Which structure carries both urine and semen in the male reproductive system?

The urethra serves as the passageway for both urine and semen in the male reproductive system. It is a vital tube that extends from the bladder through the penis, allowing for the excretion of urine from the urinary system and the expulsion of semen during ejaculation. The dual function of the urethra is a unique feature in males, as it facilitates the elimination of waste while also playing a crucial role in reproduction.

In contrast, the vas deferens is primarily responsible for transporting sperm from the epididymis to the ejaculatory duct during ejaculation but does not carry urine. The epididymis is where sperm mature and are stored, but it does not serve as a conduit for urine. The seminal vesicle contributes fluid to semen but is not involved in carrying either urine or semen itself.