This document discusses pathology of the central nervous system (CNS). It describes the principal cell types of the CNS including neurons, glial cells, meningothelial cells, and microglia. It outlines features unique to the CNS such as being enclosed in bone and relying on glucose and oxygen. Pathologic reactions of neurons and glial cells are described for conditions like acute injury, degeneration, and protein aggregation. Types of cerebral edema like vasogenic and cytotoxic edema are also summarized. Common CNS disorders, injuries, and bleedings are briefly outlined.