Which term describes the excessive proliferation of normal cells in their normal arrangement?

The term that accurately describes the excessive proliferation of normal cells in their normal arrangement is hyperplasia. Hyperplasia refers to an increase in the number of cells in a tissue or organ, which results in its enlargement. Importantly, in hyperplasia, the cells maintain their normal structure and organization, meaning they proliferate in the usual layout rather than in a disordered or chaotic manner.

This condition can occur in response to various stimuli, such as hormonal signals or increased functional demand on a tissue. For example, during pregnancy, the breast tissue undergoes hyperplasia to prepare for lactation, demonstrating that this process is both a physiological and growth-related adaptation.

In contrast, dysplasia involves disordered growth with potential abnormalities in cell size, shape, and arrangement, often indicating a pre-cancerous state. Atrophy pertains to the reduction in size and function of an organ or tissue due to a decrease in cell size or number, generally from disuse or lack of nourishment. Hypertrophy describes an increase in the size of existing cells, leading to tissue enlargement without necessarily increasing the overall cell count. Thus, hyperplasia is the only term among the options that specifically denotes the normal arrangement and increased cell numbers, solidifying its position as the accurate answer.