Illustration of a typical gastric parietal cell, which secretes hydrochloric acid. Also called acid cell, or oxyntic cell. The gastric acid is secreted into large cannaliculi, deep invaginations of the plasma membrane which are continuous with the lumen of the stomach. The epithelium of the stomach is intrinsically resistant to the corrosive effects of gastric acid, however excessive secretion can lead to gastritis, gastric ulcers, and peptic acid disease. The parietal cell, and its mechanism has been studied extensively for this reason, and has resulted in the development of many drugs that act to supress the production or secretion of gastric acid.