What is the primary external organ that releases both urine and semen?

The primary external organ that releases both urine and semen is the penis. The penis serves a dual purpose in the male reproductive and urinary systems. It is the conduit for urine to leave the body from the urinary bladder, and it also delivers semen, which contains sperm and other fluids, during sexual intercourse.

The design of the penis allows it to play this critical role in both excretion and reproduction. The urethra runs through the penis and serves as the passage for both urine and semen to exit the body, but they are expelled through this organ at different times.

Other options, such as the scrotum, vas deferens, and epididymis, are involved in the reproductive process, but they do not serve a function in the direct expulsion of both urine and semen. The scrotum houses the testes but does not participate in the release, while the vas deferens and epididymis are internal structures where sperm are transported and matured, respectively. Thus, the penis is uniquely positioned in the body to perform this dual function effectively.