What is the "peripheral nervous system" and its functions?

What is the "peripheral nervous system" and its functions?

Les Weiner (Former Chair of the Department of Neurology, University of Southern California) gives expert video advice on: What are the different areas of the spinal cord, and what are their functions?; How does pain work in the nervous system? and more...

Once the spinal chord nerves leave the spinal chord, they go to the arms and the legs. They innervate the muscles, they innervate the skin. They innervate the GI tract. They have innervation of the heart, and all the internal organs. So that's the autonomic nervous system, because you don't have to think about it. So there is this central nervous system, which then gives input to the peripheral nervous system, muscle, etcetera, and then there are autonomic nerves that go to all your vital organs, visceral organs. And obviously your skin has input, because it sends messages back. So you touch something, and your peripheral nervous system allows you to know that, because you're not looking at it so you're brain can't tell you that. You don't have to look at it to know it. So your peripheral nervous system has to send it back into the spinal chord and then up to the brain for interpretation.