cell injury Flashcards
structures and processes that maintain cell viability include:
- plasma membrane
- mitochondria
- macromolecular synthesis (RNA rep, RNA transcription, translation, cell wall (peptidoglycan) synthesis, fatty acid (lipid) biosynthesis
- nucleus
mechanisms of cell injury
- ATP depletion
- generation of ROS (oxidative stress)
- loss of Ca homeostasis
- altered plasma membrane perm
- mitochondrial/DNA/protein damage
decreased oxygen (hypoxia) or no oxygen (anoxia) is due to:
- impaired absorption of oxygen
- decreased blood flow (ischemia)
- disease of blood or BVs
- inadequate oxygenation of the blood
decreased oxygen due to ischemia impairs ____ in the mitochondria, which leads to a decrease in ____
oxidative phosphorylation; ATP
reduced ATP reduces the ability of the plasma membrane to _____; there is impaired function of the _____ which leads to _____
maintain homeostasis; plasma membrane ATP-dependent Na pump; increased influx of Na, Ca, and water and increased efflux of K (net gain of solute and isoosmotic gain in cytoplasmic water)
gain in isoosmotic water leads to:
- cell swelling with formation of cell surface blebs
- mitochondria swelling
- swelling of ER
swelling of the ER leads to:
detachment of ribosomes/dissociation of polysomes and a decrease in protein synthesis (which can lead to increased lipid deposition)
reduced oxidative phosphorylation leads to increased _____ which produces ____
anaerobic glycolysis; lactic acid and inorganic phosphates
an increase in lactic acid decreases ____ leading to ____
intracellular pH; chromatin clumping
_____ (a mechanism of cell damage by ROS) affects the ____ which plays a role in maintaining homeostasis
lipid peroxidation (oxidative degradation of lipids); cell membrane (disrupted membrane makes it more permeable)
_____ is a final common pathway of cell injury
increase cytoplasmic Ca
high levels of Ca will activate various _____ such as:
degradative enzymes; phospholipases, proteases, endonucleases, ATPase
degree of cell injury is determined in part by:
- cell type/physiologic state of cell
- intensity/duration of insult
- number of exposures to etiologic agent
common etiologies of reversible (sub-lethal) cell injury include:
toxins, infectious agents, hypoxia, and thermal injury
reversible cell injury includes ____ and ____ morphology changes
hydropic ; fatty
morphologic changes in necrosis include: cell ____, ____ yielding a glassy homogenous pink staining cytoplasm, ____ breakdown which may result in a _____ cytoplasm, ____ changes, and ______
- cell swelling
- protein denaturation
- organelle breakdown- vacuolated cytoplasm
- nuclei changes (karyolysis/pyknosis/karyorrhexis/total loss)
- inflammation (acute or granulomatous)
morphologic types of necrosis
- coagulative
- liquefactive
- caseous
- enzymatic (fat)
the type of necrosis is dependent upon patterns of _____ of cells and ECM, the type of ____, and by _____ when present
enzymatic degradation; necrotic debris; bacterial products
in coagulative necrosis (most common form), _____ are coagulated; the ____ is lost, but the _____ of the cell is retained for a short time prior to being removed by the inflammatory response
cytoplasmic proteins; nucleus; eosinophilic outline
in liquefactive necrosis, the tissue is totally digested by the release of _____ during the ______
lysosomal enzymes; acute inflammatory response
liq necrosis often assoc with ____ or _____ (abscesses and wet gangrene), also seen in the _____
focal bacterial; fungal infections; central nervous system (brain)
caseous necrosis assoc with _____ infection; the tissue has a ____ and ____ appearance on gross examination
M. tuberculosis; white; cheesy
caseous necrosis microscopically characterized by ______ material within a ring of _____ and loss of _____
amorphous pink granular; granulomatous inflammation; tissue architecture
fat necrosis common in ____ to the breast or in cases of _____; adipose tissue has a _____ gross appearance; dead adipocytes give a _____ histologic appearance
trauma; pancreatitis; chalky white-yellow; “soap bubble”
