Gallbladder lining. Coloured scanning electron micrograph (SEM) of the internal lining of the gallbladder. Each of the small elevations on the wrinkled surface shown here is an epithelial cell. The gallbladder stores bile produced in the liver, and releases it to aid in the digestion of fats. Waste products from the liver are stored and excreted as part of the bile stored in the gallbladder. Magnification: x125 when printed at 10 centimetres across.