The three phases of gastric function includes; the cephalic phase, the gastric phase, intestinal phase. The cephalic phase is a phase that involves response to sight, smell, taste, or thought of food, vagus nerve stimulates gatsric secretion even before food is swallowed. Gastric phase involves; swallowed food and semi digested protein activates gastric activity, and the intestinal phase involves; duodenum responds to the arriving chyme and moderates gastric activity through hormones and the nervous reflexes.