- Wasting away or diminution. Muscle atrophy is wasting of muscle, decrease in muscle mass. A nerve can also show atrophy. For example, atrophy of the optic nerve diminishes vision.
* * *A wasting of tissues, organs, or the entire body, as from death and reabsorption of cells, diminished cellular proliferation, decreased cellular volume, pressure, ischemia, malnutrition, lessened function, or hormonal changes. SYN: atrophia. [G. atrophia, fr. a- priv. + trophe, nourishment]- alveolar a. diminution in size of the supportive tissues of the teeth due to lack of function, reduced blood supply, or unknown causes.- blue a. depressed blue atrophic scars due to injections in the skin of impure substances, as seen in narcotics addicts.- brown a. a. of the heart wall, especially in the elderly, in which the muscle is dark reddish brown and reduced in volume; the muscle fibers become pigmented especially about the nuclei, by lipochrome granules.- cerebellar a. a degeneration of the cerebellum, particularly the Purkinje cells, as the result of abiotrophy or of toxic agents, as in alcoholism.- choroidal vascular a. a. affecting either all choroidal vessels or only the choriocapillaris, occurring either diffusely or confined to the posterior pole of the eye.- congenital cerebellar a. familial disorder that causes degeneration of various cells in the cerebellum. Two types are recognized, one in which the granular layer cells degenerate, the other in which the Purkinje cells degenerate.- cyanotic a. a. due to destruction of the parenchymatous cells of an organ as a consequence of chronic venous congestion. SYN: red a..- cyanotic a. of the liver a sequela of longstanding hepatic congestion due to high pressure in the right atrium as in chronic constrictive pericarditis and severe, protracted right ventricular failure.- dominant optic a. an autosomal dominant bilateral optic neuropathy characterized by insidious preschool vision loss. SYN: Kjer optic a..- essential progressive a. of iris progressive a. of the iris without inflammatory signs, characterized by patchy loss of all layers of the iris with hole formation, migration of the pupil, degeneration of the corneal endothelium, peripheral anterior synechiae, and secondary glaucoma; usually unilateral, predominantly affecting women in their middle years. SEE ALSO: iridocorneal syndrome.- facioscapulohumeral a. SYN: facioscapulohumeral muscular dystrophy.- geographic retinal a. a pattern of well-demarcated retinal pigment epithelial a. associated with choriocapillary layer and photoreceptor a. leading to vision loss.- gyrate a. of choroid and retina [MIM*258870] a slowly progressive a. of the choriocapillaris, pigmentary epithelium, and sensory retina, with irregular confluent atrophic areas and an associated ornithinuria; autosomal recessive inheritance; due to a deficiency of ornithine δ-aminotransferase, caused by mutation in the ornithine δ-aminotransferase gene (OAT) on chromosome 10q.- horizontal a. a progressive loss of alveolar and supporting bone surrounding the teeth, beginning at the most coronal level of the bone. SYN: horizontal resorption.- Kjer optic a. SYN: dominant optic a..- Leber hereditary optic a. [MIM*535000] degeneration of the optic nerve and papillomacular bundle with resulting loss of central vision and blindness, progressive for several weeks, then usually becoming stationary with permanent central scotoma; the age of onset is variable, most often in the third decade; more males than females are affected. Mitochondrial or cytoplasmic inheritance via the maternal lineage, caused by mutation in the mitochondrial gene(s) acting autonomously or in association with each other.- multiple system a. nonhereditary, neurodegenerative disease of unknown cause, characterized clinically by the development of parkinsonism, ataxia, autonomic failure, or pyramidal track signs, in various combinations. Pathologically there are nerve cell loss, gliosis, and the accumulation of abnormal tubular structures in the cytoplasm and nucleus of oligodendrocytes and neurons in the basal ganglion, cerebellum, and intermediolateral columns of the spinal cord; can present as predominantly parkinsonism, as predominantly ataxia, or as a combination of parkinsonism, ataxia, and autonomic failure; it is a relatively rapidly progressive and fatal disorder.- neurotrophic a. abnormalities of the skin, hair, nails, subcutaneous tissues, and bone, caused by peripheral nerve lesions. SYN: neurogenic a., trophoneurotic a..- nutritional type cerebellar a. a restricted type of cerebellar cortical degeneration, affecting particularly the Purkinje cells of the anterior and superior vermis; probably caused by thiamin deficiency; most frequently seen in chronic alcoholics and then called alcoholic cerebellar degeneration.- olivopontocerebellar a. a group of genetically distinct, mostly autosomal dominant progressive neurologic diseases characterized by loss of neurons in the cerebellar cortex, basis pontis, and inferior olivary nuclei; results in ataxia, tremor, involuntary movement, and dysarthria; five clinical types (four with dominant, one with recessive inheritance) have been described, each type characterized by additional findings, such as sensory loss, retinal degeneration, ophthalmoplegia, and extrapyramidal signs. Several loci are involved, autosomal dominant [MIM*164400 to *164600] and recessive [MIM*258300]. SEE ALSO: spinocerebellar ataxia. SYN: olivopontocerebellar degeneration.- periodontal a. decrease in size and/or cellular elements of the periodontium after it has reached normal maturity.- peroneal muscular a. a group of peripheral neuromuscular disorders, sharing the common feature of marked wasting of the distal parts of the extremities, particularly the peroneal muscle groups, resulting in long, thin legs; it usually involves the legs before the arms with pes cavus often the first sign. There are two forms of hereditary sensorimotor polyneuropathies, i.e., a demyelinating type and an axonal loss type. Autosomal dominant [MIM*118200 and MIM*118220], autosomal recessive [MIM*214400], and X-linked recessive [MIM*302800, MIM*302801 and MIM*302802] forms exist. SYN: Charcot-Marie-Tooth disease.- Pick a. circumscribed a. of the cerebral cortex. SYN: lobar sclerosis, progressive circumscribed cerebral a..- pressure a. the wasting of hard or soft tissue resulting from excessive pressure applied to tissue by a denture base.- progressive spinal muscular a. one of the subgroups of motor neuron disease; a progressive degenerative disorder of the motor neurons of the spinal cord, manifested as progressive, often symmetrical, weakness and wasting, typically beginning in the distal portions of the limbs, particularly in the upper extremities, and spreading proximally; fasciculation potentials are often present, but evidence of corticospinal tract disease ( e.g., increased deep tendon reflexes, Babinski sign) is not.- pulp a. diminution in size and/or cellular elements of the dental pulp due to interference with the blood supply.- red a. SYN: cyanotic a..- senile a. wasting of tissues and organs with advancing age from decreased catabolic or anabolic processes, at times due to endocrine changes, decreased use, or ischemia. SYN: geromarasmus.- spinal muscular a. (SMA) a heterogeneous group of degenerative diseases of the anterior horn cells in the spinal cord and motor nuclei of the brainstem; all are characterized by weakness. Upper motor neurons remain normal. These diseases include Werdnig-Hoffmann disease (SMA type 1), SMA type 2, and Kugelberg-Welander disease (SMA type 3). SEE ALSO: Fazio-Londe disease.- spinal muscular a., type I [MIM*253300] the early infantile form, characterized by profound muscle weakness and wasting with onset at or shortly after birth; death occurs usually before 2 years of age. Autosomal recessive inheritance, caused by mutation in the survival motor neuron gene (SMN1) on 5q. About one-half of patients are also missing both homologs of a neighboring gene that encodes neuronal apoptosis inhibitory protein (NAIP), the loss of which is thought to influence the severity of the disease. SYN: familial spinal muscular a., Hoffmann muscular a., infantile muscular a., infantile progressive spinal muscular a., progressive infantile spinal muscular a., Werdnig-Hoffmann disease, Werdnig-Hoffmann muscular a..- spinal muscular a., type II [MIM*253550] a form intermediate in severity between the infantile form (SMA type I) and the juvenile form (SMA type III); characterized by proximal muscle weakness with onset usually between 3 and 15 months and survival until adolescence; autosomal recessive inheritance, caused by mutation in the SMN1 gene on 5q.- spinal muscular a., type III [MIM*253400] the juvenile form with onset in childhood or adolescence, characterized by progressive proximal muscular weakness and wasting, primarily in the legs, followed by distal muscle involvement, caused by degeneration of motor neurons in the anterior horns of the spinal cord; autosomal recessive inheritance, caused by mutation in the SMN1 gene on 5q. SYN: juvenile muscular a., juvenile spinal muscular a., Kugelberg-Welander disease, Wohlfart-Kugelberg-Welander disease.- Sudeck a. a. of bones, commonly of the carpal or tarsal bones, following a slight injury such as a sprain. SEE ALSO: causalgia, reflex sympathetic dystrophy. SYN: acute reflex bone a., posttraumatic osteoporosis, Sudeck syndrome.- transneuronal a. SYN: transsynaptic degeneration.- villous a. abnormality of the small intestinal mucosa with crypt hyperplasia, resulting in flattening of the mucosa and the appearance of a. of villi; clinically seen in malabsorption syndromes such as sprue.- Zimmerlin a. a variety of hereditary progressive muscular a. in which the a. begins in the upper half of the body.
* * *at·ro·phy 'a-trə-fē n, pl -phies decrease in size or wasting away of a body part or tissue also arrested development or loss of a part or organ incidental to the normal development or life of an animal or plantatrophy 'a-trə-fē, -.fī vb, -phied; -phy·ing vi to undergo atrophy <the inactive muscles atrophied> vt to cause to undergo atrophy <disuse atrophied the arm>
* * *n.the wasting away of a normally developed organ or tissue due to degeneration of cells. This may occur through undernourishment, disuse, or ageing. Forms of atrophy peculiar to women include the shrinking of the ovary at the menopause and of the corpus luteum during the menstrual cycle. Muscular atrophy is associated with various diseases, such as poliomyelitis.
* * *at·ro·phy (atґrə-fe) [Gr. atrophia] 1. a wasting away; a diminution in the size of a cell, tissue, organ, or part. See also atrophia and atrophie. 2. to undergo this process. atrophic adj
Medical dictionary. 2011.