The urethra is the tube that transports urine (and semen, in males) out of the body. The urethra begins at the bladder in men and extends through the prostate gland, perineum and the length of the penis. In females, the urethral length is shorter and extends from the bladder to just in front of the vagina.
In Our Own Words
The urethra, or urine-carrying tube, is different anatomically in men and women. In men, the tube begins at the bladder, goes through the prostate gland and runs the entire length of the penis, carrying urine and semen out of the body. In women, the urethra is much shorter, beginning at the bladder and ending in front of the vagina.