What is the function of the gallbladder?

The gallbladder's primary function is to store and concentrate bile, a digestive fluid produced by the liver. Bile plays an essential role in the digestion and absorption of fats in the small intestine. When food containing fat enters the digestive system, the gallbladder releases the stored bile into the small intestine to help emulsify fats, making them easier to digest and absorb. This storing and concentrating function ensures that bile is available in sufficient quantities when it is needed for digestion.

The other functions listed do not pertain to the gallbladder. Digestive enzymes are secreted by the pancreas and not the gallbladder. Insulin production takes place in the pancreas, specifically in the islets of Langerhans, and the gallbladder does not filter blood, a function carried out by the kidneys and liver. Thus, the gallbladder's role in storing and concentrating bile is central to its function in the digestive system.