Final answer:
Muscle atrophy is the reduction of muscle size due to disuse or diseases such as cancer and AIDS. It is commonly seen as sarcopenia during aging and can dramatically affect the quality of life, but it can be mitigated to some extent through regular exercise. Inactivity, especially during extended periods, causes significant muscle weakening and loss.
Step-by-step explanation:
Muscle atrophy refers to the decrease in muscle size, which can occur due to various causes. This condition is associated with the wasting away of muscle tissue due to disuse or certain diseases. Conditions that can cause skeletal muscle atrophy include cancer, AIDS leading to cachexia, congestive heart disease, and liver diseases.
In addition, muscle atrophy can happen as a result of aging, known as sarcopenia. The decrease in muscle mass due to atrophy results in a loss of muscle strength, which can impact daily activities and overall quality of life.
With age, sarcopenia is a common form of muscle atrophy that is generally irreversible, leading to a sedentary lifestyle. It leads to functional impairments, difficulty in locomotion, balance, and posture, resulting in increased susceptibility to falls and injuries.
However, sarcopenia can be delayed with regular exercise, which helps maintain muscle mass and strength, despite the natural aging process. Exercise can also increase the number of cellular mitochondria, capillary density, and the mass and strength of connective tissues, thus offsetting some of the effects of atrophy.
Physical inactivity, especially during prolonged periods such as bed rest or space flight, significantly contributes to atrophy. In these cases, there is a notable decline in the number and size of muscle cells and a reduction in muscle protein content.
This illustrates the importance of maintaining an active lifestyle to prevent muscle atrophy and preserve muscle strength and function over time.