urethral sphincter

The urethral sphincter is a ring of muscle that surrounds the urethra, the tube that carries urine from the bladder out of the body. Its primary function is to control the release of urine, opening to allow urination and closing to hold urine in the bladder. This muscle works consciously when you decide to urinate and also involuntarily to prevent leaks. Proper functioning of the urethral sphincter is essential for bladder control and continence.