Did you know that the average human male produces as many as 12 trillion sperm over his lifetime, yet fathers just a few children?  Sperm are manufactured inside the two testicles, in a process know as spermatogenesis.  All day long, sperm-producing cells in the testes undergo cell division, regardless of the intensity of a male’s sex life.  It takes approximately 90 days for newly created sperm to wind their way through tubes in the testis and scrotum and reach a waiting area outside the testes in the part of the epididymis known as the cauda (tail) until they are ejaculated.

If the male is  not sexually active, excess sperm cells continue to leak from the storage area and are normally lost in the urine.  During the final moment of ejaculation, when catapulted forward at speeds up to 20 inches per second, as many as 400 million sperm roller coaster some 20 inches through the vas deferens and urethra before landing at the female cervix.   A few thousands speed toward the fallopian tubes at the far end of the uterus, where the egg lies in wait after drifting down from the ovaries, but only about 200 reach its surface.