The Sex Organs - The Male Sex Organs

The Internal Sex Organs: The System of Genital Ducts

The Urethra
The urethra is a single tube which leads from the bladder to the tip of the penis. (The urethra should not be confused with the two ureters which lead from the kidneys to the bladder.) In the male, the urethra serves two important functions: to release either urine or semen. (Because of certain muscles, urine and semen cannot be released together.) While the urine enters the urethra directly from the bladder, the semen is composed of several different fluids which enter through special openings in the urethral wall mainly in the region of the prostate gland.