Cell Adaptation
The reliability and functionality of cells have a major effect on the human body. McCance and Huether (2019) elaborated that cells must adapt to their surroundings to protect and prevent injury. Thus, hypertrophy refers to an adaptive increase in cell mass, organ, or tissue, which does not arise from the proliferation of the cell (Hyperplasia). Common hypertrophy examples are physiological hypertrophy, such as uterus enlargement and muscle increase, hepatocyte xenobiotic induction, which causes hepatocyte cytoplasm expansion, hypertrophy of the uterus, and myocardial hypertrophy (Wallig & Janovitz, 2018).
Hyperplasia is an increase in cells per unit within a tissue, which normally occurs with hypertrophy. Some of the examples include urothelial hyperplasia found in renal pelvic, squamous epithelium hyperplasia, endometrial hyperplasia, and bronchial hyperplasia (Suttie, 2015). Sometimes, hyperplasia and hypertrophy occur at the same time.
Hyperplasia and hypertrophy are physiological responses to stimuli, where cells are subject to the normal mechanisms of regulatory control. However, some cases happen as pathological responses when a growth factor creates the stimuli (Kumar, 2014). Notably, processes are manipulated by growth hormones and are likely to stop in the absence of stimuli.
Dysplasia is a disordered epithelium growth that is common with cell orientation, shape and size loss, and mitotic figures. Dysplasia is not categorized as a true adaptation since it is considered a type of hyperplasia. In addition, this process occurs together with hypertrophy (Porth & Gaspard, 2015). Metaplasia is a reversible replacement of a mature cell to a less differentiated cell. An example is the replacement of bronchial lining columnar ciliated epithelial cells with squamous epithelial cells (McCance & Huether, 2019). Both metaplasia and dysplasia are reversible when the inciting stimulus is eliminated.
