Electromyography of the External Anal Sphincter during Micturition and Electrophysiological Bulbocavernosus Reflex in Healthy Spayed Female Canines

Figure 4

EAS EMG during micturition. (a) Before the voiding phase, low-amplitude high-frequency bursting is exhibited. (b) At the beginning of the voiding phase, medium-amplitude low-frequency bursting is exhibited. (c) During the voiding phase, oscillate medium- and/or high-amplitude low-frequency bursting with low-amplitude high-frequency bursting is exhibited. (d) At the end of the voiding phase, high-amplitude high-frequency bursting (guarding reflex) is exhibited. The white arrow indicates the initial urine leakage and the red arrow indicates the end of urination. EAS, external anal sphincter; EMG, electromyography. (A) Zoomed window of the yellow square from (a) phase; the most prominent pattern is a low-amplitude high-frequency bursting. (B) Zoomed window from the (b) phase, a medium-amplitude low-frequency bursting at the beginning of voiding. (C) Zoomed window of the orange square from (c) phase, oscillating medium- and high-amplitude low-frequency bursting between low-amplitude high-frequency bursting during the pulsatile flow of urine. (D) Zoomed window from (d) phase; the most prominent pattern is a high-amplitude high-frequency bursting.