Final answer:
Hypertrophy is the enlargement of skeletal muscle fibers in response to overcoming force from high volumes of tension. It involves an increase in the size of individual muscle fibers through the production of sarcomeres and myofibrils. This process does not change the number of muscle fibers.
Step-by-step explanation:
The enlargement of skeletal muscle fibers in response to overcoming force from high volumes of tension is called hypertrophy. Hypertrophy refers to the increase in the size of individual muscle fibers and is a result of increased production of sarcomeres and myofibrils within the muscle fibers. This leads to increased mass and bulk in the skeletal muscle.
Factors like hormones, stress, and resistance training can stimulate hypertrophy in skeletal muscles. For example, bodybuilders often have a large number of fast glycolytic (FG) fibers and relatively few slow oxidative (SO) and fast oxidative (FO) fibers, contributing to their muscle hypertrophy.
Hypertrophy is different from hyperplasia, which is the process of one cell splitting to produce new cells. In hypertrophy, the existing muscle fibers increase in size, but the number of muscle fibers does not change.