Neurotransmitters

The human nervous system is 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 in 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 for thought processes, emotions, and other essential body functions including sleep, energy and fear.