Wasting away or shrinkage of a normally developed tissue or organ due to a reduction in the size or number of its cells. Atrophy is commonly caused by disuse or inadequate cell nutrition due to poor blood circulation. It may also occur during prolonged illness, when the body needs to use up the protein reserves in muscles.
In some circumstances, atrophy is a normal process, as in ovarian atrophy in women who have passed the menopause.
Atrophy occurs when normal tissue, an organ or even the whole body wastes because the constituent cells die. Undernourishment, disease, injury, lack of use or AGEING may cause atrophy. Muscular atrophy occurs in certain neurological diseases such as POLIOMYELITIS or MUSCULAR DYSTROPHY. The ovary (see OVARIES) atrophies at the MENOPAUSE. (See also MUSCLES, DISORDERS OF.)
Wasting of a tissue or organ
n. the wasting away of a normally developed organ or tissue due to degeneration of cells. This may be physiological or pathological. Physiological atrophy occurs during embryonic life and the neonatal period (web spaces, notochord, umbilical vessels), in adolescence (the thymus), in adult life (the *corpus luteum during the menstrual cycle), and in a variety of organs and tissues in old age. Pathological atrophy may occur through starvation, disuse, denervation, abnormal hormonal stimulation, lack of hormonal stimulation, or ischaemia. Muscular atrophy is associated with various diseases, such as poliomyelitis.
a rare hereditary disorder, usually affecting young males, that is characterized by loss of central vision due to neuroretinal degeneration. Visual loss in one eye is rapid and usually followed by loss in the second eye. [T. Leber]... leber’s optic atrophy
(MSA) a condition that results from degeneration of cells in the *basal ganglia (resulting in *parkinsonism), the *cerebellum (resulting in *ataxia), the *pyramidal system, and the *autonomic nervous system (resulting in symptoms of autonomic failure, such as postural hypotension).... multiple system atrophy
(SMA) a hereditary condition in which cells of the spinal cord die and the muscles in the arms and legs become progressively weaker. Eventually the respiratory muscles are affected and death usually results from respiratory infection. Most affected individuals are wheelchair-bound by the age of 20 and few survive beyond the age of 30. The gene responsible has been located: in affected children it is inherited as a double *recessive. There are three forms of the disease, based on severity of the symptoms and the age at which they appear. Type 1 (infantile spinal muscular atrophy) is the most acute and aggressive form of the condition (see Werdnig–Hoffmann disease). Type 2 develops between the ages of 6 months and 2 years and type 3 (Kugelberg–Welander disease), the least severe form, appears between 2 and 17 years of age.... spinal muscular atrophy