Whole Mount of the Gallbladder
The upper and lower images represent whole mounts of a normal gallbladder. The upper unlabelled image shows 3 relatively indistinct layers. The irregular lumiinal surface shows the folds of the mucosa under which the invisible lamina propria runs. The layer below is the muscularis which is a poorly defined layer that consists of smooth muscle and connective tissue. The outer layer on the free wall is covered by peritoneum and hence it is called a serosa. The inner layer lacks a serosal covering and hence it is called an adventitia.
gbf = gallbladder fossa