1. Bladder is normally empty Stretch receptors in bladder wall are stimulated

2. Signals sent via pelvic nerves to S2-S3 segments of spinal cord

3. Ascending tracts send signals to higher brain centers: a) Facilitory centers (frontal cortex, pons) b) Inhibitory centers (cerebral cortex, midbrain)

4. When bladder volume exceeds physiological capacity, micturition reflex is activated

5. Brain sends orders to S2-S3 to: - Close glottis - Contract perineal muscles and diaphragm - Contract detrusor muscle - Relax external sphincter

6. Urine is voided through relaxed sphincter Micturition reflex is self-regenerative until bladder is empty

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