What structures rely on muscle action for the movemnvt of urine?

The movement of urine primarily relies on the action of smooth muscle in the walls of the ureters and the bladder. The ureters use peristaltic contractions to transport urine from the kidneys to the bladder. Once the bladder fills, its smooth muscle, known as the detrusor muscle, contracts to facilitate urination. Additionally, the external urethral sphincter, composed of skeletal muscle, allows for voluntary control over the release of urine.