Your answer is incorrect.  The two major categories of cells found in the nervous system are neurons and glial cells. Neurons are the functional nerve cells directly responsible for transmission of information to and from the CNS to other areas of the body. Glial cells (also known as neuroglia) provide support to the neural tissue, regulate the environment around the neurons, and protect against foreign invaders. Astrocytes are big cells in the CNS that maintain the blood-brain barrier that control the entry of fluid and substances from the circulatory system into the CNS. They also provide rigidity to the brain structure. The microglia are small, mobile, phagocytic cells.