Cell adaptation/stress/death Flashcards
hypertrophy
increase size of cell due to increased demand on cells - leads to increase in size of organ
examples: weight lifting, hypertensive heart disease
all cells can do this - to not need to be able to divide
hyperplasia
increase in number of cells - leads to increase in size of organ/tissue
not all cells can do this - must be able to divide
cardiomyocytes and neurons cannot divide
EX: breast tissue increase for milk production, BPH
atrophy
decrease functional demand or impaired nutrition causes decrease in size of existing cells - leads to decrease in size of organ or tissue
ex: nutritional deprivation, diminished endocrine stimulation, denervation, aging
mediated by autophagy
autophagy in atrophy
cell degrades proteins to be used as source of nutrients
metaplasia
replacement of one fully differentiated tissue to another fully differentiated tissue
new cell type better able to withstand stresses in the area
reversible, not neoplastic, but can lead to cancer
ex: cervical changes based on change of hormonal status, GERD changes stratified squamous in esophagus to one that can better deal with acid
how do reactive O2 species hurt the cell
attack proteins, lipids, and DNA - steal an electron, which leads to lipid per oxidation, DNA fragmentation, protein crosslinking
neutralizers of free radicals (antioxidants)
superoxide dismutase
catalase
glutathione peroxidase
vitamins
reversible injury
injury causes damage that can be repaired
irreversible injury
injury causes damage that cannot be repaired:
plasma membrane disruption, massive swelling of mitochondria, fragmentation of ER
necrosis
spectrum of morphologic changes resulting in enzymatic degradation of lethally injured cells
external insult to cell -> lysis -> inflammation
occurs in living tissues
features of necrosis
irreversible cell damage
karyolysis - nuclear membrane lysis and DNA floating in the cell
Pyknosis - nuclear shrinkage
Karyorrhexis - fragmentation of pyknotic nucleus
coagulative necrosis
ischemia leading to myocardial infarction
liquefactive necrosis
bacterial abscess
stroke in the brain
gangrenous necrosis example
peripheral vascular disease causing reduced blood flow to toes
caseous necrosis
TB - macrophages making cheesy material to kill TB