What process causes hyperplasia?

Hyperplasia is a process characterized by an increase in the number of cells in a tissue or organ, leading to its enlargement. This occurs primarily through increased cellular division, which is the correct answer to the question.

In various physiological and pathological contexts, hyperplasia can occur as a response to stimuli such as hormonal changes, increased demand on a tissue, or injury. For example, in cases where there is a hormonal stimulus, such as during pregnancy, the breast tissue undergoes hyperplasia to accommodate milk production. Similarly, in response to chronic irritation or inflammation, tissues may also exhibit hyperplastic growth as part of their adaptive response.

In contrast, cell size growth refers to hypertrophy, where individual cells increase in size instead of increasing in number, which is not the definition of hyperplasia. A reduction in cell size indicates atrophy, a different process where tissues shrink due to loss of cell mass. Replacement of mature cells generally describes processes like regeneration or differentiation, which do not specifically account for the increase in cell number associated with hyperplasia.

Therefore, increased cellular division is the fundamental mechanism behind hyperplasia, emphasizing the role of cell proliferation in tissue growth and adaptation to various stimuli.