The Role of the striated urethral sphincter on the dynamics of micturition was studied using 4 decerebrated dogs. The voiding cycles were analyzed by pressure flow EMG and pressure flow plot studies before and after the administration of suxamethonium. In the control condition, highly reproducible reflex micturition with bladder contraction and spasmodic rhythmic sphincter contractions was demonstrated. After the administration of suxamethonium reflex micturition occurred, but there was decreased bladder emptying as well as absence of spasmodic rhythmic sphincter contractions. The striated urethral sphincter would seem to play an important role in bladder emptying of decerebrated dogs.
