Gastric secretion refers to the production of digestive fluids in the stomach, primarily composed of hydrochloric acid, pepsinogen, and mucus. These substances help break down food, kill harmful bacteria, and protect the stomach lining from acid damage. The secretion process is regulated by various factors, including the presence of food, hormones, and the nervous system. The main cells involved in gastric secretion are parietal cells, which produce hydrochloric acid, and chief cells, which secrete pepsinogen. When food enters the stomach, it stimulates these cells to release their contents, facilitating digestion and nutrient absorption. Proper gastric secretion is essential for overall digestive health.