Final answer:
Gastrin is a gastrointestinal hormone that helps with the timing of digestion. It is released in response to the presence of food and stimulates the secretion of gastric acid to break down food in the stomach.
Step-by-step explanation:
One gastrointestinal hormone that helps with the timing of digestion is gastrin. Gastrin is released in response to the presence of food and its main function is to stimulate the secretion of gastric acid by the parietal cells in the stomach mucosa. It plays a vital role in initiating the digestive process by triggering the release of gastric juices that help break down and digest the food in the gastrointestinal tract.
Gastrin is produced by specialized epithelial cells called endocrinocytes, which are located in the mucosal epithelium of the stomach and small intestine. When food is detected, these cells secrete gastrin into the bloodstream, allowing it to reach its target organs. Once released, gastrin stimulates the production and release of gastric acid, which is essential for the breakdown of proteins and other food components in the stomach.