Sophronia L. Gallop
As the blood flows through these glands, it picks up the hormones and carries them around the body. The hormones are needed to control the many complex chemical processes that go on inside your body. The chemistry of life would be impossible without them. If anything goes wrong with one of these glands, so that it produces too much or too little of one hormone or another, the body chemistry is upset and some diseases result.
One such disease is diabetes. The disease itself was known in ancient times. Its symptoms were described by Egyptian, Greek, and Roman doctors. But they did not have the slightest idea of what caused it. All they knew was that the victims of the disease began to waste away. They grew thinner and thinner and suffered constantly from a terrible thirst. Death ended their suffering.
The first important discovery about diabetes was made in the seventeenth century by an English doctor named Thomas Willis. He found that there was sugar in the urine of patients suffering from diabetes. A century later, another English doctor, Matthew Dobson, showed that in diabetes there was more sugar in the blood than is normal. But no one understood why these things were so.
Another century went by before a start was made toward clearing up the mystery. Strangely enough, this was done by doctors who had no thought of studying diabetes.
Toward the end of the nineteenth century, a German professor, Friedrich Naunyn, suggested that two of his assistants, Oscar Minkowski and Joseph von Mering, try to find out if the pancreas is necessary for life. The pancreas is a soft organ of pinkish-yellow color, about ten inches long, Iying beside the stomach. It manufactures a digestive juice called the pancreatic juice, which flows into the small intestine. Minkowski and Von Mering operated on some dogs, removing their pancreas.
The mystery of diabetes was finally solved in our own century. The work of a number of medical scientists disclosed that the pancreas serves two purposes. It not only manufactures a digestive juice but also produces a hormone called insulin. It is produced by clusters of cells in the pancreas called the Islets of Langerhans.
The blood, as it flows through the pancreas, picks up insulin.
Klinefelter’s Syndrome
Individuals with the Klinefelter syndrome typically have a 47,XXY karyotype and a predominantly male phenotype. Before puberty, patients have small testes with decreased numbers of spermatogonia, but otherwise they have a normal male phenotype. Most persons with the disorder come to the attention of physicians after the time of expected puberty because of infertility, breast enlargement (gynecolomastia), or incomplete virilization. Typical histologic changes in the testes include hyalinization of the spermatogenic tubules, absence of spermatogenesis, and normal Leydig cells. Bilateral, painless, gynecomastia usually appears during adolescence and may eventually become disfiguring. Most patients have a male psychosexual orientation and function physically and socially as men.
Endocrine findings include low to normal plasma testosterone and elevated levels of circulation estradiol. The precise source of the elevated plasma estradiol is not known but may be due to an increased testicular secretion, a decreased metabolic clearance rate, or an increased rate of testosterone conversion to estradiol in peripheral tissues. The net result of this imbalance in the androgen to estrogen ratio is varying degrees of insufficient virilization and enhanced feminization.
Circulating gonadotropins (especially follicle-stimulating hormone) are elevated as a consequence of the damage to the seminiferous tubule resulting in decreased feedback on the hypothalamic—pituitary system. Progressive sclerosis of the seminiferous tubules eventually leads to diminished testicular blood flow, diminished testosterone secretion, and enhanced levels of luteinizing hormone.
Gonadal Dysgenesis (Turner’s Syndrome)
Gonadal dysgenesis a disorder in phenotypic females characterized by primary amenorrhea, lack of secondary sexual characteristics, short stature, multiple congenital anomalies, and bilateral streak gonads. The common chromosomal karyotype associated with this disorder is 45,X. Other affected individuals have mosaicism of this chromosomal complement with a 46,XX-containing cell line or structural abnormalities of one of the X chromosomes. The diagnosis is usually made in infancy or at the onset of puberty, when amenorrhea and failure of feminization are noted in conjunction with the other somatic abnormalities. The external genitalia are unambiguously female but remain immature. There is no spontaneous breast development
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The internal genitalia consist of small but otherwise normal Fallopian tubes and uterus. Although primordial germ cells migrate to the gonads and are present transiently in embryogenesis, they disappear before birth. After the age of puberty the gonads are identifiable only as fibrous streaks in the broad ligament. Although individuals with gonadal dysgenesis differentiate as phenotypic females, the secondary sex characteristics do not develop properly due to lack of female sex hormones. Thus, it is apparent that normal ovarian development requires the presence of two functionally intact X chromosomes.
Disorders of Gonadal Sex
Disorders of gonadal sex occur when chromosomal sex is normal, but for one reason or another differentiation of the gonads is abnormal. Thus, depending on the time during embryogenesis when the gonadal defect is manifest, the chromosomal sex may or may not correspond to the phenotypic sex of the individual.
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