Peripheral autonomic influence on the motility of the urinary bladder in the cat. II. "Tone".

Abstract

AbstractThe micturition act was found to be regulated by an antagonistic nervous influence mediated through the two peripheral autonomic pathways to the bladder. The alterations of micturition following section and stimulation of these nerves were recorded by means of a technique (Gjone and Setekleiv 1963, Gjone 1965a, b) which does not interfere with the emptying function of the bladder. By section of the parasympathetic vesical supply the micturition reflex was abolished, whereas micturition was induced by parasympathetic stimulation. In accordance with the results of previous workers, excitatory effects on micturition were thus found to be mediated by this pathway. Following primary section of the sympathetic nerves the micturition threshold was markedly reduced, and by sympathetic stimulation interruption of reflex micturition ensued. By the latter effect, not previously demonstrated, the inhibitory influence of the sympathetic nerves to the bladder, was established. The activity of the so called“internal sphincter” was studied through direct cystoscopic examination as well as by pressure recording from the outlet region. It was concluded that the smooth muscle surrounding the internal urethral orifice acts in phase with and as part of the detrusor musculature, viz., the closure of the bladder outlet is due to relaxation, and its opening is caused by contraction. In support of this view it was noted that urinary continence persisted when the musculature of 1 he bladder neck was divided by a vertical incision, whereas incomplete and prolonged emptying of the bladder ensued subsequent to this procedure.