Video narration
How does a bite reach your stomach when you're lying down? When you swallow, the bite passes from your throat into the esophagus, a muscular tube leading to your stomach. It may seem to simply drop through, with gravity doing the work. But gravity isn't the main driver. Muscles tighten behind the bite, then relax as the next squeeze moves it forward. These squeezes travel down the esophagus in a coordinated wave, carrying the bite toward your stomach. As each squeeze passes, the one behind it takes over, so the bite advances step by step instead of falling freely. The bite is pressed along, not simply dropped through an open tube. Gravity can assist, especially when you're upright, but the squeezes do the moving. Your esophagus carries the bite to your stomach even when you're lying down.