Gastritis is marked by disruption of the mucosal barrier that usually protects the stomach tissue from digestive juices and manifests in acute and chronic forms.
In acute gastritis, the gastric mucosa becomes swollen and red and undergoes superficial erosion. Superficial ulceration may lead to bleeding.
In chronic gastritis, persistent or repeated insults lead to chronic inflammatory changes and, eventually, thinning or atrophy of the gastric tissue.
Gastritis can stem from various causes, each...

The human stomach is a vital part of the digestive system, performing multiple functions. It is located within the peritoneum, a serous membrane that lines the abdominal cavity. The stomach plays a central role in processing food substances and interacts with other digestive organs through coordinated digestive processes. The stomach has a characteristic J-shape and is divided into four main regions. The cardia is the first section where the esophagus connects to the stomach and is the entry...

The human body carefully regulates the internal pH of different organs to maintain homeostasis. For example, while the blood plasma maintains a neutral pH of 7, the stomach lumen has an acidic pH of 1.5 - 3.5. The low pH of stomach lumen helps kill pathogens in the food and break down complex food molecules.
The acid-secreting gastric mucosal epithelial cells (parietal cells) lining the stomach lumen maintain the low pH in the lumen. Numerous ion transporters and channels on these parietal...

The stomach comprises several layers that work together to facilitate digestion and protect the organ. The outermost layer is called the serosa, which provides support and protection to the stomach. The muscularis externa layer is responsible for the mechanical breakdown of food by contracting and moving the stomach. The submucosa layer, located beneath the muscularis externa, contains connective tissue, blood vessels, nerves, and glands that secrete mucus and other substances essential for...

Peptic ulcers are sores on the stomach's inner lining and the upper small intestine, which are the result of disruptions in the mucosal layer that houses parietal cells which produce gastric acid, and chief cells which secrete pepsinogen.
In the antrum region, G cells secrete the gastrin hormone that binds to gastrin-cholecystokinin-B (CCK2) receptors on parietal and enterochromaffin-like (ECL) cells in the fundic glands. Simultaneously, the vagus nerve releases acetylcholine, which binds to M3...

Peptic ulcers are erosive lesions of the gastric or duodenal lining, most commonly caused by Helicobacter pylori infection. This Gram-negative, helical bacterium has adapted to survive the stomach’s acidic environment by producing urease, which converts urea into ammonia and carbon dioxide. The ammonia neutralizes gastric acid in the bacterium’s immediate environment, allowing colonization of the gastric mucosa. H. pylori attaches to mucus-secreting epithelial cells, penetrates the mucus...