What chemical stimulates the secretion of both pepsin and hydrochloric acid in the stomach?

The chemical that stimulates the secretion of both pepsin and hydrochloric acid in the stomach is gastrin. Gastrin is a hormone produced by G cells in the stomach lining and plays a crucial role in the digestive process.

When food enters the stomach, gastrin is released, leading to several important actions: it stimulates the parietal cells of the gastric mucosa to secrete hydrochloric acid, which creates an acidic environment essential for digestion and helps in the conversion of pepsinogen to pepsin. Pepsin is a proteolytic enzyme that begins the process of protein digestion in the stomach.

Additionally, gastrin also enhances gastric motility, which helps with the mixing and churning of food in the stomach. This hormone's role is vital for ensuring that the digestive process proceeds efficiently, allowing for proper absorption of nutrients later in the gastrointestinal tract.

In contrast, while acetylcholine does play a role in stimulating gastric secretions as part of the neural response to food, it does not directly regulate the secretion of pepsin and hydrochloric acid like gastrin does. Histamine, produced by mast cells in the gastric mucosa, indeed increases acid secretion but is ultimately triggered by gastrin, making gastrin the