Which type of gastric acid secretion contributes the most during the gastric phase?

During the gastric phase of digestion, the secretion of gastric acid is significantly enhanced due to the presence of food in the stomach. This phase is primarily triggered by distension of the stomach wall and the presence of peptides and amino acids, which stimulate the gastric mucosa to secrete more gastric acid (hydrochloric acid) and pepsinogen.

The secretion processes occurring during the gastric phase are primarily mediated by the hormone gastrin, which is released from G cells in the gastric antrum in response to these stimuli. Increased gastric motility and the production of gastric juice play a crucial role in the breakdown of food, which is essential for effective digestion and preparation for nutrient absorption in the subsequent phases.

While the cephalic phase initiates gastric acid production in anticipation of food intake, it is the gastric phase that sees the highest volume of acid secretion. The intestinal phase primarily regulates digestive secretions as the chyme enters the duodenum, and the baseline phase is not a significant contributor when food is present in the stomach. Therefore, the gastric phase is correctly identified as the stage that contributes the most to gastric acid secretion during digestion.