What stimulates the secretion of bile from the gallbladder?

Bile secretion from the gallbladder is primarily stimulated by Cholecystokinin (CCK). When fats and proteins enter the small intestine, CCK is released by the intestinal cells in response to the presence of these nutrients. CCK acts on the gallbladder to promote its contraction, leading to the release of stored bile into the duodenum. This bile is essential for the emulsification and absorption of dietary fats.

While other hormones play roles in digestion, they do not specifically trigger bile release. Gastrin mainly stimulates gastric acid secretion in the stomach, Secretin primarily stimulates bicarbonate secretion from the pancreas when acidic chyme enters the small intestine, and GIP (Gastric Inhibitory Peptide) has a role in insulin secretion and decreasing gastric motility but does not stimulate bile release. Thus, CCK is the key player in promoting the secretion of bile from the gallbladder in response to the presence of fats and proteins in the digestive tract.