Meredith: (closing voiceover) The human body is made up of systems that keep it alive. There's the one that keeps you breathing and the one that keeps you standing. The one that makes you hungry and the one that makes you happy. They're all connected. Take a piece out... and everything else falls apart. And it's only when our support systems look like they might fail us... that we realize how much we've depended on them all along.