What is the primary role of the gallbladder?

The primary role of the gallbladder is to concentrate and store bile. Bile is a digestive fluid produced by the liver that plays a crucial role in the digestion and absorption of fats. The gallbladder serves as a reservoir for bile, allowing it to be stored until it is needed in the digestive process. When food, particularly fatty food, enters the small intestine, the gallbladder releases concentrated bile, which aids in emulsifying fats, making them easier to digest and absorb by the intestinal cells.

The options regarding the digestion of proteins, producing hormones, and filtering blood highlight functions that belong to different organs. The stomach and pancreatic enzymes primarily handle protein digestion, while hormones are produced mainly by glands like the pancreas or thyroid. Blood filtration is a key function of the kidneys, not the gallbladder. Therefore, concentrating and storing bile is the correct interpretation of the gallbladder's main function in the digestive system.