ovary, ductless gland of the female in which the ova (female reproductive cells) are produced. In vertebrate animals the ovary also secretes the sex hormones estrogen and progesterone, which control the development of the sexual organs and the secondary sexual characteristics. The interaction between the gonadotropic hormones from the pituitary gland and the sex hormones from the ovary controls the monthly cycle in humans of ovulation and menstruation. There are two ovaries in the human, held in place on each side of the uterus by a membrane; each ovary is about the size of an almond. About 500,000 immature eggs are present in the cortex of the ovary at birth. Starting at puberty, eggs mature successively, and one breaks through the ovarian wall about every 28 days in the process known as ovulation, which continues until menopause, or cessation of reproductive functioning in the female. After its release from the ovary, the ovum passes into the oviduct (uterine or fallopian tube) and into the uterus. If the ovum is fertilized by the sperm (male reproductive cell), pregnancy ensues (see reproductive system). In flowering plants the part of the pistil containing the ova is called the ovary; the ripened ovary is the fruit.

or polycystic ovary syndrome (PCOS)

Endocrine disorder in women, characterized by high levels of male hormones (androgens) and infrequent or absent ovulation (see reproductive system). It causes a high proportion of female infertility cases. Symptoms vary but often include increased serum concentrations of androgens, insulin resistance, hirsutism, acne, and obesity. Menstruation may be irregular, absent, or excessive. The ovaries are usually enlarged and contain cysts. The disease may remain undiagnosed until a woman tries to conceive. The underlying cause is not fully understood, and no genetic mutations have been associated with the syndrome. Many women with Stein-Leventhal syndrome are at an increased risk of developing metabolic disorders such as type II diabetes or lipid disorders such as atherosclerosis at an unusually young age. Treatment attempts to reduce androgen production. Infertility may be treated with clomiphene citrate or gonadotropins to induce ovulation.

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In zoology, the female reproductive organ (see reproductive system) that produces eggs and sex hormones (estrogen and progesterone). Human females have two ovaries, almond-shaped organs about 1.5 in. (4 cm) long. They contain hollow balls of cells (follicles) that hold immature eggs. About 150,000–500,000 follicles usually are present at birth; by young adulthood, only about 34,000 remain. The number continues to decrease until menopause, when the few remaining follicles decay and the ovaries shrink and produce far less estrogen. Only 300–400 follicles mature and release an egg, which develops into an embryo if fertilized or, if not, passes from the body with menstruation. In botany, an ovary is the enlarged base of a flower's female organ (pistil). It contains ovules, which develop into seeds when fertilized, and matures into a fruit.

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"Ovaria" redirects here. This is also a proposed section and a synonym of Solanum.

An ovary is an ovum-producing reproductive organ found in female organisms. It is often found in pairs as part of the vertebrate female reproductive system. Ovaries in females are homologous to testes in males. The term gonads refers to the ovaries in females and testes in males.

Human anatomy

Ovaries are oval shaped and, in the human, measure approximately 3 cm x 1.5 cm x 1.5 cm. The ovary (for a given side) is located in the lateral wall of the pelvis in a region called the ovarian fossa. The fossa usually lies beneath the external iliac artery and in front of the ureter and the internal iliac artery.

Each ovary is then attached to the Fimbre of the Fallopian Tube. Usually each ovary takes turns releasing eggs every month; however, if there was a case where one ovary was absent or dysfunctional then the other ovary would continue providing eggs to be released.

Ligaments

In the human the paired ovaries lie within the pelvic cavity, on either side of the uterus, to which they are attached via a fibrous cord called the ovarian ligament. The ovaries are uncovered in the peritoneal cavity but are tethered to the body wall via the suspensory ligament of the ovary. The part of the broad ligament of the uterus that covers the ovary is known as the mesovarium.

Extremities

There are two extremities to the ovary:

• The end to which the uterine tube attach is called the tubal extremity.
• The other extremity is called the uterine extremity. It points downward, and it is attached to the uterus via the ovarian ligament.

Histology

• The outermost layer is called the germinal epithelium.
• The tunica albuginea covers the cortex.
• The ovarian cortex consists of ovarian follicles and stroma in between them. Included in the follicles are the cumulus oophorus, membrana granulosa (and the granulosa cells inside it), corona radiata, zona pellucida, and primary oocyte. The zona pellucida, theca of follicle, antrum and liquor folliculi are also contained in the follicle. Also in the cortex is the corpus luteum derived from the follicles.
• The innermost layer is the ovarian medulla. It can be hard to distinguish between the cortex and medulla, but follicles are usually not found in the medulla.

See also

• Ovarian disease

Additional images

References

External links

• From the American Medical Association
• Merck Online Medical Library: Female Reproductive System

See also

• Oophorectomy
• Menopause
• Ovum
• Corpus luteum
• Cervix
• Vagina