Anatomy of the Stomach

To understand the complications that can arise as a result of stomach cancer, it's first necessary to understand the structure and function of the human stomach. The stomach's main function is to store food and continue the digestive process that begins in the mouth. The stomach doesn't absorb nutrients; that process takes place in the intestines.

Anatomy of the Stomach: Sections of the Stomach

The human stomach is located in the upper left abdomen, just below the ribs. The stomach is a hollow, sac-like organ connected to the esophagus on the upper end and the small intestine on the other end. The food you swallow passes through the esophagus into the stomach, where digestive enzymes process the food into a pasty substance called "chyme" before it moves into the small intestine.

The human stomach has five sections, which, from top to bottom, are:

1. Cardia: The cardia is the upper part of the stomach, closest to the esophagus. Cells here produce acid and pepsin, which are used in the digestive process.
2. Fundus: Cells here also produce acid and pepsin for digestion.
3. Body: The stomach body is the main part of the stomach, where food is stored.
4. Antrum: Digestive enzymes and the food are mixed together in the antrum.
5. Pyloris: The pylorus serves as a valve, controlling the amount of food and digestive enzymes that enter the small intestine.

The section of the stomach in which cancer starts affects the symptoms, treatment options and prognosis of the disease.

If a cancer starts where the esophagus meets the stomach (called the "gastroesophageal junction") or starts in the cardia and grows into the gastroesophageal junction, the cancer is staged and treated as cancer of the esophagus.

Anatomy of the Stomach: Layers of the Stomach

The human stomach has five layers, which from inner to outer are:

1. Mucosa: Mucosa is the innermost layer of the stomach, where stomach acid and digestive juices are made, and where most stomach cancers start.
2. Submucosa: Submucosa supports the mucosa. When the stomach is empty, the mucosa and submucosa are drawn together into folds called "rugae." When food fills the stomach, the rugae are flat.
3. Muscularis: Muscularis is muscle that mixes the food with the digestive enzymes and moves the food through the stomach.
4. Subserosa: Subserosa is a wrapping layer of the stomach.
5. Serosa: Serosa is the outermost wrapping layer of the stomach.

Adenocarcinomas, which account for 90 to 95 percent of stomach cancers, are tumors that start in the cells of the mucosa.

The stomach is an important organ; however, if cancer necessitates removal of the stomach, a person can live without a stomach by making lifestyle and dietary adjustments.

Resources

American Cancer Society. (2010). Stomach cancer. Retrieved February 7, 2011, from http://www.cancer.org/Cancer/StomachCancer/DetailedGuide/stomach-cancer-what-is-stomach-cancer

Kline, K. (n.d.). Stomach. Retrieved February 7, 2011, from http://www.pitt.edu/~anat/Abdomen/Stomach/Stomach.htm