What does the term 'atrophy' describe?

Atrophy refers specifically to the process of muscle tissue shrinking or wasting away, typically due to a lack of use, inadequate nutrition, or underlying medical conditions. This phenomenon is commonly seen in individuals who are immobilized for extended periods, such as patients recovering from surgery or those with conditions that prevent regular physical activity. As muscle fibers decrease in size and number, the overall strength and functionality of the muscle diminish, which highlights the critical implications of maintaining physical activity for muscle health. The other options describe processes that are opposite to atrophy, such as growth or strengthening of muscle tissue, which emphasizes the correct identification of atrophy as a decline rather than an increase in muscle mass or capabilities.