The gallbladder is a pear-shaped sac lying on the visceral surface of the right lobe of the liver in a fossa between the right and quadrate lobes (Fig. 4.104). It has: a rounded end (fundus of the gallbladder), which may project from the inferior border of the liver; a major part in the fossa (body of the gallbladder), which may be against the transverse colon and the superior part of the duodenum; and a narrow part (neck of the gallbladder) with mucosal folds forming the spiral fold.