The male reproductive system The job of the male reproductive system is to make male sex cells - sperm - and deliver them into the vagina where they have a chance of finding and fertilizing an egg cell. Sperm are microscopically tiny, and are made in huge numbers. Just before they are released from the penis (ejaculation), fluids are added from the prostate gland to provide them with energy and to stop them drying out. The fluid and sperm together is called semen. The diagram shows the parts of the male reproductive system - the genitalia. Roll your cursor over each part to find out what it does.