2.12 – Micturition control centres

The spinal, cortical and pontine micturition control centres all work together to control micturition (urination). Find out what happens when there is damage to the micturation control centres.

1. Spinal micturition control centre

The spinal micturition control centre is between S2-S4 in the spinal cord. 

The spinal micturition control centre relays sensory information from the bladder and outgoing motor nerve impulses.

2. Pontine micturition control centre

The pontine micturition control centre is in the brain stem. It is responsible for the co-ordination of the sphincter relaxation and the detrusor contraction. It works like a ‘switch’, switching from storage to voiding and back again once the bladder is empty.

3. Cortical micturition control centre

The cortical micturition control centre is in the frontal cortex. We introduced this to you earlier this module when we were looking at bladder filling. Dementia and damage to the frontal lobe can reduce social awareness of, and the need for continence and bladder control  This produces symptoms of OAB or inappropriate voiding. 

Damage to micturition control centres

So, what can happen if there is damage to these micturition control centres?

The spinal micturition control centre is positioned low down in the spinal cord and any damage to the spinal cord above this S2-S4 level can affect the control of micturition. People with spinal cord damage often experience a reflex bladder which empties spontaneously.

Damage to the pontine micturition control centre can affect the co-ordination of the sphincter relaxation and detrusor contraction, this condition is known as detrusor sphincter dyssynergia. With dyssynergia there is a desire to void but the individual is not able to pass urine effectively as, due to a lack of co-ordination, the sphincter/pelvic floor contract at the same time as the bladder and this results in incomplete bladder emptying. This condition is common in patients with traumatic spinal injury and can produce dangerous bladder pressures. 

Lesions affecting the cortical micturition control centre can remove the cortical inhibition and result in increased bladder activity causing urgency and frequency.