Just to clear up a misunderstanding.

The body does not send any signals the central nervous system e.i. the brain does this is becouse any other part of the body is incapable of sending any signals or emitting any hormones without signal from the brain. Here is my theory about the rolling this and why people say don't move. I think what gets you in to sleep is by isolating your brain from external stimuli which in this case is visual, auditory and sensory e.g. moving.