The ovary (from Latin ōvārium 'egg') is a gonad in the female reproductive system that produces ova;[1] when released, an ovum travels through the fallopian tube/oviduct into the uterus.

[2] Each ovary is whitish in color and located alongside the lateral wall of the uterus in a region called the ovarian fossa.

The ovaries lie within the peritoneal cavity, on either side of the uterus, to which they are attached via a fibrous cord called the ovarian ligament.

[6] The surface of the ovaries is covered with a membrane consisting of a lining of simple cuboidal-to-columnar shaped mesothelium,[7] called the germinal epithelium.

When egg cells (oocytes) are released from the fallopian tube, a variety of feedback mechanisms stimulate the endocrine system, which cause hormone levels to change.

[12] The follicle remains functional and reorganizes into a corpus luteum, which secretes progesterone in order to prepare the uterus for an eventual implantation of the embryo.

[medical citation needed] As women age, they experience a decline in reproductive performance leading to menopause.

As ovarian reserve and fertility decline with age, there is also a parallel increase in pregnancy failure and meiotic errors resulting in chromosomally abnormal conceptions.

Titus et al.[20] showed that DNA double-strand breaks accumulate with age in humans and mice in primordial follicles.

Titus et al.[20] also found that expression of 4 key genes necessary for homologous recombinational repair of DNA double-strand breaks (BRCA1, MRE11, RAD51 and ATM) decline with age in the oocytes of humans and mice.

A study identified 290 genetic determinants of ovarian ageing, also found that DNA damage response processes are implicated and suggests that possible effects of extending fertility in women would improve bone health, reduce risk of type 2 diabetes and increase the risk of hormone-sensitive cancers.

Methods such as measuring AMH (anti-Müllerian hormone) levels, and AFC (antral follicule count) can predict ovarian aging.

[medical citation needed] If the egg fails to release from the follicle in the ovary an ovarian cyst may form.

[49] The procedure is to take a part of the ovary and carry out slow freezing before storing it in liquid nitrogen whilst therapy is undertaken.

Tissue can then be thawed and implanted near the fallopian, either orthotopic (on the natural location) or heterotopic (on the abdominal wall),[49] where it starts to produce new eggs, allowing normal conception to take place.

In mammals including humans, the female ovary is homologous to the male testicle, in that they are both gonads and endocrine glands.

[52] Many of the features found in human ovaries are common to all vertebrates, including the presence of follicular cells, tunica albuginea, and so on.

Corpora lutea are found only in mammals, and in some elasmobranch fish; in other species, the remnants of the follicle are quickly resorbed by the ovary.

In birds, reptiles, and monotremes, the egg is relatively large, filling the follicle, and distorting the shape of the ovary at maturity.