Final answer:
The three possible mechanisms for muscle hypertrophy are mechanical tension, metabolic stress, and muscle damage. The correct answer for the described options is 2). Option A, Option B, Option C, correlating with the mechanisms mentioned.
Step-by-step explanation:
Muscle Hypertrophy Mechanisms
Current research suggests three possible mechanisms for inducing muscle hypertrophy: mechanical tension, metabolic stress, and muscle damage. Each of these plays a role in the process by which muscle fibers grow in size and strength.
Mechanical tension involves the force produced during resistance exercises. When muscles are stretched under load, such as when lifting weights, they adapt by getting stronger and often bigger. Metabolic stress is associated with the buildup of metabolites, such as lactate, from anaerobic metabolism, which is thought to contribute to muscle growth by inducing cellular swelling and other responses. Muscle damage occurs as a result of strenuous exercise that creates microscopic tears in muscle fibers; their repair process involves the fusion of satellite cells to the fibers, contributing to increases in muscle cross-sectional area.
While muscle hypertrophy increases muscle size, muscle atrophy is the decrease in muscle mass, which can result from disuse, malnutrition, or certain diseases. Muscle atrophy occurs when the rate of muscle protein breakdown exceeds the rate of muscle protein synthesis. The correct option that describes the three mechanisms of muscle hypertrophy is 2). Option A, Option B, Option C as it best fits with the provided mechanisms: mechanical tension (Option A), metabolic stress (Option B), and muscle damage (Option C).