Skip to content

The ovaries

The ovaries are part of the female reproductive system, which also includes the fallopian tubes, uterus (womb), cervix (the neck of the uterus), vagina (birth canal) and vulva (external genitals).

The ovaries are two small, walnut-shaped organs. They are found in the lower part of the abdomen (the pelvic cavity). There is one ovary on each side of the uterus, close to the end of the fallopian tubes.

Each ovary is made up of:

  • epithelial cells – found on the outside of the ovary in a layer known as the epithelium
  • germ (germinal) cells – found inside the ovaries, and eventually mature into eggs (ova)
  • stromal cells – form connective (supporting) tissue within the ovaries, and make the hormones oestrogen and progesterone.

At puberty, the ovaries begin releasing an egg (ovum) each month in a process known as ovulation. The egg travels down the fallopian tube into the uterus. If the egg is fertilised by a sperm, it will implant itself into the lining of the uterus and grow into a baby. If the egg is not fertilised by a sperm, the lining is shed and flows out of the body through the vagina. This flow is known as a period or menstruation.

The hormones oestrogen and progesterone cause ovulation and menstruation. As you get older, the ovaries gradually produce less of these hormones. When the levels of oestrogen and progesterone fall low enough, periods become irregular and finally stop. This is known as menopause. After menopause, you can’t conceive a child naturally. The ovaries also become smaller.

Click on images to enlarge

This information is reviewed by

This information was last reviewed April 2020 by the following expert content reviewers: A/Prof Sam Saidi, Senior Staff Specialist, Gynaecological Oncology, Chris O’Brien Lifehouse, NSW; A/Prof Penny Blomfield, Gynaecological Oncologist, Hobart Women’s Specialists, and Chair, Australian Society of Gynaecologic Oncologists, TAS; Dr Robyn Cheuk, Senior Radiation Oncologist, Royal Brisbane and Women’s Hospital, QLD; Kim Hobbs, Clinical Specialist Social Worker, Gynaecological Cancer, Westmead Hospital, NSW; Sonja Kingston, Consumer; Clinical A/Prof Judy Kirk, Head, Familial Cancer Service, Crown Princess Mary Cancer Centre, Westmead Hospital, and Sydney Medical School, The University of Sydney, NSW; Prof Linda Mileshkin, Medical Oncologist and Clinical Researcher, Peter MacCallum Cancer Centre, VIC; Deb Roffe, 13 11 20 Consultant, Cancer Council SA; Support Team, Ovarian Cancer Australia; Emily Stevens, Gynaecology Oncology Nurse Coordinator, Department of Obstetrics and Gynaecology, Flinders Medical Centre, SA; Dr Amy Vassallo, Fussell Family Foundation Research Fellow, Cancer Research Division, Cancer Council NSW; Merran Williams, Consumer.