Transitional epithelium is seen in the mucous membrane of the excretory passages of the urinary system.
The cells are often divided into three groups: the basal polyhedral cells, the intermediate pear shaped or pyriform cells with their broad, end towards the free surface and flattened or umbrella like surface squamous cells.
This epithelium accommodates itself to cover larger or small areas. Completely covering the small areas; cells are six or more layers. Covering a large area, the cells may be two or three layers only.
The cells are held together by viscous cement which permits gliding over of cells on one another.
