The new sperm travel through the epididymis, behind each testis, where they mature. The mature sperm travel through a tube called the vas deferens through the seminal vesicle, a sac near the bladder. In the seminal vesicle, semen is added. Contrary to women, who usually produce only one egg a month, men are capable of producing billions of sperm. Even though the numbers can decrease after the age of forty, men are capable of producing sperm from puberty well into life.
Men can be fathers in their eighties and nineties.
Sperm can live in the vagina, cervix, uterus and fallopian tubes for up to five days. Only a few hundred of the 250 million healthy sperm reach the egg. If no egg is available to fertilize, the sperm swim around patiently waiting to bump into one. Because there is no chemical or physical attraction of the sperm for the egg, the sperm literally must bump into the egg. These fimbria move along the ovary until a follicle containing the ripened egg is found.