Hormones, in general, are chemical substances released by the glands that transmit messages to the different cells in the body. Thus, hormones can greatly affect each of the body's cells. Estrogen is widely known as the main female sex hormone. Although it exists in men, its function in the male anatomy is not yet known. Estrogen has three different compounds- estradiol, estriol and estrone. Each compound is produced during different stages in the female reproductive cycle. Estrogen is what makes women have wider hips, fuller breasts and generally a smaller body type than men.
Estrogen is a steroid hormone. Estrogen is naturally synthesized in the gonads and adrenal glands from cholesterol. Since estrogen is from cholesterol, this hormone is a lipid. One of the properties of a lipid is that it can permeate to cell walls and cling to hormone receptors, thus resulting to changes in the cells. In the cytoplasm of the cell, different changes may occur through enzyme action. That is why, when changes occur in the woman’s body, they are often attributed to hormones.
Estrogen is produced in the follicles in the ovaries, the placenta and the corpus luteum. When a woman is in the reproductive age, the ovary is the main site where estrogen is synthesized. Luteinizing hormone that is produced in the pituitary gland stimulates the estrogen production in the ovary. The enzyme aromatase transforms the androstenedione to estrone and testosterone to estradiol. Androstenedione is a steroid hormone that is produced in the adrenal glands and the gonads. An increase in the luteinizing hormone results in ovulation. Ovulation occurs when a follicle in the ovary ruptures and releases an ovum. The release of the ovum results in the production of a residual matter called corpus luteum where estradiol can also be synthesized. Estriol is produced in the placenta during pregnancy.
Estrogen plays an important role in women. During puberty, estrogen is responsible for the development of the breasts and the maturity of the female reproductive system. Hormones regulate the menstrual cycle. Estrogen circulates in the blood vessels and attaches itself to estrogen receptors in cells. Thus, estrogen not only affects the reproductive organs, but the other organs as well. Estrogen regulates metabolism in brain. The estrogen produced by the ovaries prevents bone loss.