..... Click the link for more information. synthesized by the reproductive organs and adrenal glands adrenal gland (ədrēn`əl) or suprarenal gland
..... Click the link for more information. in females and, in lesser quantities, in males. The estrogens cause the thickening of the lining of the uterus uterus, in most female mammals, hollow muscular organ in which the fetus develops and from which it is delivered at the end of pregnancy . The human uterus is pear-shaped and about 3 in. (7.
..... Click the link for more information. and vagina in the early phase of the ovulatory, or menstrual, cycle (see menstruation menstruation, periodic flow of blood and cells from the lining of the uterus in humans and most other primates, occurring about every 28 days in women. Menstruation commences at puberty (usually between age 10 and 17).
..... Click the link for more information. ); in lower animals cyclical estrogen secretion also induces estrus, or "heat." The estrogens are also responsible for female secondary sex characteristics such as, in humans, pubic hair and breasts, and they affect other tissues including the genital organs, skin, hair, blood vessels, bone, and pelvic muscles.
The major estrogen secreted by the ovary is 17β-estradiol; this is converted to estrone in the blood. Estriol is the principal estrogen formed by the placenta during pregnancy. These three compounds, 17β-estradiol, estrone, and estriol, account for most of the estrogenic activity in humans.
The ability of estrogens to suppress secretion of follicle-stimulating hormone (FSH) by the pituitary gland pituitary gland, small oval endocrine gland that lies at the base of the brain . It is sometimes called the master gland of the body because all the other endocrine glands depend on its secretions for stimulation (see endocrine system ).
..... Click the link for more information. and thereby inhibit ovulation makes estrogen and estrogenlike compounds major components in oral contraceptives. Estrogen replacement therapy (ERT) uses synthetic estrogen (e.g., Premarin), typically given with progestins (e.g., Provera) to treat the physical changes of menopause menopause (mĕn`əpôz) or climacteric
..... Click the link for more information. , including hot flashes and vaginal dryness. ERT also retards the development of osteoporosis osteoporosis (ŏs'tēō'pərō`sĭs)
..... Click the link for more information. in postmenopausal women but increases the risk of breast cancer breast cancer, cancer that originates in the breast. Breast cancer is the second leading cause of cancer death in women (following lung cancer ). Even allowing for improvements in detection (i.e.
..... Click the link for more information. , heart attack (see infarction myocardial infarction or heart attack is usually caused by a blockage in one of the coronary arteries that supply blood to the heart muscle. The blockage typically occurs when a blood clot (see thrombosis ) lodges in an area already narrowed by arteriosclerosis ; other
..... Click the link for more information. ), stroke stroke, destruction of brain tissue as a result of intracerebral hemorrhage or infarction caused by thrombosis (clotting) or embolus (obstruction in a blood vessel caused by clotted blood or other foreign matter circulating in the bloodstream); formerly called
..... Click the link for more information. , and, when not given with progestins, uterine cancer. Estrogens are also used to treat prostate cancer.
estrogen
Any of a class of hormones that primarily influence the female reproductive system's development, maturation, and function. The three major estrogens—estradiol, estrone, and estriol—are produced mainly by the ovaries and placenta; the adrenal glands and the testes secrete smaller amounts. Estrogens affect the ovaries, vagina, fallopian tubes, uterus, and mammary glands and play crucial roles in puberty, menstruation, pregnancy, and parturition (labour). They also influence the structural differences between female and male bodies. In experimental animals, loss of estrogens diminishes mating desires and other behavioral patterns.
oestrogen (US), estrogen
Estrogen
A substance that maintains the secondary sex characters and organs, such as mammary glands, uterus, vagina, and fallopian tubes, of mammalian females. Naturally occurring substances with this activity are steroid hormones. The principal estrogenic hormone substances are 17(ß)-estradiol (with the structure shown), estrone, and estriol. They are produced and secreted directly into the bloodstream by the ovary, testis, adrenal, and placenta of pregnancy. Two other naturally occurring estrogenic hormones, equilin and equilenin, have been obtained only from the urine of pregnant mares and are apparently peculiar to that species. Stilbestrol, a synthetic compound with considerable estrogenic activity, has been used extensively in medical practice. See Hormone, Steroid
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