which of the following disorders is characterized by the wasting away of muscles due to the progressive loss of myofibrils?
Muscle disorders are caused by disruption of normal innervation, degeneration and replacement of muscle cells, injury, lack of use or disease. Atrophy. Muscular atrophy refers to a decrease in size of muscles. Individual muscle fibers decrease in size, and there is a progressive loss of myofibrils. Disuse atrophy is a muscular atrophy that results from lack of muscle use. Bedridden people, people with limbs in casts, or those who are inactive for other reason experience disuse atrophy in the muscles that are not used.