April 12, 2017
Gastric mucosa is the 1 mm thick mucous membrane lining the stomach and consist of 3 layers of cells, namely columnar epithelium, lamina propria and muscularis mucosae from inside out. The consistency of the surface is soft, smooth and like velvet. Towards the pyloric end of the stomach, it is pinkish in color and the remaining surface is reddish brown in color. In infants the surface is bright red in color due to increased vascularity. The surface is thinner at the cardiac end and thicker at the pyloric end and has many plaints or rugae throughout.
3 types of glands are present in the gastric mucosa. – Cardiac glands, pyloric glands and fundic or oxyntic glands. The cardiac glands contain foveolar cells which produce mucus. The fundic or oxyntic glands produce pepsinogen enzyme. The pyloric glands also secrete mucus. Parietal cells are scattered throughout the gland and they secrete hydrochloric acid. Endocrine cells are also present in the gastric mucosa. They are gastrin producing G cells (gastrin stimulates hydrochloric acid production from parietal cells), histamine and serotonin producing Enterochromaffin-like cells (histamine stimulates acid secretion and serotonin stimulates contraction of smooth muscles of stomach), glucagon producing A cells (glucagon mobilizes the glycogen in liver).
The inner surface of the mucous membrane has a peculiar honey comb appearance. The mucous cells of the surface epithelium and the gastric pits in the fundus and pylorus of stomach contains an essential iodine concentration by sodium-iodide symporter. Bicarbonate ions are also secreted by the epithelial cells which helps to neutralize the harsh acid secreted by the stomach. This bicarbonate along with the epithelial lining and mucous membrane form the gastric mucosal barrier. Bacterial infections like H.pylori, NSAIDS, and alcohol can break this barrier and cause disease like gastric ulcer, acute and chronic gastritis etc.
Disclaimer: The information given in this write-up is purely for educating the reader. It is not meant to be a substitute for any advice from a medical expert.