NLN PAX Practice Exam 2025 – Complete Study Guide

When muscles atrophy, they undergo a process where their size and strength diminish, leading to a condition often described as "wasting away." Atrophy can occur due to a variety of factors, including lack of use, immobilization, aging, and certain medical conditions. This decrease in muscle mass occurs because the body is not using those muscle fibers as much, leading to a reduction in protein synthesis and an increase in the breakdown of muscle proteins. As a result, the muscles become weaker and smaller over time, impacting physical strength and function.

In contrast, conditions such as stiffening, fatigue, or gaining strength do not accurately characterize muscle atrophy. Stiffness typically relates to an increase in muscle tone or tension rather than a reduction in muscle mass. Fatigue is often a temporary condition resulting from overuse or exertion, rather than a change in muscle size. Lastly, gaining strength is the opposite of atrophy, indicating a process of muscle growth and development through exercise and increased demand on the muscles.