Histology of StomachN

The stomach’s histology reveals four main layers adapted for mechanical and chemical breakdown of food, starting with a mucosa of simple columnar epithelium rich in goblet cells secreting protective mucus over surface mucous cells that renew rapidly to shield from acid and pepsin. Deep gastric pits lead to glands varying by region—cardiac with mostly mucus, fundic with parietal cells pumping hydrochloric acid and chief cells releasing pepsinogen, pyloric again mucus-dominant. The submucosa is loose connective tissue with vessels and nerves, muscularis externa has three smooth muscle layers for churning, and serosa covers the outside. Rugae allow expansion, and the acidic environment kills microbes while activating enzymes, but imbalances lead to ulcers when protection fails.