[ . . . . . man, that question. That question gets Tenka to pause as he puts his hand over the page he was on, thinking about what he's been studying for the past hour. He's not as good at studying as Sousei normally but when it counts to learn something, Tenka's not half-bad at remembering. He's done years of research on the Orochi, after all.

So he hums thoughtfully before meeting Sousei's eyes again and trying to explain as best as he can based off of what he read.]

Everything starts in your brain. [He points to his head.] Don't ask me how, but it generates... energy or electricity in the form of 'signals'. So sorta like how your phone gets signal, I think. You press a button and things happen.

So... for things to happen, they need to travel down this thing called the 'spinal cord' which runs down your back. It's pretty much aligned with your actual spine which I guess makes sense.

The electricity from your brain moves down your spinal cord and then goes out as far as your fingertips and toes. So... [He pauses, trying to think of an easy way to explain this.] It's like... you know how kids have dolls? It's like the kid had the brain behind it all and moved the doll. What you want the doll to do, it does.

What your brain wants your body to do, it does - through [he gestures to Sousei's book] 'the central nervous system'.

[ . . . . . ]

I think there's a non-central nervous system too though. Not sure what that's about.