Bladder voiding implies activation of mictional reflex. The coordination of the latter is strictly dependent on center of miction situated in encephalo. The interruption of the nervous fibers linking pons with center of miction situated in sacral spinal cord causes the appearance of vesico-sphincter dyssynergia. On the contrary, the interruption of the fibers localized above the opns causes the loss of the voluntary control of miction. Finally the lesion of sacral spinal cord or of the nervous fibers connected with it is responsible for the appearance of detrusor areflexia with reduction of the smooth sphincter activity and paralysis of the striated one.