What characterizes hyperplasia?

Hyperplasia is characterized by the excessive proliferation of normal cells within a tissue, leading to an increase in the number of cells. This process typically occurs in response to a stimulus, such as hormonal changes or increased demand on the tissue, and is a regulated process that maintains normal cellular function and architecture.

In various tissues, hyperplasia can serve as a compensatory mechanism. For instance, in the case of muscle cells, an increase in workload may lead to hyperplasia to manage the additional stress. Importantly, the cells produced in hyperplasia are normal in appearance and function, distinguishing this condition from malignancies or other dysplastic processes, where the cells may be abnormal.

This phenomenon can be contrasted with processes such as hypertrophy, where there's an increase in cell size rather than cell number, or atrophy, which involves a reduction in both cell number and size. Thus, while the other options suggest changes in cell number or structure that do not align with the definition of hyperplasia, the correct answer highlights the specific increase in cell numbers while maintaining normal cellular appearance and function.