The document summarizes the structure and function of the nervous system. It describes that the nervous system is made up of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS contains the brain and spinal cord, while the PNS contains neurons that connect the CNS to sensory receptors and effector organs. It also explains the basic anatomy and roles of neurons, sensory and motor neurons, and reflex arcs in transmitting signals throughout the nervous system.