Final answer:
Sympathomimetic drugs constrict the bladder base and urethral sphincter muscle through α1-adrenergic receptors to aid in urinary continence.
Step-by-step explanation:
Sympathomimetic drugs constrict the bladder base, prostate and urethral sphincter muscle via α1-adrenergic receptors to promote urinary continence.
These drugs act by mimicking the effects of the neurotransmitter norepinephrine, leading to increased muscle tone in these areas. The action of sympathomimetics is important in treating conditions where there is a need to improve the closure of the urethral sphincter, thereby preventing unwanted urinary leakage.