gigantism(redirected from pituitary gigantism)
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gigantism,condition in which an animal or plant is far greater than normal in size. Plants are often deliberately bred to increase their size. However, among animals, gigantism is usually the result of hereditary and glandular disturbance. Among humans, gigantism is produced by an oversecretion of growth hormones by the acidophilic cells in the anterior lobe of the pituitary, causing excessive growth of all the tissues of the body. The metabolic rate is usually at least 20% above normal, which could be caused by an excess of the growth hormone alone, or oversecretion of the thyroid hormone in addition. Usually hyperglycemia (overactivity of the insulin-producing cells of the pancreas) is present. This condition eventually leads to degeneration of the islet cells, causing diabetes. Because of these metabolic abnormalities, the life expectancy of a giant is considerably less than normal. The treatment for gigantism is usually irradiation of the pituitary. The excessive height of the pituitary giant, which is defined at various levels above 7 ft (213 cm), is caused by excessive growth of the long bones. However, if the pituitary becomes overactive after growth is complete (marked by closure of the epiphyses of the long bones), the condition known as acromegalyacromegaly
, adult endocrine disorder resulting from hypersecretion of growth hormone produced by the pituitary gland. Since the bones cannot increase in length after full growth is attained, there is a disproportionate thickening of bones, predominantly in the skull and small
..... Click the link for more information. results. Giantsgiant,
in mythology, manlike being of great size and strength. The giant has been the symbol for the expression of certain recurring beliefs in the mythologies of all races.
..... Click the link for more information. appear in the legends and folklore of many cultures.
excessive growth in humans. A height exceeding 190 cm may acquire a pathological character. Giants over 200 cm tall are rarely encountered; the tallest human described in the literature was 320 cm tall. Gigantism is observed more often in males, is usually manifested at nine-ten years of age or during the period of sexual maturation, and continues during the physiological growth of the body. The causes of gigantism are not known; it is presumed that it is connected with intensified function of the anterior pituitary gland, which produces the growth hormone. Giants of pathological height experience poor health and rarely live to old age. They are often psychologically infantile, and their sex drive is absent or decreased. Externally, there is elongation of the extremities, especially the lower ones; the head appears unusually small. There exists partial gigantism, which is characterized by the enlargement of part (for example, the feet) or half of the body. Treatment includes X-ray and hormone therapy, sometimes surgery.