The secretion of cholecystokinin (CCK) in the duodenum is stimulated by the presence of which components in the chyme?

• A. Vitamins and minerals
• B. Nucleic acids and fiber
• C. Fats and proteins
• D. Carbohydrates and water

Answer: (C)

Verified step by step guidance

1. Understand the role of cholecystokinin (CCK): CCK is a hormone secreted by the cells in the duodenum in response to certain components in the chyme. Its primary function is to stimulate the release of digestive enzymes from the pancreas and bile from the gallbladder to aid in digestion.
2. Identify the components in chyme that stimulate CCK secretion: CCK secretion is specifically triggered by the presence of fats and proteins in the chyme. These macronutrients require specialized enzymes and bile for digestion, which CCK helps facilitate.
3. Eliminate incorrect options: Vitamins and minerals, nucleic acids and fiber, carbohydrates and water do not directly stimulate CCK secretion. While they are important for overall digestion and absorption, they do not require the same enzymatic and bile-driven processes as fats and proteins.
4. Relate the physiological response: When fats and proteins are detected in the chyme, the duodenal cells release CCK to ensure proper digestion by signaling the pancreas to release lipase and proteases, and the gallbladder to release bile for emulsification of fats.
5. Summarize the correct answer: The secretion of cholecystokinin (CCK) in the duodenum is stimulated by the presence of fats and proteins in the chyme, as these components require additional digestive support.