Which hormone stimulates the contraction of the gallbladder?

Cholecystokinin (CCK) is the hormone that stimulates the contraction of the gallbladder, promoting the release of bile into the duodenum. When fatty acids and amino acids enter the small intestine, CCK is secreted by enter endocrine cells in the intestinal mucosa. This hormone increases the motility of the gallbladder, allowing it to contract and release stored bile, which is crucial for the digestion and absorption of dietary fats.

Understanding the role of CCK provides insight into how hormonal regulation of digestion occurs. In addition to stimulating gallbladder contraction, CCK also influences pancreatic enzyme secretion, facilitating further digestive processes. This makes CCK essential in the coordination of digestive functions post-ingestion of food.

Other hormones mentioned, such as insulin, secretin, and gastrin, have distinct roles in digestion but do not primarily regulate gallbladder contraction. Insulin mainly regulates glucose metabolism; secretin stimulates pancreatic bicarbonate secretion to neutralize gastric acid; gastrin mainly stimulates gastric acid secretion in the stomach. These functions illustrate the specificity and intricacy of hormonal actions within the digestive system.