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What is atonic, automatic and autonomous bladder?

Asked by Bromley 

To understand these terms, one need to understand the physiology of micturition reflex: https://epomedicine.com/medical-students/micturition-reflex/

1. Atonic bladder:
  • Injury to dorsal root leading to deafferentation, so that bladder distension is not perceived, and the reflex contraction of detrusor is lost.
  • Retention of urine and subsequent overflow incontinence (bladder filled beyond physiological capacity)
  • Bladder wall is stretched and thin.
  • Voluntary control of micturition is intact.
2. Autonomous bladder:
  • Both the afferent and efferent parasympathetic nerve supply to the bladder is lost and the bladder is no longer under the control of the spinal cord centers.
  • Initial flaccidity and distension of bladder, followed by periodic contractions of smooth muscle, leading to dribbling of urine.
  • Contractions lead to bladder wall to shrink and become hypertrophied.
  • Contractions are weak leading to residual urine in bladder.
3. Automatic bladder:
  • Only the inhibitory control of the higher centers is lost.
  • After a period of spinal shock, reflex contraction of the bladder is regained.
  • Bladder empties reflexly (automatically) whenever filled because the higher center control is lost.
Reference: Lippincott Illustrated Reviews Physiology By Subhasis Das
  1. Automatic bladder is upper motor neuron lesion and autonomous bladder is lower motor neuron lesion.

    1. What are uninhibited bladder and motor paralytic bladders?

  2. Suprapontine lesions cause uninhibited bladder and selective injury of motor efferent causes motor paralytic bladder.