Medical term about Atrophy 

Atrophy is a medical term that refers to a decrease in size of an organ or part of the body. Atrophy may result from disuse; for example, long-term immobility of a leg due to paralysis may lead to atrophy of the leg muscles. Atrophy may also result from cell death, loss of blood supply, malnutrition, or hormonal changes.

For example: Alzheimer's disease causes progressive atrophy to the brain as brain cells (neurons) die during the course of the disease.

by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain