The esophagus is also called the food tube. It is the path food follows from the mouth to the stomach.

It is made of a group of muscles that pushes food down to the stomach. It is contributes to the physical changes that occur in digestion. It pushes apart the food and crushes it down.

Gravity helps the esophagus do its job. But you can still swallow, even if you stand on your head or go into space.