Body of the Stomach

The body of the stomach, also called the corpus, is the central and largest region of the stomach, situated between the fundus and the pyloric region. It serves as the main site for mechanical digestion and chemical breakdown of food through muscular contractions and the secretion of gastric juices. Most of the stomach's acid and digestive enzymes are produced in this region, making it a vital component of the upper gastrointestinal tract.

Structure

The body of the stomach has a characteristic hollow, curved morphology. Internally, its surface is lined with thick gastric folds called rugae, which allow expansion after food intake. Like other parts of the stomach, it consists of the following layers:

• Mucosa: Contains gastric glands that are densely packed and deep, rich in parietal cells (secreting hydrochloric acid and intrinsic factor) and chief cells (secreting pepsinogen).
• Submucosa: Loose connective tissue that contains blood vessels, lymphatics, and nerves.
• Muscularis externa: Includes three smooth muscle layers: inner oblique, middle circular, and outer longitudinal. These layers work in a coordinated manner to churn and propel stomach contents.
• Serosa: A smooth, slippery outer layer derived from the visceral peritoneum.

Gastric Glands

The glands in the body are often referred to as oxyntic glands. They contain:

• Parietal cells: Secrete HCl and intrinsic factor
• Chief cells: Produce pepsinogen, which is activated to pepsin by acidic pH
• Mucous neck cells: Secrete mucus that protects the gastric lining
• Endocrine cells: Including enterochromaffin-like (ECL) cells, which secrete histamine to stimulate acid secretion

Location

The body of the stomach lies in the upper left quadrant of the abdomen and spans:

• Inferior to the fundus
• Superior to the pyloric antrum
• Posterior to the anterior abdominal wall, partially obscured by the left lobe of the liver
• Anterior to the pancreas and lesser sac

It extends medially between the lesser curvature and laterally toward the greater curvature, forming the main cavity of the stomach.

Function

The body of the stomach is responsible for several crucial digestive functions:

• Mechanical digestion: The muscular wall mixes ingested food with gastric secretions through peristaltic contractions, forming a semi-liquid mass called chyme.
• Chemical digestion: Acidic secretions begin protein digestion, denature pathogens, and activate digestive enzymes like pepsin.
• Enzyme production: Chief cells release pepsinogen, while parietal cells secrete hydrochloric acid and intrinsic factor necessary for vitamin B12 absorption.
• Storage: Temporarily holds ingested food while regulating the pace of gastric emptying through the pylorus.

Clinical Significance

The body of the stomach is central to various gastrointestinal diseases and procedures:

• Gastritis: Inflammation of the mucosa in this region may result from Helicobacter pylori infection, NSAID use, or autoimmune mechanisms.
• Gastric ulcers: Often occur along the lesser curvature of the body due to acid damage and reduced mucosal defense.
• Adenocarcinoma: A common site for gastric cancer, especially in regions with high H. pylori prevalence.
• Gastrectomy: Partial or subtotal gastrectomy procedures involve resecting portions of the body and require careful preservation or reconstitution of digestive continuity.
• Endoscopy: Visualization of the gastric body is a routine part of upper endoscopy for biopsy, tumor screening, and ulcer evaluation.

The gastric body’s histological and functional integrity is essential for effective digestion. Damage to the parietal cells in this region can lead to hypochlorhydria or achlorhydria, impairing protein digestion and intrinsic factor production — both of which are crucial in nutrient absorption.