Production of egg cells
The ovaries are the site of production and periodical release of egg cells, the female gametes. In the ovaries, the developing egg cell (or oocyte) grows within the environment provided by follicles (see folliculogenesis). Follicles are composed of different types and number of cells according to the stage of their maturation and their size is indicative of the stage of oocyte development.
When the oocyte finishes its maturation in the ovary (see oogenesis), a surge of luteinizing hormone secreted by the pituitary gland stimulates the release of the oocyte through the rupture of the follicle, a process called ovulation. 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.
Secretion of testosterone and progesterone
Ovaries secrete both estrogen and progesterone. Estrogen is responsible for the appearance of secondary sex characteristics of females at puberty and for the maturation and maintenance of the reproductive organs in their mature functional state. Progesterone functions with estrogen by promoting menstrual cycle changes in the endometrium.
The first appearance of the gonad is essentially the same in the two sexes, and consists in a thickening of the mesothelial layer of the peritoneum. The thick plate of epithelium extends deeply, pushing before it the mesoderm and forming a distinct projection. This is termed the gonadal ridge. The ovary is thus formed mainly from the genital ridge and partly from the mesonephros, during the further development.
The ovaries are the female gonads. Paired ovals, they are each about 2 to 3 cm in length, about the size of an almond (Pic.1). Each one is whitish in color and located alongside the lateral wall of the uterus 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.
The ovaries are not attached to the fallopian tubes but to the outer layer of the uterus via the ovarian ligaments (Pic. 2). Usually each ovary takes turn 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.
There are two extremities to the ovary:
The ovaries comprises an outer covering of cuboidal epithelium called the
Histologically, the ovary has two main sections:
The outermost layer of the ovary called the:
The innermost layer is the:
The mature follicles developed in ovarian cortex consist of (Pic. 3):
The absence of a menstrual period in women of reproductive age.
An eating disorder characterized by the maintenance of a body weight below average, fear of gaining weight, and a distorted body image.
Failure of the ovaries to release an oocyte over a period of time generally exceeding 3 months.
A state in which pieces of the tissue alike to the lining of the uterus (endometrium) grow in other parts of the body.
A hydrosalpinx is an abnormal pouch containing liquid in a fallopian tube.
The presence of abnormally high levels of prolactin in the blood.
A medical term which describes a diminished functional activity of the gonads – the testes and ovaries.
A surgery performed to remove a woman's uterus.
A genetic condition where the primary symptom is a failure to start puberty or a failure to fully complete puberty.
The luteinisation of ovulatory follicle without a release of an oocyte.
The time in most women's lives when menstrual periods stop permanently, and the woman is no longer able to have children.
An abnormal condition in a woman's menstrual cycle.
Light or infrequent menstrual ﬂow at intervals of 39 days to 6 months or 5–7 cycles in a year.
A type of cancer in which abnormal cells begin to grow in one or both of a woman's ovaries.
Surgical removal of one or both ovaries.
A form of abdominal adhesions in the pelvis.
Infection of the upper part of the female reproductive system and a common complication of some sexually transmitted diseases.
A condition in which a woman has an imbalance of female sex hormones. This may lead to changes in the menstrual cycle, cysts in the ovaries, trouble g
A condition of low fertility characterized by low numbers of remaining oocytes in the ovaries or possibly impaired oocyte development or recruitment.
The loss of function of the ovaries before age 40.
A distally blocked Fallopian tube filled with pus.
A medical condition impairing the function of the thyroid.
The type of blockage that affects the part of the fallopian tube end towards the ovary.
Turner syndrome is a genetic disorder in which a female is partly or completely missing one X chromosome that results in ovarian dysgenesis.
Congenital uterine malformation where both Müllerian ducts develop but fail to fuse, thus the woman has a "double uterus".
Two very fine tubes that transport sperm toward the egg, and allow passage of the fertilized egg back to the uterus for implantation.
An ovarian structure with two major functions, namely, the production of hormones and growth of oocytes capable of being fertilized.
A group of granulosa cells that support the oocyte in an antral follicle.
A female germ cell involved in reproduction.
A hormone, that provokes the regression of male fetal Müllerian ducts.
Steroid hormone, secreted by the ovaries, whose function is to prepare the uterus for the implantation of a fertilized ovum and to maintain pregnancy.
The absence of a menstrual period in a woman of reproductive age.
An anovulatory cycle is a menstrual cycle during which the ovaries do not release an oocyte.
A disease involving the heart and the blood vessels, such as coronary artery disease.
The loss of menstrual cycles for at least 6 consecutive months.
Lower levels of Anti-Müllerian hormone according to the age.
A condition of low serum levels of estrogen.
An organism has passed the usual age of onset of puberty with no physical or hormonal signs.
Abnormal levels of one of the gonadotropin hormones, LH and FSH.
Short or scanty periods with extremely light menstrual blood flow.
A condition with high serum follicle–stimulating hormone (FSH) concentration.
The failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse.
The medical term for infrequent, often light menstrual periods (intervals exceeding 35 days).
Irregular menstruation is a menstrual disorder whose manifestations include irregular cycle lengths as well as metrorrhagia
Decrease of facial and body hair in males.
The absence of sexual appetite.
The age at onset of first menstruation.
The medical term for cycles with intervals of 21 days or fewer.
A combination of physical and emotional disturbances that occur after a woman ovulates and ends with menstruation.
Retrograde flow of menstrual fluid through fallopian tubes into the pelvic cavity.
The biological development of sex differences, changes that make a male body different from a female body.