The vesicocavernosus reflex: Role in the act of micturition

Abstract

The paper studies the action and clinical significance of a reflex termed ‘vesicocavernosus’ in 24 healthy volunteers (mean age 44.6 years, 15 men and 9 women). A balloon-tipped catheter was introduced into the urinary bladder and inflated with air in increments of 50 ml up to 300 ml. The response of the two cavernosus muscles to rapid vesical inflation and deflation, as well as to interruption and termination of micturition, was displayed on an EMG apparatus. The muscles contracted upon rapid vesical inflation or deflation, and upon the interruption or termination of micturition. These results were reproducible. In the male, bulbocavernosus muscle contraction seems to compress and expel the urine into the bulbous urethra. Ischiocavernosus muscle contraction helps to elevate the penile shaft. The role of the cavernosus muscles at micturition in women is unknown. The vesicocavernosus reflex could be of diagnostic significance in neurologic conditions.