Light micrograph of a section through the stomach wall. The surface epithelial cells (light pink) produce an alkaline mucus that protects the surface of the stomach from its acid contents. The stomach surface is lined with glandular mucosa that has numerous invaginations, called gastric pits, where the gastric glands open to the lumen (white, top). The gastric glands secrete enzymes and acid to digest the food. Magnification: x200 when printed at 15cm tall.