How does that work?

So, if you know me on a personal level, you will quickly learn that I am the queen of TMI... I don't have the best filter or a whole lot of shame when I'm around someone I feel comfortable with. So, when two of my good friends had babies (the "normal" way, not the c-section way) within a week of each other and I went to see them, I couldn't help but sort of position the baby between my legs and marvel at the amazingness of the woman's body. I mean, seriously, these were not big babies (~7 lbers), but HOW do we do that? Yes, I've had the birds and bees talk, and I know more about pregnancy and birth (and the human body in general) than most, but still... how again?