Which hormone is released from the mucosa of the jejunum in response to fats?

Cholecystokinin (CCK) is the hormone released from the mucosa of the jejunum in response to the presence of fats in the intestinal lumen. When fatty acids and amino acids enter the small intestine, they stimulate the cells in the jejunum to secrete CCK. This hormone plays a crucial role in digestion by promoting the release of digestive enzymes from the pancreas and stimulating the gallbladder to release bile, both of which are necessary for the emulsification and digestion of fats.

CCK also helps regulate appetite by signaling satiety, making it an important hormone not only for digestion but also for energy balance. In contrast, the other hormones listed have different secretion stimuli and functions: insulin is primarily released in response to carbohydrates; gastrin primarily stimulates gastric acid secretion in the stomach; and secretin is released in response to acidic chyme in the small intestine to regulate the pH by stimulating bicarbonate release from the pancreas.