Comparative pathophysiology of gastric glandular disease

The orad one-half of the stomach is lined with a stratified squamous epithelium of varying thickness (309–1154 μm), which has no glandular structures, active transport mechanisms or inflammatory cells (within the epithelium and lamina propria). Intercellular tight junctions (TJ) and bicarbonate, and mucus washed up from the glandular fundus are the only squamous barrier mechanisms. Stratification of gastric contents (created by differential solid/liquid motility, dorsal salivary bicarbonate entry and ventral acid production), acts to limit squamous acid contact. The resulting relatively neutral squamous pH allows bacterial fermentation to occur, producing acetic, butyric and propionic acids (VFAs). Adequate blood supply is required for removal of VFAs and any absorbed gastric acid ...