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Human Body Study

Ovaries

A pair of almond-shaped organs in the pelvis — the female gonads. They produce eggs and the main female sex hormones.

Female reproductive system Front-view schematic showing the mammary glands, ovaries, fallopian tubes, uterus, and the cervix and vagina; each labelled part links to its article. Female reproductive system Mammary glands the breasts, which produce milk after birth. Ovaries produce eggs and the hormones estrogenand progesterone. Fallopian tubes carry the egg toward the uterus; theusual site of fertilization. Uterus the muscular organ where a fertilizedegg implants and a fetus develops. Cervix and vagina the lower passage; the vagina is alsothe birth canal. Female reproductive system — schematic front view, not to scale.

What they produce

Section titled “What they produce”
  • Eggs (ova) — released roughly monthly from puberty until menopause.
  • Estrogen — drives female sexual development and the menstrual cycle.
  • Progesterone — prepares and maintains the uterine lining for a possible pregnancy.

How it works

Section titled “How it works”

Each ovary contains a lifetime supply of immature eggs, set before birth. Each cycle a small group begins to mature; usually only one is released — ovulation — while the others wither.

Key idea

Section titled “Key idea”

The ovary is both an egg-producing organ and an endocrine gland — and unlike the testis, its supply of sex cells is finite and decided before birth. See also the HPG axis.