Atrophy

Atrophy
Mouse (right) with spinal muscular atrophy
Specialty	Pathology
Symptoms	Loss of body cells, signs of ageing
Types	Muscular atrophy, gland atrophy
Causes	Poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to target organ(s), excessive apoptosis of cells, insufficient exercise, ageing
Risk factors	Old age, sedentary lifestyle
Prognosis	Depends on the cause

Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, excessive amount of apoptosis of cells, and disuse or lack of exercise or disease intrinsic to the tissue itself. In medical practice, hormonal and nerve inputs that maintain an organ or body part are said to have trophic effects. A diminished muscular trophic condition is designated as atrophy. Atrophy is reduction in size of cell, organ or tissue, after attaining its normal mature growth. In contrast, hypoplasia is the reduction in the cellular numbers of an organ, or tissue that has not attained normal maturity.

Atrophy is the general physiological process of reabsorption and breakdown of tissues, involving apoptosis. When it occurs as a result of disease or loss of trophic support because of other diseases, it is termed pathological atrophy, although it can be a part of normal body development and homeostasis as well.