Micturition is the process of removal of urine from our body. During it, parasympathetic stimulation causes the detrusor muscle to contract and the internal urethral sphincter to relax. The external urethral sphincter (sphincter urethrae) is under somatic control and is consciously relaxed during micturition. and is voluntary control is called incontinence. While the problem of loss of bladder control is called urinary incontinence.