title: Measurement of the elasticity of the male urethral meatus by urinary drop spectrometry.
abstract: The urinary stream breaks up into drops shortly after leaving the external meatus. For normal males the frequency of the drops is related in a characteristic way to the flow rate. From this relation the elastic properties of an elastic constriction near the external meatus are calculated, using a theory of flow through distensible tubes. The elastic constriction behaves as if rigid at low flow rates, but distends elastically at flow rates above a critical value. This theoretical result is verified by observations of the stream emerging from a mechanical model, constructed with similar elastic properties. Functional meatal stenosis is associated with a lack of distensibility at the higher flow rates, which is reflected clinically in a changed relation between drop frequency and flow rate. Measurement of the relation, by the urinary drop spectrometer, offers a quick, non-invasive way of diagnosing this type of urethral obstruction.
mesh_terms: D004548:Elasticity; D006801:Humans; D008297:Male; D008954:Models, Biological; D013057:Spectrum Analysis; D014521:Urethra / Q000502:physiology* / Q000503:physiopathology; D014525:Urethral Stricture / Q000175:diagnosis* / Q000503:physiopathology; D014554:Urination