The document summarizes the structure and function of the nervous system. It has two principal parts: the central nervous system (CNS), comprising the brain and spinal cord, and the peripheral nervous system (PNS) comprising nerves. The CNS integrates sensory input and dictates motor responses, while the PNS carries signals between the CNS and sensory receptors and effector organs. Neurons are the basic functional units and transmit signals via electrical impulses. Neuroglia provide support and insulation for neurons.