The central nervous system (very often abbreviated as CNS) is comprised of the nerves that integrate the information from and coordinate the response to the rest of the nerves reaching the other parts of the body. In humans, this is comprised of the brain and the spinal cord. The rest of the nerves form the peripheral nervous system, which senses stimuli and transmits signals to the individual muscles.
The primary control functions of the central nervous system are:
- Reflex, which is generally controlled by the spinal cord;
- Automatic (such as breathing and heart rate), which is generally controlled by the brain stem;
- Voluntary, which is generally controlled by the cerebellum.
Several diseases can affect the central nervous system, such as encephalitis, polio, Alzheimer's disease, ALS, multiple sclerosis, Huntington's disease and many others. Central nervous system diseases share symptoms such as global paralysis, chorea, and changes in behavior.