Final answer:
The hormone responsible for stimulating the secretion of stomach HCl and enzyme activity is gastrin, which is produced by enteroendocrine G cells in response to the presence of proteins. Gastrin facilitates the digestion process by activating parietal cells to release hydrochloric acid (HCl) and enzymes that break down protein. Its secretion is regulated by a negative feedback mechanism involving somatostatin to control stomach acidity levels.
Step-by-step explanation:
The hormone produced by enteroendocrine G cells that stimulates stomach HCl and enzyme activity is gastrin. Gastrin is an essential digestive hormone, secreted by the G cells located in the mucosal lining of the stomach. These G cells release gastrin in response to the presence of proteins within the stomach. Once released, gastrin stimulates the parietal cells in the stomach lining to secrete hydrochloric acid (HCl), which plays a pivotal role in protein digestion by denaturing the protein structures and activating digestive enzymes.
In addition to its role in stimulating acid secretion, gastrin also influences the enzyme activity within the stomach, ensuring the efficient breakdown of food into nutrients that can be easily absorbed in the intestines. This overall process ensures that the food we consume is adequately processed for nutrient absorption and waste elimination. Other related hormones in the digestive system include secretin, cholecystokinin (CCK), and gastric inhibitory peptide, all of which help coordinate various aspects of digestion.
The control of gastric acid secretion is measured through a negative feedback system involving another hormone called somatostatin. When the stomach is emptied, there is no need for a highly acidic environment, so somatostatin is released to inhibit further HCl release, therefore protecting the stomach lining and conserving energy. Thus, the actions of gastrin are carefully regulated to maintain an optimal digestive process.