layers. The muscle fibres here contract to expel bile from the gallbladder. A distinctive feature of the gallbladder is the presence of Rokitansky-Aschoff sinuses, deep outpouchings of the mucosa that can extend through the muscular layer, and which indicate adenomyomatosis. The muscular layer is surrounded by a layer of connective and fat tissue.

The outer layer of the fundus of gallbladder, and the surfaces not in contact with the liver, are covered by