Gastric acid is produced by parietal cells (also known as oxyntic cells) in the stomach. Its secretion is a complex and energetically expensive process. Parietal cells contain an extensive secretory network (called canaliculi) from which the gastric acid is secreted into the lumen of the stomach. These cells are part of epithelial fundic glands in the gastric mucosa. The pH of gastric acid is 2-3 in the stomach lumen, the acidity being maintained by the proton pump, a H+/K+ ATPase. The parietal cell releases bicarbonate into the blood stream in the process, which causes the temporary rise ...
In hypochlorhydria and achlorhydria, the parietal cells are unable to produce the required amount of gastric acid in the stomach, potentially leading to gastroenteritis. Also the disinfectant properties of the gastric milieu are decreased, leading to an increased risk of infections of the digestive tract (such as the foodborne infection with Vibrio vulnificus).
In Zollinger-Ellison syndrome and hypercalcemia, there are increased gastrin levels, leading to excess ...
