Gastric pits

Gastric pits (a.k.a. foveolae gastricae) are microscopic invaginations of the simple columnar epithelium that extend from the luminal surface of the stomach into the underlying mucosa. They are lined by surface mucous cells, which secrete mucus and bicarbonate to protect the gastric mucosa from acid and digestive enzymes.

Tubuloalveolar gastric glands open into the gastric pits

Gastric pits serve as the openings of the tubuloalveolar gastric glands, allowing glandular secretions to enter the stomach lumen. The depth of the pits varies in different regions of the stomach, being relatively shallow in the fundus and body and deeper in the pyloric region.