Peripheral Autonomic Influence on the Motility of the Urinary Bladder in the Cat: II. ‘Tone’

Parasympathetic and sympathetic influence on the“tone” of the bladder was revealed through alterations in the slope of the pressure‐volume records (cystometrograms) following partial and complete section of the autonomic nerve supplies to the vesical wall. When all bladder nerves but the efferent parasympathetic fibres were cut bilaterally, a marked elevation of vesical tone was noted. By additional section of the efferent parasympathetic supply (total extrinsic denervation) this increase in the tone of the bladder was completely abolished. A moderate decrease in vesical tone primarily ensued by section of the parasympathetic supply alone, leaving the sympathetic innervation intact. After additional sympathetic denervation, thereby depriving the bladder of all extrinsic nerves, vesical tone again increased close up to normal levels. Thus, the tone of the urinary bladder was shown to be under influence of excitatory parasympathetic and inhibitory sympathetic effects.