What stimulates the nervous phase of gastric secretion?

The nervous phase of gastric secretion is primarily stimulated by the activation of the vagus nerve, which responds to sensory stimuli such as taste, smell, and sight of food. When a person sees, smells, or tastes food, sensory information is relayed to the brain, which in turn triggers the vagus nerve to stimulate gastric secretions in anticipation of food entering the stomach. This phase prepares the digestive system for incoming food, enhancing the efficiency of the digestive process before food physically reaches the stomach.

While the presence of food in the stomach does stimulate gastric secretion, it is primarily associated with the gastric phase rather than the nervous phase. Acidity levels in the stomach and hormonal signals from the pancreas are involved in digestive regulation but are more closely related to the gastric and intestinal phases of secretion, rather than the initial nervous response triggered by external sensory input.