Esophagus/Stomach Junction
Esophagus:
stratified squamous non-keratinized epithelium
Stomach:
Simple columnar epithelium
Stomach
• Cardia-
Small area of predominantly mucus secreting glands surrounding the entrance of the esophagus. Glands are less coiled than in the antral glands.The pits are shorter than the antropyloric pits.
• Fundus and body-
Major histological region. Consists of straight, tubular glands. Strands of muscularis mucosae extend between the glands from the base. The glands secrete gastric juices as well as protective mucus.
• Pylorus-
Branched glands open into deep irregular shaped pits. Composed of mucus secreting cells. Mucus secreted by pyloric glands lubricate and protect entrance to the duodenum.
Scattered ‘G’ cells (endocrine cells), secrete gastrin.
• The gastric mucosa consists of surface epithelium, gastric pits and gastric glands.
• The gastric glands extend from the muscular mucosae to extend into the stomach lumen via gastric pits.
• The foveolar cells lining the surface and gastric pits are identical throughout the stomach
Glands differ in different regions of the stomach.
Gastric pits occupy approximately 25% of the mucosa. Pits lie parallel to one another. These are separated by the lamina propria. There is more lamina propria separating the pits than between the glands.
• Types of cells present in the stomach:
Mucous secreting cells (goblet cells)-
Line the luminal surface of the stomach and gastric pits and gastric glands. Produce mucus and bicarbonate.
Mucous neck cells-
Present in the neck of the gland. Produce mucin.
Parietal cells (oxyntic cells)- Distributed throughout the length of the gland , but numerous in the middle portion. Large, rounded cells with eosinophilic cytoplasm and centrally located nucleus. Produce gastric acid.
Chief cells (peptic or zymogenic cells)-
Clustered at the base of the gland. Identified by basally located nuclei and strongly basophilic granular cytoplasm.
Produce pepsinogen, digests protein.
Stomach/Duodenal Junction
Stomach:
• Appears as flat surface w/pits
• Mostly mucous-secreting cells
• Continuous mucous-secreting glands
Duodenum:
• Plicae circulares
• Mostly absorptive cells w/goblet cells (mucous) interspersed
• Brunner’s glands in submucosa
• Individual secretory cells (goblet cells)