Binary model of bladder function. Schematic 3D sagittal view; system in normal closed mode. a Cortical binary control of OAB: afferent impulses “X” from stretch receptors “N” are reflexly suppressed cortically (white arrows). When required, the cortex activates the micturition reflex to evacuate bladder. b Peripheral binary control of continence is by a musculo‐ligamentous mechanism which responds to cortical efferents (small arrows) to stretch vagina in opposite directions to support “N” and decrease afferent impulses “X.” The three directional muscles (large arrows), forward, pubococcygeus muscle “PCM,” backward, levator plate “LP,” downward, conjoint longitudinal muscle of the anus “LMA” contract against the supporting ligaments, PUL (pubourethral) and USL (uterosacral), to stretch vagina tightly, much like the membrane of a drum. The stretched vagina supports the urine column, preventing activation of the stretch receptors “N,” decreasing afferent impulses to the cortex and premature activation of the micturition reflex (“urge to go,” urinary frequency). c Micturition: central control (white arrows) relaxes, as does PCM (broken circle) and rhabdosphincter (not shown); the posterior muscles LP and LMA open out the posterior wall of urethra (white broken lines) just prior to bladder evacuation. CX, cervix; CL, cardinal ligament; ATFP, arcus tendineus fascia pelvis. d Emptying dysfunction: weakness in the posterior muscles LP, LMA and/or the ligaments they contract against (USL), will affect the ability of LP/LMA to mechanically open the urethra (obstructed micturition), causing prolonged emptying times and slow flow, Fig. 3. However, other anatomical structures in Fig. 1, such as brain, nerve or direct muscle damage must always be considered to have a causative role.