What Do Ovaries Look Like?

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The ovaries are egg-producing glands that are part of the female reproductive system. The ovaries are about the size and shape of an almond, and they sit just above the fallopian tubes—one ovary on each side of the uterus.

This article discusses the anatomy and function of ovaries, as well as conditions that affect these glands. It also shows what an ovary looks like.

Woman consulting with her gynecologist in the gynecologist's office
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Anatomy

The ovaries are a pair of glands in the female reproductive system responsible for producing eggs and the sex hormones progesterone and estrogen. They are solid structures (around the size and shape of an almond) located on each side of the uterus. They are held loosely in place within the pelvis by peritoneal ligaments.

The ovary consists of an outer cortex and an inner medulla. Embedded within the cortex are many ovarian follicles—tiny fluid-filled sacs where eggs grow. The medulla is made up of loose connective tissue containing blood vessels, lymphatic vessels, and nerve fibers.

Function

The main function of the ovaries is to develop and release mature eggs and produce sex hormones for menstruation and pregnancy.

Ovarian Follicles

At birth, a female baby has about 1 million ovarian follicles. Each ovarian follicle contains a hollow ball of cells with an immature egg in the center.

During childhood, approximately half of the ovarian follicles are absorbed by the body. By the time of puberty and the beginning of an individual's menstrual cycle, only about 400,000 ovarian follicles are left to develop into mature eggs.

Although only one egg usually fully matures during each ovulation, between 10 and 20 follicles begin the process of maturation monthly. The excess ovarian follicles are reabsorbed before ovulation occurs.

Is it possible for both ovaries to release an egg in the same cycle?

Yes. Normally, only one egg is released during ovulation, but it is possible for both ovaries to release an egg at the same time. If both those eggs become fertilized, they may result in fraternal (nonidentical) twins.

Ovulation

Around the middle of the menstrual cycle (typically day 14 of a 28-day cycle, though this timing may vary), the process of ovulation is initiated.

The steps of ovulation are as follows:

  • A decrease in estrogen (mostly estradiol) and secretion of gonadotropin-releasing hormone (GnRH) send a message to the pituitary gland to increase its secretion of follicle-stimulating hormone (FSH).
  • The increase in FSH causes the growth of 10–20 ovarian follicles (immature eggs).
  • Estrogen is secreted by some of the cells in the follicle and progesterone is produced by the cells in the ovarian follicles shortly before ovulation occurs.
  • Just before ovulation occurs, the follicle that contains the maturing egg eases toward the surface of the ovary.
  • Once the matured egg reaches the ovarian surface, ovulation occurs, when the follicle and the ovarian surface open, allowing the egg to drift out of the ovary.
  • After the egg is released from the ovary, it travels to the oviducts (the funnel-shaped ends of the fallopian tubes), where it begins its long journey of several days into the uterus.
  • The mature egg is moved along on its journey by wavelike muscle contractions in the fallopian tube.
  • The inner lining of each fallopian tube contains cilia, which are constantly beating microscopic hairs. These cilia are what help move the sperm toward the egg if a person has had unprotected sexual intercourse.

Conception (the fertilization of an egg with sperm) most often occurs in the part of the fallopian tube that is nearest the ovary. Five to six days are required for the fertilized egg to reach the uterus.

After ovulation, if pregnancy has not occurred, the empty follicle, called the corpus luteum, is reabsorbed into the body. If pregnancy does occur, the corpus luteum produces hormones that help to maintain the pregnancy.

Eggs that are not fertilized either disintegrate or flow out of the body (unnoticed) with vaginal secretions.

When a person reaches menopause, the ovaries stop releasing eggs and cease production of the hormone estrogen. However, they will still continue to produce testosterone alongside the adrenal glands. The ovaries become slightly smaller after menopause, but they won't disappear.

Why Do My Ovaries Hurt?

You might experience a twinge, a cramp, or some discomfort in your lower back or abdomen when ovulation occurs. Some people notice a small amount of vaginal discharge.

Ovary pain during ovulation is called "mittelschmerz," or midcycle pain. For some people, this pain is severe enough to be mistaken for an ectopic pregnancy (when a fertilized egg implants outside the uterus) or appendicitis (inflammation of the appendix, on the lower right side of the abdomen). During ovulation, some people may experience other symptoms such as breast tenderness, bloating, or headache.

How do you determine which ovary released the egg in a given cycle?

This is not usually easy to know. The simplest way to determine which ovary released the egg is by paying attention to any slight twinges of pelvic pain that may occur during your ovulation window, known as mittelschmerz. That slight pain on the right side or left side is likely the best indicator of which ovary released the egg.

Disease and Conditions

Listed below are some conditions that can affect the ovaries.

Ovarian Torsion

Rarely, an ovary can twist around the ligament that's holding it in place. This condition is known as ovarian torsion and can result in severe pain. Ovarian torsion is considered a medical emergency because the twisting (torsion) can cut off blood supply to the ovary and fallopian tube.

The initial symptoms are severe pelvic pain, typically on one side, along with nausea and vomiting. Immediate surgery is usually required to restore the blood supply and preserve the ovary.

Ovarian Cysts

Ovarian cysts are fluid-filled sacs similar to blisters that can form on the ovaries. Ovarian cysts are common during the reproductive years.

Ovarian cysts commonly form during ovulation or pregnancy. In some cases, they may result from hormonal treatments, including fertility treatments. Other causes are PCOS, endometriosis, or a pelvic infection.

Most types of ovarian cysts are harmless and go away without any treatment.

What does an ovarian cyst look like?

Ovarian cysts are sacs, usually filled with fluid, that form on or inside an ovary. They can range from 1 to 10 cm in size. Depending on the cause, ovarian cysts may have other characteristic features.

Dermoid cysts, which are made up of ovarian "germ cells," can contain teeth, hair, or fat. Persons with endometriosis can develop an endometrioma, a cyst filled with menstrual blood. Sometimes these cysts are called "chocolate cysts" because the fluid inside resembles chocolate syrup.

Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a hormonal disorder that affects an estimated 7% of all people with ovaries. It is the most common hormonal disorder among females. According to experts, the actual number of people affected by PCOS may be as high as 1 out of 10.

Many cases of PCOS are undiagnosed because the symptoms can vary from person to person. It also is often difficult to accurately diagnose. Because polycystic ovary syndrome can cause significant long-term health consequences, getting an accurate diagnosis, followed by proper treatment, is important.

Ovarian Cancer

Ovarian cancer is often called the "silent killer" because it usually doesn't cause symptoms until the disease has progressed to an advanced stage. In the United States, ovarian cancer ranks fifth in cancer deaths among women, making it the deadliest gynecological cancer.

What happens to ovaries during a hysterectomy?

Hysterectomy is surgical removal of the uterus. In about half of hysterectomies, the ovaries are removed as well, in a procedure known as an oophorectomy. This may be recommended to reduce the risk of ovarian cancer, especially if you are considered of high risk.

Fallopian Tube Damage

Fallopian tubes that have been damaged by diseases, infections, or other conditions may be scarred or damaged, which increases the risk of an ectopic (tubal) pregnancy.

Some of the causes of fallopian tube damage are pelvic inflammatory disease (PID, an infection in the upper reproductive system) and endometriosis (tissue that normally grows inside the uterus develops outside this organ). Some sexually transmitted infections (STIs) and other pelvic infections can also damage the fallopian tubes.

Summary

The ovaries are small, oval-shaped structures located on each side of the uterus. These glands are responsible for storing and releasing eggs (ova), as well as producing sex hormones for menstruation and pregnancy. Diseases and conditions that affect ovaries include ovarian cysts, polycystic ovarian syndrome (PCOS), and ovarian cancer.

Some of these conditions may require treatment. See your healthcare provider if you experience symptoms such as pelvic pain, abnormal vaginal bleeding, or irregular menstruation.

16 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Tracee Cornforth
Tracee Cornforth is a freelance writer who covers menstruation, menstrual disorders, and other women's health issues.