What are the two layers of the basement membrane, and what makes each layer?

1 Answer
Mar 15, 2016
  1. Basal Lamina
  2. Reticular Lamina


Most epithelial cells are separated from the connective tissue by a sheet of extracellular material called Basement Membrane. The basement membrane is usually visible with the light microscope. It is formed by the association of two layers : Basal lamina and reticular lamina. medical-dictionary.thefreedictionary.com

Basal lamina is visible only with the electron microscope, and about 20-100 nm in thickness. It consists of a delicate network of fine fibrils (lamina densa). In addition the basal lamina may have an electron-lucent layer on one or both sides of the lamina densa . This layer is called lamina rara or lamina lucida . The main components of basal lamina are type 4 collagen, the glycoproteins laminin and entacin, and proteoglycans.

Reticular lamina is fromed by reticular fibers , as the name suggests. The reticular lamina is usually thicker than the basal lamina.

Some facts on the basement membrane :