Final answer:
The primary mechanism of hyperplasia is an increase in cell number in response to hormonal stimuli or growth factors, with the causative factor often being persistent stimulation or injury requiring tissue adaptation.
Step-by-step explanation:
The primary mechanism of cellular adaptation in hyperplasia involves an increase in cell number due to up-regulation of cellular activity, often in response to hormonal stimulation or growth factors. The causative factor for hyperplasia typically includes persistent cellular stimulation or injury that requires the tissue to undergo adaptive increases in cell number to maintain normal tissue function.
Cells sensitive to hormonal cues can either amplify (up-regulate) or diminish (down-regulate) their response based on hormone levels. A higher concentration of a hormone will likely bind more receptors on the target cells, thus leading to a greater cellular response, such as increased cell division in hyperplasia. In this context, growth factors are external signals that stimulate cell division and growth, which, if left unchecked, can potentially lead to abnormal growth patterns or cancerous changes.