hyperplasiapathology
Main
Aspects of this topic are discussed in the following places at Britannica.
Assorted References
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abnormal cell growth ( in tumour
)
...more of the following alterations: (1) hypertrophy, or an increase in the size of individual cells; this feature is occasionally encountered in tumours but occurs commonly in other conditions; (2) hyperplasia, or an increase in the number of cells within a given zone; in some instances it may constitute the only criterion of tumour formation; (3) anaplasia, or a regression of the physical...
in human disease: Cell growth inhibition )...to reconstitute the tissue to its previous state of normal structure and function, following which tightly regulated growth resumes. Such areas of increased cell growth are referred to as hyperplasias; they consist of expanded numbers of normal-appearing cells and, depending on the duration of growth, can result in an enlargement of tissues and organs. In general, hyperplasias arise...
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endocrine glands ( in endocrine system, human: Endocrine hyperfunction
)
Endocrine glands that produce increased amounts of hormone are considered hyperfunctional and may undergo hypertrophy (increase in the size of each cell) and hyperplasia (increase in the number of cells). The hyperfunction may be primary, caused by some abnormality within the gland itself, or secondary (compensatory), caused by changes in the serum concentration of a substance that normally...
in human disease: Diseases of metabolic-endocrine origin )...(hyperfunction) or underproduction (hypofunction) of some hormone-secreting endocrine gland. There are relatively few causes of hormone overproduction. In general, overproduction results from hyperplasia, an increase in the number of cells (in this case, hormone-secreting cells) in a specific endocrine gland. It can also be caused by neoplasia, the growth of a tumour in an endocrine...
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fetal growth
( in childhood disease and disorder: Endocrine disorders )
Congenital adrenal hyperplasia is a group of conditions in which there is a defect in the production of normal adrenocortical-steroid hormones (secretions of the cortex, or outer substance, of the adrenal glands). Excessive stimulation of the cortex of the adrenals by a pituitary hormone (adrenocorticotropic hormone, or ACTH) results in abnormal enlargement of the glands and overproduction of...
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hormonal effect
( in hormone: Thyrotropin (thyroid-stimulating hormone; TSH) )
...through a feedback relationship similar to that for ACTH; thyrotropin increases the secretion of the hormones from the thyroid gland and, if its action is prolonged, evokes increase in cell number (hyperplasia) and increase in size of the gland. One consequence of an overactive thyroid in man is a bulging of the eyes (exophthalmos). The cause of this is obscure, although it has been thought to...
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tissue growth
( in materials science: Cardiovascular devices )
Occasionally, excessive tissue growth may be observed at the anastomosis, which is where the graft is sewn to the native artery. This is referred to as internal hyperplasia and is thought to result from differences in compliance between the graft and the host vessels. In addition, in order to optimize compatibility of the biomaterial with the blood, the synthetic graft eventually should be...
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abnormal cell growth ( in tumour
)
...more of the following alterations: (1) hypertrophy, or an increase in the size of individual cells; this feature is occasionally encountered in tumours but occurs commonly in other conditions; (2) hyperplasia, or an increase in the number of cells within a given zone; in some instances it may constitute the only criterion of tumour formation; (3) anaplasia, or a regression of the physical...
in human disease: Cell growth inhibition )...to reconstitute the tissue to its previous state of normal structure and function, following which tightly regulated growth resumes. Such areas of increased cell growth are referred to as hyperplasias; they consist of expanded numbers of normal-appearing cells and, depending on the duration of growth, can result in an enlargement of tissues and organs. In general, hyperplasias arise...
-
endocrine glands ( in endocrine system, human: Endocrine hyperfunction
)
Endocrine glands that produce increased amounts of hormone are considered hyperfunctional and may undergo hypertrophy (increase in the size of each cell) and hyperplasia (increase in the number of cells). The hyperfunction may be primary, caused by some abnormality within the gland itself, or secondary (compensatory), caused by changes in the serum concentration of a substance that normally...
in human disease: Diseases of metabolic-endocrine origin )...(hyperfunction) or underproduction (hypofunction) of some hormone-secreting endocrine gland. There are relatively few causes of hormone overproduction. In general, overproduction results from hyperplasia, an increase in the number of cells (in this case, hormone-secreting cells) in a specific endocrine gland. It can also be caused by neoplasia, the growth of a tumour in an endocrine...
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fetal growth childhood disease and disorder
Congenital adrenal hyperplasia is a group of conditions in...
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reproductive system disease reproductive system disease
Benign prostatic hyperplasia, an overgrowth of normal glandular and muscular elements of the prostate gland, arises in the immediate vicinity of the urethra and is the most frequent cause of urinary obstruction. The enlarged prostate usually causes symptoms after the age of 40. If undetected, the obstruction may cause bladder and kidney damage. The diagnosis is made by rectal examination or...
Student Encyclopædia Britannica articles specifically written for elementary and high school students.
- How Stuff Works - Health - Herbal Remedies for Benign Prostatic Hyperplasia
- How Stuff Works - Healthguide - Benign Prostatic Hyperplasia In-Depth
enlargement of the adrenal glands resulting primarily from excessive secretion of androgenic hormones by the adrenal cortex. Congenital adrenal hyperplasia mainly affects infants and is caused by mutations in the genes for enzymes that catalyze the production of cortisol by the adrenal glands. As a result of decreased cortisol production, there is increased secretion of the anterior pituitary hormone corticotropin. The high levels of corticotropin may restore cortisol secretion to near normal; however, they also stimulate the production of androgen and sometimes mineralocorticoids (hormones that stimulate retention of salt and water by the kidneys) by the adrenal cortex.
The most common type of congenital adrenal hyperplasia is deficiency of 21-hydroxylase, an enzyme that stimulates one of the last steps in cortisol synthesis. Excess androgen produced to overcome this deficiency during fetal life results in virilization—the development of masculine-appearing external genitalia in newborn girls and precocious sexual development in boys—that becomes prominent as the child grows. There may also be decreased production of aldosterone, which leads to increased urinary excretion of sodium and water and decreased urinary excretion of potassium, resulting in low blood pressure, low serum sodium concentrations (hyponatremia), and high serum potassium concentrations (hyperkalemia). Other, rarer forms of congenital adrenal hyperplasia result in varying degrees of hypertension or lack of sexual development, depending on the particular enzyme that is defective.
Congenital adrenal hyperplasia also occurs in adolescents and adults, in which case it is referred to as late-onset congenital adrenal hyperplasia. In...
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congenital adrenal hyperplasia congenital adrenal hyperplasia
Patients of any age with congenital hyperplasia are treated with cortisol or a synthetic hormone with similar properties, such as prednisone; some patients may also require mineralocorticoid treatment.
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dermatomyositis dermatomyositis
Corticosteroids, such as prednisone, are the most common treatment for dermatomyositis. Immunoglobulins and immunosuppressive drugs such as methotrexate also are used.
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effect on adrenal gland adrenal gland
Adrenocortical hyperfunction may be congenital or acquired. Congenital hyperfunction is always due to hyperplasia (enlargement) of both adrenal glands, whereas acquired hyperfunction may be due to either an adrenal tumour or hyperplasia. Congenital adrenal hyperplasia, also known as the adrenogenital syndrome, is a disorder in which there is an...
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