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.
References
Crossman AR. Introduction and overview. In: Crossman AR, ed. Neuroanatomy: An Illustrated Colour Text. 7th ed. Philadelphia, PA: Elsevier Limited; 2025:chap 1.
Swartz MH. The nervous system. In: Swartz MH, ed. Swartz Textbook of Physical Diagnosis: History and Examination. 9th ed. Philadelphia, PA: Elsevier; 2026:chap 21.