Detrusor muscle

The detrusor muscle, also detrusor urinae muscle, muscularis propria of the urinary bladder and (less precise) muscularis propria, is a smooth muscle found in the wall of the bladder. The detrusor muscle remains relaxed to allow the bladder to store urine, and contracts during urination to release urine.

Related are the urethral sphincter muscles which envelop the urethra to control the flow of urine when they contract.

In older adults over 60 years in age, the detrusor muscle may cause issues in voiding the bladder, resulting in uncomfortable urinary retention.

Urinary retention from detrusor muscle areflexia or hypotonia (autonomic neuropathy) from diabetes mellitus.

Urinary bladder dysfunction due to lesions in the central or peripheral nervous systems. Clinical manifestations differ based on the location of the lesion.

● detrusor muscle hyperreflexia (detrusor overactivity (DO)): involuntary contraction of the detrusor muscle → sensation of urgency & possible urge incontinence

● detrusor-sphincter dyssynergia (DSD): detrusor contraction with inappropriate activation of the external urethral sphincters

● detrusor areflexia: loss of bladder tone → inability to contract sufficiently for micturition