Facts on the Human Reproductive System



  • A woman’s reproductive system is where her body stores, releases and nurtures the egg cells (ova – singular, ovum) that create a new human life when joined with a male sperm cell.
  • All the egg cells are stored from birth in the ovaries – two egg-shaped glands inside the pelvic region. Each egg is stored in a tiny sac called a follicle.
  • One egg cell is released every monthly menstrual cycle by one of the ovaries.
  • A monthly menstrual cycle starts when follicle-stimulating hormone (FSH) is sent by the pituitary gland in the brain to spur follicles to grow.
  • As follicles grow, they release the sex hormone estrogen. Estrogen makes the lining of the uterus (womb) thicken.
  • When an egg is ripe, it slides down a duct called a Fallopian tube
  • If a woman has sexual intercourse at this time, sperm from the man’s penis may swim up her vagina, enter her womb and fertilize the egg in the Fallopian tube.
  • If the egg is fertilized, the womb lining goes on thickening ready for pregnancy, and the egg begins to develop into an embryo.
  • If the egg is not fertilized, it is shed with the womb lining in a flow of blood from the vagina. This shedding is called a menstrual period.
  • A man’s reproductive system is where his body creates the sperm cells that combine with a female egg cell to create a new human life.
  • Sperm cells look like microscopically tiny tadpoles. They are made in the testes, which is inside the scrotum.
  • The testes and scrotum hang outside the body where it is cooler, because this improves sperm production.
  • At 15, a boy’s testes can make 200 million sperm a day.
  • Sperm leave the testes via the epididymis — a thin, coiled tube, about 6 m long.
  • A mature sperm cell consists of a head, where the genetic information is stored, a midsection and a tadpole-like tail, which allows it to swim rapidly towards the female egg cell.
  • When the penis is stimulated during sexual intercourse, sperm arc driven into a tube called the vas deferens and mix with a liquid called seminal fluid to make semen.
  • Semen shoots through the urethra (the tube inside the penis through which males urinate) and is ejaculated into the female’s vagina.
  • The male sex hormone testosterone is also made in the testes.
  • Testosterone stimulates bone and muscle growth.
  • Testosterone also stimulates the development of male characteristics such as facial hair and a deeper voice.