Final answer:
The question pertains to the concept of hypertrophy, which is the increase in size of muscle tissue due to exercise and increased capillarization. Hypertrophy involves adding structural proteins to muscle fibers, while the opposite process, atrophy, involves the loss of muscle mass.
Step-by-step explanation:
The student's question is about muscle tissue response to different conditions. Specifically, the question seems to focus on the increase in fiber size due to increased capillarization. This is a reference to the concept of hypertrophy, which is the increase in the size of a structure or tissue. Hypertrophy in muscle tissue can result from exercise as it leads to the addition of structural proteins and can be accompanied by increased capillarity. Hyperplasia, on the other hand, is the process by which there is an increase in the number of cells, such as can be seen in smooth muscle like the uterus. The opposite of hypertrophy is atrophy, which involves the loss of muscle mass. Atrophy can occur with disuse of muscles or as part of the aging process, known as sarcopenia. Unlike hypertrophy and atrophy, hyperplasia alters the number of cells, while the former change the size of existing muscle fibers.