membrane', adjectival: meningeal / m ə ˈ n ɪ n dʒ əl /) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in the subarachnoid space between the arachnoid mater and the pia mater.
The term mucous membrane comes from the fact that the major substance secreted from the membranes is mucus; the principal constituent of mucus is a mucopolysaccharide called mucin. mucus Surface mucous cell on the stomach lumen secreting mucus (pink stain).