Stomach

Other Name For Stomach: Gaster
The stomach is a muscular bag, which is specialized for the accumulation of ingested food. It connects the esophagus to the small intestine. It stores the food for short time before it empties the food to the intestine. The capacity of the stomach changes with age. At birth stomach capacity is around 30ml, 1000ml at puberty and 1500ml to 3000ml in adults. The shape of the stomach varies with food content and the surrounding organs, the empty stomach is "J" shaped.

Functions of the stomach

  • Storage of food (2-3 L capacity in adult).
  • It mixes the food bolus with gastric secretions to form semifluid chyme, which pass to the duodenum quickly.
  • Stomach controls the rate of chyme delivery to the small intestine for efficient digestion and absorption
stomach relation


Location and Description
The stomach is situated in upper part of abdomen mostly under cover of the lower ribs from the left costal margin into the epigastric and umbilical regions. It is completely surrounded by visceral peritoneum (intraperitoneal).
The stomach has two orifices, two curvatures and two surfaces.

Orifices of the stomach:

  1. Cardiac orifice is joined by lower end of the esophagus. It lies behind the left 7th costal cartilage one inch from its junction with the sternum, at the level of vertebra T11. There is physiological evidence of sphincteric action at this site, but a sphincter cannot be demonstrated anatomically.
  2. Pyloric Orifice opens into the duodenum. It lies half an inch right to the median plane, at the level of lower border of vertebra L1. The position of the pyloric orifice is indicated on the surface of the stomach by a circular groove (pyloric constriction) produced by underlying pyloric sphincter and by prepyloric vein which lies in front of the pyloric constriction. Pyloric sphincter is formed by the greatly thickened middle circular muscle layer. The pyloric sphincter controls the discharge of stomach contents through the pyloric orifice into the duodenum

Curvatures of the stomach:

  1. Lesser Curvature forms the right border of stomach, which extends from cardiac orifice to the pylorus. The lesser omentum is attached to lesser curvature and the liver. The lesser omentum forms the anterior boundary of the omental foramen and contains hepatic artery, portal vein and bile duct within its lower border.
  2. Greater Curvature extends from left of cardiac orifice, over dome of fundus, and along left border of stomach to the pylorus.The gastrosplenic ligament attaches to the upper part of the greater curvature and the greater omentum attaches to its lower part.
stomach interior


Subdivision of the stomach
The stomach is subdivided into four parts

  1. Cardia is a part surrounding the cardiac orifice.
  2. Fundus is a dome-shaped part projecting upward and to the left of the cardiac orifice. The fundus is usually full of gas (forms “gas bubble” under left dome of diaphragm in a chest X-ray).
  3. Body lies between fundus and pyloric antrum. The angular incisure is a deep indentation in the lower part of the lesser curvature that marks juncture between body and pyloric part.
  4. Pyloric part extends from the angular incisure to the pylorus. It is subdivided into pyloric antrum a wide part which leads to the pyloric canal a narrow part. The pylorus, the distal, sphincteric region of the pyloric part, which controls discharge of the stomach contents through the pyloric orifice into the duodenum.

Interior Of the stomach:
It is lined by mucous membrane which, in an empty stomach, is thrown into numerous longitudinal ridges, called gastric folds or rugae. The rugae are most marked in the greater curvature and pyloric antrum. The part of the gastric lumen that lies along the lesser curvature, and has longitudinal rugae is called the gastric canal. This canal allows rapid passage of liquids to the lower part of the stomach.

Relation of the stomach

  1. Anterior – diaphragm, anterior abdominal wall, left lobe of liver.
  2. Posterior – lesser sac and pancreas (posterior surface of stomach forms anterior wall of omental bursa). The stomach bed is formed by structures forming the posterior wall of omental bursa, these are left dome of diaphragm, spleen, left kidney and suprarenal gland, splenic artery, pancreas, transverse colon and its mesocolon.

Blood Supply

  1. Right and left gastric arteries supplies the stomach on lesser curvature side.
  2. Right and left gastroepiploic arteries supply on greater curvature side.
  3. 5 to 7 short gastric artery supplies the fundus.
stomch blood supply


The veins drain into portal, superior mesenteric and splenic veins.

Lymphatic drainage: The lymph from the stomach finally drain to the coeliac lymph nodes.

Nerve supply:
Stomach is supplied by sympathetic and parasympathetic nerves

The parasympathetic nerves

  1. The anterior vagal trunk, derived mainly from the left vagus nerve.
  2. The larger posterior vagal trunk, derived mainly from the right vagus nerve.

The sympathetic nerves are derived from segments T6 to T10 of the spinal cord, via greater splanchnic nerves.

Clinical correlations/Diseased conditions

  1. Visceral Referred Pain- felt in the epigastic region (T6-T10).
  2. Pylorospasm.
  3. Congenital Hypertrophic Pyloric Stenosis.
  4. Ca Stomach.
  5. Gastrectomy.