Pontine Micturition Center
- The pontine micturition center is the primary control center for urination (micturition).
- It sends signals to the sacral spinal cord.
- Stimulates parasympathetic neurons for bladder contraction.
- Controls voluntary motor neurons for external urethral sphincter relaxation.
Spinal Cord Involvement
- The sacral spinal cord is vulnerable to damage that can affect voiding.
- Injuries between the spinal cord’s start and mid-sacral levels can prevent voluntary urination.
- This is a larger area compared to the spinal region controlling breathing.
Spinal Cord Injury and Voiding
- Spinal cord injury can lead to dyssynergia, where the bladder contracts but the sphincter remains tight, preventing urination.
- Catheterization is often necessary to manage this condition.
- Not all spinal cord injuries result in dyssynergia; incomplete injuries may preserve some control.
Higher Brain Centers and Voiding
- The prefrontal cortex determines the appropriate time and place for urination.
- It signals the pontine micturition center to initiate the voiding process.
- Strokes in this area can lead to inappropriate urination or loss of bladder control.
- Enuresis (bedwetting) can occur due to disruptions in this higher-level control.
Conclusion
- Voiding is a complex process involving multiple brain regions and spinal cord centers.
- Damage to any part of this system can result in urinary dysfunction.
- Understanding the neuroanatomy of voiding is essential for diagnosing and treating urinary disorders.