'Science Of Kissing' Video Shows Crazy Effect Smooching Has On Your Body

Kissing feels good--no doubt about that. But why does it feel good, and what happens inside your body when you lock lips with a loved one?

The answers to those questions are surprisingly complicated, as Joe Hanson of the YouTube channel It's Okay To Be Smart explains in a new video. Kissing, he says, involves five of your 12 cranial nerves and more than a dozen facial muscles--and that's just the beginning.

"Your first kiss brings on a rush of novelty as a flood of dopamine acts on the same brain reward centers triggered by drugs like cocaine," Hanson says in the video. "Thanks to epinephrine and norepinephrine, your heart beats faster and you get a wave of oxygenated blood to your brain which makes your pupils dilate. Maybe that's why we close our eyes when we kiss."

Fascinating. Still, researchers claim there's a lot left to learn about kissing. So, this Valentine's Day you may want to run some field tests! Science needs you.