The oesophagus (gullet) is part of the digestive system, which is sometimes called the gastro-intestinal tract (GI tract). The oesophagus is a muscular tube. It connects your mouth to your stomach.
When you swallow food, the walls of the oesophagus squeeze together (contract). This moves the food down the oesophagus to the stomach.
The upper part of the oesophagus is behind the windpipe (trachea). The windpipe is the tube that connects your mouth and nose to your lungs, so you can breathe. Below your lungs is a layer of muscle called the diaphragm. It helps you to breathe. Most of your oesophagus sits above the diaphragm in your chest.