells and the adjacent connective tissue. It consists of the basal lamina plus an associated layer of reticulin fibers. Note that this term has no relationship to 'membrane ; GO:0016020' because the basement membrane is not a lipid bilayer. GO:0005604 extracellular matrix