Ependyma is the thin epithelial membrane lining the ventricular system of the brain and the spinal cord. Ependyma is one of the four types of neuroglia in the central nervous system. It is involved in the production of cerebrospinal fluid (CSF). Ependymal Cells The ependyma is made up of ependymal cells. These are the epithelial cells that line the CSF-filled ventricles in the brain and the central canal of the spinal cord. The cells are cuboidal/columnar. Their apical surfaces are covered in a… (More on Ependyma)