The esophagus is the narrow tube that carries food and liquid from the mouth into the stomach. All fluids and nutrients that we eat and drink must pass through this long cylinder before reaching the stomach to begin the digestive process. In the adult, it is around 11-13 inches long (28-33 cm) and has an internal diameter around three quarters of an inch (2 cm).
The esophagus is a muscular tube. The wall of the esophagus has several layers:
The Inner layer or lining (mucosa): The lining of the esophagus is moist so that food can pass to the stomach.
Submucosa: The glands in this layer make mucus. Mucus keeps the esophagus moist.
Muscle layer:The muscles push the food down to the stomach.
Outer layer: The outer layer covers the esophagus.