Answer the following question given this paragraph: 

There are many other nervous system diseases. They include multiple sclerosis, Huntington’s disease, Parkinson’s disease, and Alzheimer’s disease. However, these diseases rarely, if ever, occur in young people. Their causes and symptoms are listed below ( Table below ). The diseases have no known cure, but medicines may help control their symptoms.


Q: Multiple sclerosis, huntington’s disease, parkinson’s disease, and alzheimer’s disease are example of diseases of which body system?


A:
nervous system