What are the folds in the gall bladder for?

The folds in the gallbladder, known as rugae, serve to allow for expansion and contraction as the gallbladder fills with bile and subsequently empties into the small intestine. These folds help increase the surface area of the gallbladder, facilitating efficient storage and concentration of bile. Additionally, they assist in the organ's ability to accommodate varying volumes of bile, ensuring proper digestive function.