PODI3301 Lecture 1: General-Pathology
25 Jul 2018
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Document Summary
Ischemia: interference w blood supply to tissues, generally due to blood vessels w a resultant damage or dysfunction of tissue. Ischemia is an absolute or relative shortage of the blood supply to an organ. Hypoxia: oxidative phosphorylation (mitochondria) dec intracellular atp. Mitochondrial function, inc membrane permeability, morphologic deterioration injury. Loss of plasma membrane regulation ionic imbalance influx of fluid. Generalised swelling, clumping of nuclear chromatin, aggregation of intramembranous particles, autophagy of lysosomes, er swelling, dispersion of ribosomes, mitochondrial swelling, blebing of pm: explain why ischemia injures tissues faster than hypoxia. O2 is bound to haemoglobin in rbc"s, insufficient blood supply causes tissue to become hypoxic. Ichemia/reperfusion injury reintroduction of oxygen increases free radicals which can accelerate necrosis. Free radicals degrade na"s and nuclear molecules, initiate autocatalytic reactions, dna lesions, cross-linking of proteins, lipid peroxidation of membranes. Cell injury: can be ir/reversible (depending if injurious stimulus is removed in time), injured cell can lose its specialised function.
