The menstrual cycle is controlled by female hormones, which are powerful chemicals made in the endocrine glands. Hormones travel in the bloodstream to various parts of the body, where they act as triggers for certain functions. A physician who specializes in hormones and diseases of the endocrine glands is an endocrinologist. The nervous and endocrine system interacts. The study of this interaction is neuroendocrinology.
The female hormone estrogens was discovered in the 1920s. Not all of its very complex functions are yet completely understood. The name comes from Greek and Latin. Estrus refers to the monthly period. Gen means born or generated. Menses is the actual flow. Menarche is a girl's first period.
An estrogen is a generic term for female hormones like estradiol, estrone and estriol. At puberty, estrogens feminize the body of a girl: breasts, wider hips, fat layer under the skin, and so on. Estrogens are produced mainly in the ovaries, with a huge surge on days 12 to 14 of the monthly cycle for the release of an egg at ovulation. There is another surge on days 22 to 24.
Estrogen is also produced in the adrenal glands, fat cells, and the placenta at pregnancy. Women (and men) with a high-fat diet tend to have more estrogen in the blood and less in the urine. Too much estrogen can bring pre-cancer changes in the breast, cervix, uterus, and ovaries; a very fat woman would do well to diet. Avery fat man who produces excess estrogen can develop gynecomastia (male breasts). Estrogen protects women from early heart disease. It raises the good kind of cholesterol, HDL, and lowers the bad kind, LDL. Avoid over-slimming; a certain amount of fats cells are necessary to support estrogen activity.
Progesterone works with estrogen to ripen the egg. It prepares the uterus lining for pregnancy. If the egg is not fertilized, progesterone output drops and the uterine lining sheds. This is menstruation. Progesterone is produced in the ovaries, with only one surge on days 22 to 24 of the monthly cycle.
Testosterone is the hormone of the libido. This is the medical term for the sex drive in both men and women. Women produce testosterone in the ovaries and the adrenal glands; men mainly produce it in the testicles and less in the adrenals. When the ovaries slow down at menopause, testosterone continues to be produced in the adrenals (and a little in the ovaries). This is why the female sex drive does not shut off at midlife.
Women are beautiful, homely, or plain. They are tall, medium, or short. Their sex drives are as individual as their looks or their height. Some female libidos are powerful, others are mild. In the strength of the sex drive, women are more like men than they are like one another. As far as the libido goes, the genders are much the same.
Male hormones are called androgens because they support and maintain the growth of male tissues, not because they are made by men. Estrogen supports and maintains the growth of the softer, plumper, moister, female-specific tissues. Men also make estrogen in their testicles. Obviously, they need greater amounts of the male hormones to sustain the masculine characteristics. The typical range of testosterone circulating in the blood (ng/dl) is:
Pubertal boys 120-600
Spots which appear prior to a period are due to the drop in female hormones which allows the male hormones to have a greater effect. Testosterone stimulates the sebaceous glands and is linked to acne in both genders. If acne is troublesome or persists, visit the physician. Various medications, including the antibiotic tetracycline, can clear acne. Women using the Pill find that their spots clear up.