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glossary:degeneration

Degeneration

(1) Deterioration; change from a higher to a lower form, especially change of tissue to a lower or less functionally active form. When there is chemical change of the tissue itself it is true degeneration; when the change consists in the deposit of abnormal matter in the tissues, it is infiltration.

(2) Med. deterioration in structure or function of cells, tissues, or organs, as in disease or aging

Types of Degeneration

Albuminoid degeneration

Cloudy swelling, an early stage of degenerative change characterized by swollen, parboiled-appearing tissues which revert to normal when the cause is removed.

Ascending degeneration

Wallerian degeneration affecting centripetal nerve fibers and progressing toward the brain or spinal cord.

Ballooning degeneration

Swelling of the cytoplasm in epidermal cells without vacuolization, enlarged or condensed nuclei and acantholysis. A characteristic of viral infections of the skin. Called also koilocytosis.

Calcareous degeneration

Degeneration of tissue with deposit of calcareous material.

Caseous degeneration

Caseation (2). necrosis in which tissue is changed into a dry mass resembling cheese.

Cerebromacular degeneration

(CMD), cerebroretinal degeneration 1. degeneration of brain cells and of the macula retinae. 2. any lipidosis with cerebral lesions and degeneration of the macula retinae. 3. any form of neuronal ceroid-lipofuscinosis.

Colloid degeneration

Degeneration with conversion of the tissues into a gelatinous or gumlike material.

Congenital macular degeneration

Hereditary macular degeneration with a cystlike lesion that in the early stages resembles egg yolk.

Crooke's hyaline degeneration

Crooke's hyalinization. Crooke's hyaline degeneration Crooke's hyalinization.

Cystic degeneration

Degeneration with formation of cysts.

Ddescending degeneration

Wallerian degeneration extending peripherally along nerve fibers.

Disciform macular degeneration

A form of macular degeneration seen in persons over age 40, in which sclerosis involving the macula and retina is produced by hemorrhages between Bruch's membrane and the pigment epithelium.

Fatty degeneration

Deposit of fat globules in a tissue.

Feathery degeneration

Said of hepatocytes; a hydropic change in hepatocytes which have suffered long-term exposure to cholestasis.

Fibrinoid degeneration

Deposition or replacement with eosinophilic fibrillar or granular substance resembling fibrin.

Fibroid degeneration

Degeneration into fibrous tissue.

Fibrinous degeneration

Necrosis with deposit of fibrin within the cells of the tissue.

Gray degeneration

Degeneration of the white substance of the spinal cord, in which it loses myelin and assumes a gray color.

Hepatolenticular degeneration

Wilson's disease. an inherited, progressive disorder of copper metabolism, with accumulation of copper in liver, brain, kidney, cornea, and other tissues; it is characterized by cirrhosis in the liver, degenerative changes in the brain, and a pigmented ring at the outer margin of the cornea.

Hyaline degeneration

A regressive change in cells in which the cytoplasm takes on a homogeneous, glassy appearance; also used loosely to describe the histological appearance of tissues. Called also hyalinosis.

Hhydropic degeneration

Calcareous degeneration degeneration of tissue with deposit of calcareous material.

Lattice degeneration

Of retina an often bilateral, usually benign asymptomatic condition, characterized by patches of fine gray or white intersecting lines in the peripheral retina, usually with numerous round punched-out areas of retinal thinning or retinal holes.

Macular degeneration

Degenerative changes in the macula retinae.

Mucoid degeneration

Degeneration with increased mucin which can be epithelial or mesenchymal in origin.

Mucous degeneration

Degeneration with accumulation of mucus in epithelial tissues. Called also myxomatous degeneration.

Myxomatous degeneration

Degeneration in which mucus accumulates in connective tissues. see mucous degeneration (above).

Reticular degeneration

Extreme intracellular edema of epidermal cells, resulting in rupture and multilocular intraepidermal vesicles with septae formed by the remaining cell walls. Seen in acute inflammatory dermatoses.

Spongy degeneration

On microscopic examination has the physical appearance of a sponge. Usually applied to tissue of the central nervous system, caused by the loss of myelin.

Spongy degeneration of central nervous system

A rare hereditary form of leukodystrophy of early onset in which widespread demyelination and vacuolation of cerebral white matter gives it a spongy appearance; there is mental retardation, megalocephaly, atony of neck muscles, limb spasticity, and blindness, with death in infancy.

Spongy degeneration

Of white a rare hereditary form of leukodystrophy of early onset in which widespread demyelination and vacuolation of cerebral white matter gives it a spongy appearance; there is mental retardation, megalocephaly, atony of neck muscles, limb spasticity, and blindness, with death in infancy.

Striatonigral degeneration

A form of multiple system atrophy with nerve cell degeneration mainly in the region of the substantia nigra and the neostriatum; symptoms are similar to those of parkinsonism.

Subacute combined degeneration

Of spinal cord degeneration of posterior and lateral columns of the spinal cord, with various motor and sensory disturbances; it is due to vitamin B12 deficiency and usually associated with pernicious anemia.

Tapetoretinal degeneration

Degeneration of the pigmented layer of the retina.

Transneuronal degeneration

Atrophy of certain neurons after interruption of afferent axons or death of other neurons to which they send their efferent output.

Zenker's degeneration

Hyaline degeneration and necrosis of striated muscle.

glossary/degeneration.txt · Last modified: 2012/10/16 14:40 (external edit)