The answers to this are brain and the spinal cord. It is the brain and the spinal cord that makes up the central nervous system. These body parts are very important in helping people function properly. It is the spinal cord that will act as the bridge of the nerves and messages going to and from the brain.
The brain, on the other hand, is in charge or processing everything. Those who are not in their right mind will find it harder to process thoughts or even to do some actions. Some are born with mental incapacity to do different actions that normal people can do. There also others whose mental capacities deteriorate with age or disease.