How does tissue hypoxia precipitate necrosis?

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Multiple Choice

How does tissue hypoxia precipitate necrosis?

When oxygen supply falls, cells can no longer run oxidative phosphorylation, so ATP production drops drastically. That energy shortfall cripples energy-dependent ion pumps like Na+/K+ ATPase, allowing sodium and water to rush into the cell and causing cellular swelling. Calcium homeostasis also collapses, leading to elevated intracellular calcium that activates enzymes damaging membranes, cytoskeletal elements, and mitochondria. With ongoing energy failure, membranes become increasingly permeable, organelles swell, and eventually the membrane ruptures, releasing intracellular contents. This sequence—ATP depletion, pump failure, ionic and osmotic imbalance, and progressive membrane damage—drives the cell toward necrosis if the hypoxic insult persists. Why the other ideas don’t fit: hypoxia does not increase ATP production or stabilize pumps; it creates a deficit. It does not cause hyperoxia; opposite oxygen conditions apply. It certainly does not improve cell viability; it leads toward irreversible injury with necrosis when prolonged.

When oxygen supply falls, cells can no longer run oxidative phosphorylation, so ATP production drops drastically. That energy shortfall cripples energy-dependent ion pumps like Na+/K+ ATPase, allowing sodium and water to rush into the cell and causing cellular swelling. Calcium homeostasis also collapses, leading to elevated intracellular calcium that activates enzymes damaging membranes, cytoskeletal elements, and mitochondria. With ongoing energy failure, membranes become increasingly permeable, organelles swell, and eventually the membrane ruptures, releasing intracellular contents. This sequence—ATP depletion, pump failure, ionic and osmotic imbalance, and progressive membrane damage—drives the cell toward necrosis if the hypoxic insult persists.

Why the other ideas don’t fit: hypoxia does not increase ATP production or stabilize pumps; it creates a deficit. It does not cause hyperoxia; opposite oxygen conditions apply. It certainly does not improve cell viability; it leads toward irreversible injury with necrosis when prolonged.

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