The human nervous system is arguably one of the most complex systems in nature. It is responsible for coordinating thousands of processes, from muscle contraction to crying. The center of the nervous system is the brain, which contains over 100 billion specialized cells called neurons. The nervous system also contains very important chemical messengers called neurotransmitters. The brain uses neurotransmitters to tell your heart to beat, your lungs to breathe, and your stomach to digest. Neurotransmitters are also necessary to thought processes, emotions, and other essential body functions including sleep, energy, and fear.
Clearly, a system with this much responsibility needs to function properly in order for a person to remain healthy. Unfortunately, the nervous system can be easily disrupted through a number of factors: