Final answer:
Muscle hypertrophy can be induced through resistance exercise that increases sarcomeres and myofibrils, hormonal influences like testosterone and growth hormone which stimulate protein synthesis, and cellular adaptation to muscle damage which leads to an increase in muscle fiber size.
Step-by-step explanation:
Muscle hypertrophy is an increase in muscle mass and strength. Three mechanisms that can induce this process are:
- Resistance Exercise: This type of exercise contributes to muscle hypertrophy by increasing the number of sarcomeres and myofibrils within muscle fibers, leading to greater muscle mass and strength.
- Hormonal Influence: Hormones such as testosterone and growth hormone (GH) can stimulate hypertrophy. GH acts indirectly by stimulating liver production of insulin-like growth factors (IGFs), which promote the uptake of amino acids for the synthesis of new proteins in muscles.
- Cellular Adaptation: Strenuous exercise leads to muscle damage, which requires repair. This repair process can lead to an increase in muscle fiber size as the muscle adapts to the increased workload.
It's important to note that hypertrophy differs from hyperplasia, which is an increase in the number of cells, such as observed in smooth muscle tissue.