What is the primary role of the gallbladder in digestion?

• A. Secretes digestive enzymes into the duodenum
• B. Stores and concentrates bile
• C. Absorbs nutrients
• D. Produces bile acids

Answer: (B)

Bile handling by the gallbladder centers on storage and concentration to prepare bile for fat digestion. Bile is produced in the liver and stored in the gallbladder, where water and electrolytes are removed to concentrate it. When fatty chyme enters the small intestine, cholecystokinin signals the gallbladder to contract and release the concentrated bile into the duodenum through the bile ducts. In the intestine, bile emulsifies fats, increasing the surface area for pancreatic lipase to work. The other listed roles belong to other organs: digestive enzymes come from the pancreas, nutrient absorption mainly occurs in the small intestine, and bile acids are synthesized in the liver, not the gallbladder.