Your digestive system gears up

A fresh-baked apple pie is browning in the oven. Just the sight and smell of it — and the anticipation of eating it — are enough to make you start salivating and producing stomach acids. So even before you take a bite, your digestive system has swung into action.

After the first steaming morsel enters your mouth, the many organs of your digestive tract kick into high gear. Here's a look at how your digestive system works, from top to bottom.