Pathology 3240A Chapter Notes - Chapter 1: Epithelium, Coagulative Necrosis, Respiratory Epithelium
4 Dec 2016
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Document Summary
Pathology involves investigation of cause of disease + changes at cellular/tissue/organ level which give rise to presenting signs and symptoms. Etiology = origin of a disease (the why: underlying causes and modifying factors, genetic and environmental. Pathogenesis = steps in the development of disease (the how: how etiological factors trigger cellular changes and give rise to functional/structural abnormalities that characterize disease. Changes are identified morphologically => gross or microscopic. Overview of cellular responses to stress and noxious stimuli. Homeostasis or intracell milieu is kept within a narrow range of physiological parameters. Cells constantly adjust structure and function to accommodate demand and extracell stresses. Principal adaptive responses = hypertrophy, hyperplasia, atrophy and metaplasia. Cell injury results when adaptive capability is exceeded or external stress is harmful. Injury is reversible within certain limits and cell return to baseline stability. Irreversible injury or death occurs when stress is severe, persistent or rapid onset.
