Say What?

Nathan has been hitting me with some tough questions lately. I honestly don't know where he gets this stuff. Most parents complain about the Why phase but I'm currently trying to survive the Hows. 

"How does your spinal cord make your joints bend so you can walk?"

"How do they make water?"

"How do wires bring electricity to your house?"

"How do babies get out of their mommy's belly?" I'm pretty sure most kids ask how the babies get into the belly. Nope. Mine wants to know how they get out!

How am I supposed to answer these? Anyone? Anyone?