Urethra

the urethra is simply the conduit through which the urine passes from the bladder with voiding. It passes through the sphincter mechanism which provides normal bladder control. In men, it is prone to scarring (so-called urethral stricture) from infection or trauma. In women, because of its close proximity to the vaginal introitus, vaginal bacteria can "move up" the urethra and into the bladder to give rise to bladder infection.