detrusor urinae

The detrusor urinae muscle is the major smooth muscle coat of the urinary bladder. It is responsible for emptying the bladder when it contracts. This powerful muscle is crucial for urination, working in conjunction with muscular sphincters that control the bladder's exit.1

The process of urination involves the detrusor muscle contracting, while the bladder neck and the opening to the urethra relax, allowing urine to be expelled. Nerve signals from the parasympathetic nervous system are the primary motor supply to the detrusor, causing it to contract and initiate emptying. The bladder's capacity is variable, and the detrusor muscle's contraction is essential for expelling urine. Damage to the nervous control of the bladder can lead to various disorders of urine flow, affecting the detrusor's ability to function properly.213