Bladder detrusor muscle

The bladder detrusor muscle is the smooth muscle layer of the urinary bladder wall, essential for the physiological processes of urine storage and voiding. It remains relaxed during the filling phase to allow the bladder to expand, a state maintained by sympathetic activation of beta-3 adrenergic receptors (NIH: Anatomy, Abdomen and Pelvis, Bladder, 2023). During micturition, the detrusor contracts in response to parasympathetic release of acetylcholine acting on muscarinic M3 receptors, forcing urine into the urethra (StatPearls: Physiology, Bladder, 2023). While "Bladder detrusor muscle" is frequently cited in clinical contexts as a therapeutic target, it is an anatomical structure rather than a single molecule; pharmacological treatments actually target specific receptors or signaling pathways within the muscle cells. Common pathologies include detrusor overactivity, which leads to overactive bladder (OAB) and urge incontinence, and detrusor underactivity, which results in incomplete emptying. Current drug classes include antimuscarinics, which reduce involuntary contractions, and beta-3 adrenergic agonists, which improve storage capacity by promoting relaxation (Andersson, K. E., 2011).

Other names

Detrusor urinae muscleTunica muscularis vesicae urinariaeBladder smooth muscle

Antagonism of muscarinic acetylcholine receptors (primarily M3) to inhibit parasympathetic-mediated contraction; Agonism of beta-3 adrenergic receptors to promote sympathetic-mediated relaxation; Inhibition of presynaptic acetylcholine release via botulinum toxin (FDA: Myrbetriq, Vesicare, Botox labels).