What is the function of parietal cells in the stomach?

Parietal cells are specialized cells located in the lining of the stomach, and their primary function is to secrete hydrochloric acid (HCl). This acidic environment created by gastric acid plays a crucial role in digestion, as it helps denature proteins, activating digestive enzymes, and providing an optimal pH for enzymatic activity. Hydrochloric acid also serves to kill harmful bacteria and pathogens that may be ingested with food, thereby protecting the gastrointestinal tract and contributing to overall health.

While mucin is secreted by goblet cells to protect and lubricate the stomach lining, pepsinogen is produced by chief cells and converted into pepsin only in the presence of acid. Nutrient absorption primarily occurs in the small intestine rather than the stomach. Therefore, the function attributed to parietal cells is accurately described as the secretion of hydrochloric acid, emphasizing their key role in the digestive process.