Anatomy of the Ovaries and Some Related Common Conditions

What Is an Ovary?

The ovaries are the reproductive organs of women. One ovary is on either side of the uterus in the pelvis. These glands have three crucial functions: secrete hormones, safeguard the eggs the female is born with, and release eggs for fertilization.

What Is the Location, Size, and Shape of Ovaries?

Females are born with two ovaries on each side of the uterus. Ovaries are just long bundles of tissue before puberty. The ovaries mature along with the female. Each ovary is a solid, oval structure that is about the size and shape of an almond, measuring 3.5 cm in length, 2 cm in width, and 1 cm in thickness. One on either side of the uterus, the ovaries are situated in little depressions on the lateral walls of the pelvic cavity known as ovarian fossae. Ligaments attached to the uterus hold them in place. The uterus, where each month the released egg is fertilized, is connected by the fallopian tubes to the ovaries.

What Are the Functions of Ovary?

The ovaries have three primary functions-

• Protection of the Eggs Females Are Born With- At the midpoint of each menstrual cycle, the ovaries release an egg (oocyte). Only one oocyte from each ovary is released during each menstrual cycle, with each ovary taking turns releasing an egg.

  • A female baby is born with her entire lifetime's worth of eggs. This amount is expected to be over two million, but by the time a female enters adolescence, her ovaries have only about 400,000 eggs. Only roughly 400 to 500 eggs attain maturity from puberty until menopause.

  • All eggs are originally contained in a single layer of cells known as a follicle in the ovary, which serves to sustain the egg. One of these eggs is released from the ovary during each menstrual cycle as they mature over time.

• Production of Oocytes (Eggs) For Fertilization- An egg matures inside an ovary every month during a woman's menstrual cycle. It develops in a follicle, which is a small sac. When an egg matures, the follicle opens, and the egg is released.

  • Ovulation- Ovulation is the process through which an egg moves from the fallopian tube to the uterus for fertilization.

  • The uterus has been prepared for this, as progesterone levels stimulate the uterus lining to thicken during the menstrual cycle, making it ready to accept an egg.

  • The corpus luteum produces this progesterone (a clump of cells that develops from an ovarian follicle after a mature egg is released and secretes progesterone; it is yellow in color).

  • If the egg is not fertilized nine days after ovulation, the corpus luteum degenerates, progesterone production ceases, and menstruation begins. The uterine lining degrades, flushing the unfertilized egg out.

  • If the egg has been fertilized, the corpus luteum continues to generate progesterone, making the uterus hospitable and preventing additional egg release from the ovaries.

  • Menopause- Menopause is the term used to describe the end of a woman's reproductive years after her last menstruation. It occurs due to the loss of all remaining follicles in the ovary that produce eggs. The ovary no longer secretes the hormones estrogen and progesterone, which govern the menstrual cycle, when there are no more follicles or eggs. As a result, menstruation stops.

• Production of Reproductive Hormones- The hormones produced by the ovaries impact the growth of breasts, body hair, shape of the body, pregnancy, and the menstrual cycle.

The hormones produced by ovaries are as follows-

• Estrogen- It aids in developing the breasts and the expansion of the hips, both of which are key features of female reproduction.

• Progesterone- It thickens the uterine lining and retains it in place in case of fertilization.

• Relaxin- Relaxin is a hormone that helps the pelvic ligaments loosen and stretch during delivery.

• Inhibin- Inhibin stops the pituitary gland from producing hormones.

The early half of the menstrual cycle, before ovulation, is dominated by estrogen production, whereas the second half, after the corpus luteum has developed, is dominated by progesterone production. Both hormones are necessary for preparing the uterine lining for pregnancy and the implantation of a fertilized egg or embryo.If conception takes place during a menstrual cycle, the corpus luteum retains its functionality and continues to secrete estrogen and progesterone, enabling the embryo to implant in the uterine lining and develop a placenta. The fetus begins to develop at this point.

• Women's ovaries are also a major source of testosterone, particularly after menopause.

• The ovaries also respond to FSH and LH, which are produced by the pituitary gland, a tiny organ in the brain. Each month, FSH (follicle-stimulating hormone) raises estrogen levels and induces a group of egg follicles to grow. The increasing estrogen level will induce the LH (luteinizing hormone) to surge, inducing ovulation, when one follicle becomes dominant and matures.

What Are Some Common Diseases or Conditions Affecting Ovaries?

• Any medical problem that prevents a woman's ovaries from functioning can reduce her fertility. Treatments for other illnesses, such as chemotherapy or radiotherapy for cancer treatment, might harm the ovaries.

• Premature Ovarian Insufficiency- When a woman reaches menopause, her ovaries naturally cease to function. Most women experience this around the age of 50. This is referred to as premature ovarian failure or premature ovarian insufficiency if it happens before the age of 40.

• Polycystic Ovary Syndrome (PCOS)- Polycystic ovary syndrome is the most common ovarian condition, affecting 5 % to 10 % of women of reproductive age. The follicles of a polycystic ovary mature to a particular point but ultimately stop growing and fail to produce an egg. On an ultrasound scan, the follicles are seen as cysts in the ovaries. Any anomaly that causes a loss of normal ovarian development, such as Turner syndrome, can result in the ovaries not working properly and a loss of a woman's fertility.

• Amenorrhoea- Amenorrhoea is a condition in which a woman ceases having menstrual cycles during her reproductive years. A variety of events can contribute to it. Hypothalamic amenorrhea, for example, might be triggered by a lean/athletic physique, a high amount of frequent activity, or psychological stress. Other severe conditions like thyroid hyperactivity (thyrotoxicosis) can also cause amenorrhoea.

• Ovarian Cysts- Ovarian cysts, or growths on the ovaries, are frequent and affect nearly every woman at some point in her life. The majority of women are unaware that they have one because they are rarely painful or cause concern.

• Ovarian Cancer- A cyst might turn malignant at any time. One in every 75 women may get ovarian cancer, according to the American Cancer Society (ACS). There are already available tests that can determine a woman's risk of acquiring ovarian cancer. Some women prefer to have their ovaries removed as a preventative strategy.

Conclusion

The female reproductive system comprises the ovaries. Each woman is born with two ovaries. They are oval in shape and about four centimeters long and located on either side of the womb (uterus) against the pelvic wall in the ovarian fossa. Ligaments associated with the womb hold them in place, although they are not directly connected to the remainder of the female reproductive tract, such as the fallopian tubes. The ovarian glands play an important role in hormone secretion, the protection of the eggs that females are born with, and monthly egg release.