2.84 Understand that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves

The central nervous system, known as the CNS, consists of the brain and spinal cord, linked by nerves which send electrical impulses. The CNS is responsible for deciding a response to a stimulus. The receptors in sense organs (like the tongue, eyes, mouth, etc.) send electrical impulses to the CNS through nerves to your brain/spinal cord which will send electrical impulses back to the effector.