Neuronal circuitry of the lower urinary tract; central and peripheral neuronal control of the micturition cycle.

A new presentation technique is introduce to describe the neuronal circuitry involved in the control of the uropoëtic system and its control mechanisms during the micturition cycle. This method is based on the preparation of flow charts and is applied to the discussion of four qualitative models which are derived from the literature. Opinions concerning the reflex arcs and supraspinal connections said to be involved in micturition and continence are different and sometimes contradictory. Little is known about supraspinal (inter)connections and their function in micturition control is still fragmentary. The control mechanisms which terminate voiding are not totally clear. Moreover, the role of the pelvic floor musculature in the control of the lower urinary tract is probably underestimated. The flow charts presented in this paper contribute to the future design of a single complete qualitative model representing the general central and peripheral nervous connections and control mechanisms. Such a model would provide an approach for future research in neuromodulation and neurostimulation of the uropoëtic system and a reduced version could be used for quantitative modelling, e.g. in neural network simulations.