VPT 61 Diseases at Cellular Level A.pdf

Topic : Diseases at Cellular level Normal Cell Cellular Adaptation Cell Injury Consequences of cellular injury Causes of cell injury Reversibility and irreversibility of cellular injury Normal Cell “All organ injuri...

Topic : Diseases at Cellular level Normal Cell Cellular Adaptation Cell Injury Consequences of cellular injury Causes of cell injury Reversibility and irreversibility of cellular injury Normal Cell “All organ injuries start with structural or molecular alterations in cells” concept began by Virchow in 1800's. present day study of disease attempts to understand how cells react to injury, often at the subcellular ormolecular level, and how this is manifested in the whole animal Normal Cell to understand pathology, review normal structure and function of cells (“you cannot appreciate the abnormal before you adequately understand the normal”) CELL ADAPTATION, CELL INJURY and CELL DEATH (DEFINITIONS AND TERMINOLOGY) 1) Homeostasis cells are able to maintain normal structure and function (eg ion balance, pH, energy metabolism) in response to normal physiologic demands. 2) Cellular Adaptation as cells encounter stresses, either excessive physiologic demand or some pathologic stimuli, they may make functional or structural adaptations to maintain viability / homeostasis. cells may respond to these stimuli by either increasing or decreasing their content of specific organelles. adaptive processes: atrophy, hypertrophy, hyperplasia and metaplasia are forms of adaptation.  CELL ADAPTATION, CELL INJURY and CELL DEATH (DEFINITIONS AND TERMINOLOGY) 3) Cell Injury if the limits of adaptive response are exceeded, or in certain instances when adaptation is not possible, a sequence of events called cell injury occurs a) Reversible Cell Injury