“The nervous system is your body’s information processing and communication system. It receives messages, processes information, and then sends signals to the rest of your body telling it what to do.  Your brain is like the central processing unit (CPU) in a computer.  Your spinal cord is a long tube of nerves like a thick electrical cable. The central nervous system is the brain and spinal cord. The nerves outside the brain and spinal cord are called the peripheral nervous system, which further breaks down into other sub systems.  Although nerve fibers and their signals act a lot like a wire carrying electrical signals, that’s not exactly right. Nerve cells really send their signals using chemicals. “

MERCK