Atrophy is the loss of volume or size of a part of an organism. It may affect
a muscle, an organ, a limb or a tissue. Atrophy may be caused by a pathology
or an associated disorder such as under nutrition, hormonal dysfunction, insufficient vascularization or an illness. It may also be provoked by an absence of cellular tissue renewal. When a part of an organism is not used, it eventually atrophies.