Final answer:
Parietal cells release hydrochloric acid and intrinsic factor. G cells release gastrin. ECL cells release histamine. D cells release somatostatin.
Step-by-step explanation:
Parietal cells, also known as oxyntic cells, release hydrochloric acid (HCl) and intrinsic factor. HCl plays a crucial role in activating the protein-digesting enzyme pepsin and killing bacteria in the stomach. Intrinsic factor is necessary for the absorption of vitamin B12 in the small intestine.
G cells, also known as enteroendocrine G cells, release the hormone gastrin. Gastrin stimulates the secretion of gastric acid and increases the motility of the stomach, promoting digestion.
ECL cells, or enterochromaffin-like cells, release histamine. Histamine plays a role in regulating the secretion of gastric acid.
D cells release somatostatin, a hormone that inhibits the release of gastric acid.