The functions of the nervous system include detecting and interpreting sensory information, making decisions about that information, and responding to and carrying out motor functions based on those decisions. The cells responsible for these functions are neurons.

There are two divisions of the nervous system. The CNS consists of the brain and spinal cord. The peripheral nervous system is made up of cranial nerves and spinal nerves. All organs are under the control of the nervous system. Knowledge of this system is essential when assisting the physician during a neurologic exam.