The brain is made up of nerve cells which interact with the rest of the body through the spinal cord and nervous system. These cells relate information back to specific centers of the brain where it can be processed and an appropriate reaction can be generated. Several chemicals are also located in the brain, which help the body maintain homeostasis, or a sense of overall comfort and calm as its basic needs are met. Keeping these chemicals balanced and the nerve cells firing properly are essential to healthy brain function.