The primary role of the nervous system is to coordinate and regulate the body's responses to internal and external stimuli, enabling communication between different body parts. It consists of the central nervous system (CNS), which includes the brain and spinal cord, and the peripheral nervous system (PNS), which comprises all other neural elements. The nervous system is responsible for processing sensory information, controlling voluntary and involuntary movements, and facilitating higher cognitive functions such as thinking and memory. By transmitting electrical signals, the nervous system plays a crucial role in maintaining homeostasis and overall bodily function.