A muscle tube
Your food pipe, or esophagus, is a stretchy tube made of muscle. It runs from the back of your throat, down through your chest, to your stomach.
In a grown-up it's about 10 inches long, a little shorter than a ruler.
It sits just behind your windpipe. Most of the time it's squished flat, and it opens up when food comes through.
Squeezing waves
Food doesn't just fall down your food pipe. Muscles in the tube squeeze behind each bite, one after another, in a wave. This is called peristalsis (pair-ih-STAL-sis).
It's like pushing a marble through a sock by squeezing the sock behind it.
Because muscles do the pushing, food goes down even when you're lying down. Astronauts in space swallow just fine with no gravity at all. Still, eating sitting up is safest!
A bite takes about 5 to 10 seconds to reach your stomach. Drinks go even faster.
Doors at both ends
Your food pipe has a ring of muscle at the top and another at the bottom. They work like doors that open to let food through and then close tight.
The bottom door keeps food and strong stomach juices from coming back up. When it doesn't close all the way, some juice can splash up and make a burning feeling in the chest called heartburn. Heartburn has nothing to do with the heart!
When you burp, that bottom door lets a bubble of swallowed air escape back up.