[Structure and function of the central nervous system].

The main elements of the central nervous system are the brain and the spinal cord. It contains millions of neurons and glial cells: astrocytes, oligodendrocytes, and microglia. The main role of the CNS is to process information, analyze signals, and activate effector organs. The role of the glial cells is the creation of the blood-brain barrier, the protection and feeding of neuronal cells, antioxidant activity, and immunological control. Unbalanced glial activation may cause neurodegeneration.