CNS & PNS

Had a great acupuncture session today, and Dr. Nelson gave me a different "exercise" to do before I go to sleep at night. It's a way to "reset the Nervous System" she said. I think I wrote that correctly? A way to sleep better at night. I'm looking forward to feeling the results.
So during my run this afternoon, I was thinking of this "exercise" . It made me wonder about my little brain .   The CNS, and PNS! The brain, the spinal cord and all the nervous structures outside of that. Everything that keeps me running, biking, and swimming, laughing, and eating of course!
Here are some ramblings on our complex systems. I may not be entirely acurate on all of this, so by all means correct me.
The nervous system can be sub-divided into "three basic funtions". Sensory, Integrative, and Motor. The Sensory bit has to do with internal stimuli(ie: blood pressure) and external stimuli (ie: a raindrop on your skin). The Integrative bit processes the Sensory information.(ie perception)  Then there is Motor function. This function takes the integrated sensory information and brings about a response. Then the sensory and motor functions of the PNS can be further sub-divided into the Somatic(SNS), Autonomic(ANS), and Enteric(ENS) nervous systms! The SNS takes the external and internal information from the body and relays it to the CNS. This action is voluntary. The ANS relays information from the visceral(internal) organs to the CNS(involuntary). Then there is also the ENS. This one is involuntary also, and takes the chemical changes in the gut and relays them to the CNS. Oh boy. So now taking all of that into account, the simple acts of eating and working out, and basic daily functions, seem to be a lot of work for the body!
And all of this made me think about proprioception,  how we view the world around us,(CNS & PNS)and how it is so vitally important to continually change our external surroundings, and exercises/activities that we expose our bodies too. Essentially,  improving and changing, the way our body, and mind, perceives the environment around us.
And wouldn't you have it, hills were on my schedule today! Hills are important for power, apparently even injury prevention, and when you run or bike hills, this challenges our fitness. Hmmm, does this change the bodies external and internal stimuli as well?  Hey, even work on adjusting the running stride a little. Improve propriocetion? Which is not a bad thing to do when you run all the time any how. Why stick to the same stride that you've always known? 
With the CNS and PNS, and all the bodies daily workings, I'm looking forward to "resetting my nervous system".
The more I read about the body, the more humble it makes me.

Principles of Human Anatomy, 11th Edition, Tortora, G.J., Nielsen, M.T.