Damaged gallbladder tissue. Coloured scanning electron micrograph (SEM) of severely damaged epithelial tissue and cells forming the lining of the gallbladder. Some of the cells (brown-green) have died in process called apoptosis, and the epithelial layer has detached, revealing the underlying connective tissue (beige). Red blood cells (red) indicate that bleeding has occurred. This degeneration may be caused by a range of conditions, such as cancer (carcinoma) or gallstones. The gallbladder stores bile produced in the liver, and releases it to aid in the digestion of fats. Magnification: x1080 when printed at 10 centimetres across.