GIT Module 301: Histology of the Stomach

Vocabulary flashcards covering stomach histology, including region-specific mucosal features, fundic and pyloric gland cell types, cellular ultrastructure, and gastroesophageal junction transitions.

Gastric Rugae

Longitudinal folds formed by the mucosa and submucosa of an empty stomach that allow for distension when the stomach fills with food.

Fundic Glands

Simple branched tubular glands arranged perpendicular to the surface that are long, crowded with minimal connective tissue, and occupy most of the mucosal thickness in the fundus and body.

Surface Mucous Cells

Tall columnar epithelial cells lining the lumen and gastric pits that feature basal oval nuclei and apical vacuolated cytoplasm, responsible for secreting a thick, adherent, viscous, and highly alkaline mucous layer for lubrication and protection against acid.

Mucous Neck Cells

Low columnar cells located in the neck region of fundic glands with round nuclei and apical vacuolated cytoplasm that secrete a mucous product that is less alkaline than that of surface mucous cells.

Undifferentiated Stem Cells (Gastric)

Low columnar cells with basal oval nuclei, basophilic cytoplasm, and mitotic figures located in the isthmus and neck of fundic glands that divide and differentiate to replace surface mucous cells (turnover of 4 to 7 days) and deeper gland cells.

Parietal (Oxyntic) Cells

Large rounded or pyramidal cells with central rounded nuclei and intensely acidophilic cytoplasm (due to abundant mitochondria) located mainly in the upper half of fundic glands that secrete Hydrochloric acid (HCL) and Intrinsic factor.

Intracellular Canaliculi

Deep invaginations of the apical cell membrane in parietal cells lined with microvilli that expand the cell surface area available for active ion transport.

Tubulovesicular System

A network of membrane-bound vesicles in parietal cells containing proton pumps that serves as a reservoir for apical cell membrane during acid secretion.

Active vs. Resting Parietal Cell

In the resting state, parietal cells feature short intracellular canaliculi, few short microvilli, and many tubulovesicular vesicles; when activated, they display deep intracellular canaliculi, numerous long microvilli, and few or no tubulovesicular vesicles.

Intrinsic Factor

A glycoprotein secreted by parietal cells that is essential for the absorption of vitamin B12 in the small intestine.

Chief (Zymogenic / Peptic) Cells

Pyramidal cells located mainly in the base of fundic glands featuring basal basophilia and apical acidophilic granules (zymogen granules) that secrete pepsinogen and gastric lipase.

Enteroendocrine Cells (APUD Cells)

Epithelial cells with endocrine functions located mainly at the base of gastric glands that belong to the diffuse neuroendocrine system (DNES) and possess electron-dense basal secretory granules.

EC Cells

A sub-type of enteroendocrine cells in the stomach mucosa that secretes serotonin to increase gastrointestinal motility.

Pyloric Glands

Coiled simple branched tubular glands located in the pyloric lamina propria that are short, less crowded, open into wide and deep gastric pits, and are lined primarily by mucous secreting cells and G cells.

G Cells

Enteroendocrine cells in the pyloric glands that produce gastrin, a peptide hormone that stimulates Hydrochloric acid (HCL) secretion by parietal cells.

Pyloric Sphincter

A anatomical circular sphincter formed by a prominent thickening of the middle circular smooth muscle layer of the muscularis externa in the pylorus.

Gastroesophageal Junction

The histological boundary where the non-keratinized stratified squamous epithelium of the esophagus transitions abruptly into the simple columnar mucous secreting epithelium of the stomach.