Overview: Nearly 200 years ago, Alexis St. Martin was shot in the stomach. He was saved by local army doctor William Beaumont, but had to live out his remaining years with a gaping hole in the stomach -- allowing Beaumont to learn a lot about how human digestion works. So today we're going to walk you through that process. We'll cover how mechanical and chemical digestion start in the mouth and continues in the stomach, where it’s pummeled by acids and enzymes and turned into chyme. We will also go over the stomach’s cephalic, gastric, and intestinal phases of digestive regulation.