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The Menstrual Cycle, TestingHistory

Gynecology, from the Greek meaning "the study of women," is a medical specialty dealing with the health of a woman's genital tract. The genital tract is made up of the reproductive organs including the vagina, cervix, uterus, ovaries, fallopian tubes, and their supporting structures.

Marked changes occur in a woman's reproductive organs upon her reaching menarche (the age at which she begins to menstruate) and again during any pregnancy that occurs in her life. Later, at the stage known as menopause, she experiences still other changes. It is the specialty of the gynecologist to guide women through these alterations and to ensure that they retain their health throughout each stage.

Maturity of the reproductive organs has to do with hormonal regulation of the organs centering on the pituitary gland in the brain. This gland, the master endocrine gland, stimulates the ovaries to produce other hormones that encourage the maturity of an ovum (egg). The egg is released from the ovary, is carried down to the uterus (womb), and if the egg is not fertilized the woman has her "period" or menses. This is the sloughing off of the lining of the uterus which is rebuilt each month in preparation to accept a fertilized ovum.

This cycle occurs approximately once a month or so if the woman is not pregnant. Thus, each month the uterus and the ovaries go through a cycle of preparation and dissolution and rebuilding far more profound than do any organs in the male body.

Until the late nineteenth century, physicians linked the female menstrual cycle to the phases of the moon. Of course, if that were so, every female would have her menstrual period at the same time. It was late in the nineteenth century that researchers attributed menstrual changes to hormones. Not until the early twentieth century were those hormones isolated in pure form and named. Female hormones as a group are called estrogens.

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