The basal lamina
A layer of glycoproteins and a network of fine protein filaments that functions to prevent the movement of proteins and other large molecules from the connective tissue to epithelium describes the basal lamina.
The basal lamina is an important layer of extracellular matrix, produced by the epithelial cells on which it lies. The basal lamina is made up a combination of collagens, and glycoproteins such as laminin, heparan sulphate, and entactin. The basal lamina protects the overlying epithelium by reducing the interaction between the epithelial cells and the other cells in the tissue. The basal lamina also functions as a molecular filter, thereby allowing only water and small molecules to pass through.