Consequences of Hypoxic injury

Consequences of hypoxic injury:

• As the oxygen tension within the cell falls, there is loss of oxidative phosphorylation and decreased generation of ATP. The depletion of ATP results in failure of the sodium pump, leading to efflux of potassium, influx of sodium and water, and cell swelling. 
• There is also influx of Ca2+, with its many deleterious effects. 
• There is progressive loss of glycogen and decreased protein synthesis. The functional consequences may be severe at this stage.
• The cytoskeleton disperses, resulting in the loss of ultrastructural features such as microvilli and the formation of blebs at the cell surface. 
• Myelin figures derived from degenerating cellular membranes, may be seen within the cytoplasm or extracellularly. They are thought to result from unmasking of phosphatide groups, promoting the uptake and intercalation of water between the lamellar stacks of membranes. 
• At this time the mitochondria are usually swollen, as a result of loss of volume control in these organelles; the ER remains dilated; and the entire cell is markedly swollen, with increased concentrations of water, sodium, and chloride and a decreased concentration of potassium. 
• If ischemia persists, irreversible injury and necrosis ensue.