One of the the easiest ways to explain how the brain communicates with the body is utilizing a common item such as a safety pin.
When everything is in alignment (such as your spine) the message from your brain can be relayed to any tissue, muscle, organ, or cell with out any interference. This allows for optimal performance for our body. The same goes for our tissue, muscle, organ, or cell to relay any sensory information back to our brain.
When there is a misalignment in our spine, it can interfere with the message from the brain to the body or body to brain. As a chiropractor our main goal is to restore the alignment in the spine to help the body communicate at its best. So that you can operate at your best!