Publisher Summary This chapter describes the structure of the normal adult mammalian gastric mucosa, The interior wall of the gastric mucosa is thrown into folds, rugae, or plicae gastricae, which as a rule are longitudinally oriented and sometimes branching. These folds are most prominent along the lesser curvature and are more marked in the empty stomach than in the filled one. Minor furrows divide the surface of the mucosa into irregularly outlined gastric areas, which are a few millimeters in diameter. A very large number of funnel-shaped gastric pits, foveolae gastricae, can be seen all over the mucosal surface; quite often, these pits are interconnected by tiny grooves. The gastric mucosa is divided into three different zones: the cardiac zone, the fundus-corpus zone, and the pyloric zone. These zones differ from each other with respect to the depth of the gastric pits and the organization of their glands.