Three dimensional study of the rat urinary bladder in states of contraction and distension.

A qualitative and quantitative study of the apical surface of the superficial cells of the rat urinary bladder was made when the bladder was in states of contraction and distension. The study was performed with the scanning electron microscope. Qualitatively, no significant changes were observed with respect to the regional cell topography analyzed (fundus, body and neck of bladder) and only a progressive disappearance of folds and grooves with a more pronounced flattening of the poligonal luminal cell surface was apparent as distension increased. The quantitative data found point to significant differences between the cell populations analyzed, in particular the hexagonal cells, both at regional level and with respect to the state of contraction-distension of the urinary bladder. Isolated immature cells can be seen occupying the area left by desquamated cells that have different shapes, sizes and morphological characteristics to the mature cells.