Light micrograph of gallbladder epithelium. At centre is a fold in the mucous layer, providing a thin axis of lamina propria occupied mainly by blood vessels. Overlying the lamina propria axis is a simple columnar epithelium with nuclei located in the basal third. At the apical border, the cells show a density that corresponds to a striated plate, less developed than in the intestine. The dark nuclei located near the base of the epithelium are lymphocytes.