The peripheral nervous system of the human body consists of two parts: the autonomic nervous system and the random nervous system. The two systems have a few overlaps, and breathing is one of them. Breathing is an unconscious action, but it can also be controlled autonomously through the brain. Many meditation exercises emphasize the breath because it is the entry point to the autonomic nervous system. Numerous cases in the medical and spiritual literature show that some people have deep control of their bodies and can control activities that are otherwise autonomous.