The stomach is a hollow organ in the upper abdomen, under the ribs.

It's part of the digestive system. Food moves from the mouth through the esophagus to the stomach. In the stomach, the food becomes liquid. Muscles in the stomach wall push the liquid into the small intestine.

The wall of the stomach has five layers:

• Inner layer or lining (mucosa): Juices made by glands in the inner layer help digest food. Most stomach cancers begin in this layer.
• Submucosa: This is the support tissue for the inner layer.
• Muscle layer: Muscles in this layer contract to mix and mash the food.
• Subserosa: This is the support tissue for the outer layer.
• Outer layer (serosa): The outer layer covers the stomach. It holds the stomach in place.

This picture shows the stomach and nearby organs.

Glossary Terms

The area of the body that contains the pancreas, stomach, intestines, liver, gallbladder, and other organs.

The organs that take in food and turn it into products that the body can use to stay healthy. Waste products the body cannot use leave the body through bowel movements. The digestive system includes the salivary glands, mouth, esophagus, stomach, liver, pancreas, gallbladder, small and large intestines, and rectum.

An organ that makes one or more substances, such as hormones, digestive juices, sweat, tears, saliva, or milk. Endocrine glands release the substances directly into the bloodstream. Exocrine glands release the substances into a duct or opening to the inside or outside of the body.

The moist, inner lining of some organs and body cavities (such as the nose, mouth, lungs, and stomach). Glands in the mucosa make mucus (a thick, slippery fluid). Also called mucous membrane.

A part of the body that performs a specific function. For example, the heart is an organ.

The outer lining of organs and body cavities of the abdomen and chest, including the stomach. Also called serous membrane.

The layer of tissue under the mucosa (inner lining of some organs and body cavities that makes mucus).

The layer of tissue under the serosa (outer lining of some organs and body cavities).

A group or layer of cells that work together to perform a specific function.