ESTROGEN A WONDERFUL HORMONE
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Date
2017
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جامعة الشيخ عبدالله البدري
Abstract
Estrogens are hormones that are important for sexual and reproductive development, mainly in
women. They are also referred to as female sex hormones. The term "estrogen" refers to all of
the chemically similar hormones in this group, which are estrone, estradiol (primary in women of
reproductive age) and estriol.
In women, estrogen is produced mainly in the ovaries. Ovaries are grape-sized glands located by
the uterus and are part of the endocrine system.
Estrogen is also produced by fat cells and the adrenal gland. At the onset of puberty, estrogen
plays a role in the development of so-called female secondary sex characteristics, such as breasts,
wider hips, pubic hair and armpit hair.
Estrogen also helps regulate the menstrual cycle, controlling the growth of the uterine lining
during the first part of the cycle. If the woman's egg is not fertilized, estrogen levels decrease
sharply and menstruation begins. If the egg is fertilized, estrogen works with progesterone,
another hormone, to stop ovulation during pregnancy.
During pregnancy, the placenta produces estrogen, specifically the hormone estriol. Estrogen
controls lactation and other changes in the breasts, including at adolescence and during
pregnancy.
Estrogen is instrumental in bone formation, working with vitamin D, calcium and other
hormones to effectively break down and rebuild bones according to the body's natural processes.
As estrogen levels start to decline in middle age, the process of rebuilding bones slows, with
postmenopausal women eventually breaking down more bone than they produce. This is why
postmenopausal women are four times more likely to suffer from osteoporosis than men,
according to the Cleveland Clinic.