Central nervous system
The central nervous system is composed of the brain and spinal cord. Your brain and spinal cord serve as the main "processing center" for your entire nervous system. They control all the workings of your body.
Ransom BR. Organization of the nervous system. In: Boron WF, Boulpaep EL, eds. Medical Physiology. 3rd ed. Philadelphia, PA: Elsevier; 2017:chap 10.