The reproductive organs of the male include the penis, urethra, prostate, ejaculatory duct, vas deferens, epididymis and testis. Unlike a woman who has a finite supply of eggs and releases one each month, a man makes sperm continuously in the testes after puberty. Testosterone is the hormone produced in the testes and the same hormones that regulate a woman’s menstrual cycle, FSH and LH, are involved in the production of both testosterone and sperm in the man. The sperm leave the testis and travel through a tube called the epididymis and then through the vas deferens where the sperm mature. During ejaculation, they move to the ejaculatory duct, where they mix with fluid from the seminal vesicles and prostate gland.
The combination of sperm and fluid is called semen. The semen is how sperm travels outside of the body. In order for fertilization to take place, a man must have a sufficient number of normal sperm that are able to travel through the woman’s vagina, to the uterus, and ultimately to the fallopian tubes to meet an egg.