Neurons - the basic units that make up the nervous system. All cells of the nervous system are made of neurons. Neurons are able to transmit electrical impulses throughout the body as signals that cause a response.
Brain- the control center of the body.
Spinal cord - a long, thin, tubular bundle of nervous tissue and support cells that extends from the medulla oblongata in thebrainstem to the lumbar region of thevertebral column. The brain and spinal cord together make up the central nervous system(CNS).