Sperm cells travel from the testis through the vas deferens, seminal vesicles, urethra and penis. Upon ejaculation, sperm enter the female reproductive tract through the vagina and cervix on their way to fertilizing an egg in the ovary. The male reproductive structures like the testis, vas deferens and seminal vesicles and the female structures like the ovaries, uterus, cervix and vagina all work together in the process of fertilization and reproduction.