Home▸Medical Technology & Imaging Physics▸The Micturition Reflex: How the Brain and Bladder Coordinate Urination

🚽 The Micturition Reflex: How the Brain and Bladder Coordinate Urination

Explore the spinobulbospinal circuit that governs bladder storage and voiding, from stretch receptors and the pelvic nerve to the pontine micturition center, and see how spinal cord injury disrupts voluntary control.

Medical Technology & Imaging Physics3DModerate60 FPS

This simulation demonstrates the complete micturition reflex circuit, showing how stretch receptor signals travel via pelvic nerve afferents to the spinal cord and pontine micturition center, how storage-phase sympathetic and pudendal activity keep the bladder closed, and how voluntary disinhibition triggers the coordinated spinobulbospinal reflex that contracts the detrusor while relaxing both sphincters.

🔬 What It Demonstrates

🎮 How to Use

Adjust bladder fill volume to see stretch receptor firing rate rise along the pelvic nerve pathway, then toggle cortical inhibition on and off to see how the pontine micturition center responds. Switch between storage and voiding phase views to compare sympathetic versus parasympathetic dominance and sphincter states, and enable the spinal cord injury mode to see how the circuit breaks down and produces detrusor-sphincter dyssynergia.

💡 Did You Know?

The pontine micturition center's coordinating signal typically completes the full storage-to-voiding transition, from disinhibition through detrusor contraction and sphincter relaxation, in well under a minute, and positive feedback from urethral flow receptors helps sustain the contraction until the bladder is fully empty.

⚙ Under the hood

physiologyautonomic nervous systembladderreflex arcspinal cordurologyneurosciencebrainstem

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install