The document provides an overview of the nervous system, including its major components and cell types. It discusses the central nervous system (CNS) which includes the brain and spinal cord, and the peripheral nervous system (PNS). The two main cell types are neurons, which transmit signals, and neuroglia, also called glial cells, which provide support. Neurons communicate with each other via synapses. The document also describes the structure and function of neurons, glial cells, and myelin sheaths, as well as some terminology used in neuroanatomy.