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Cellular Injury During Ischemia
Deterioration of Ion Gradients
 Inadequate
energy supply leads to deterioration of ion gradients.
Anoxic depolarization (equilibration of intracellular and
extracellular ions) causes potassium to leave the cell and
sodium, chloride, and calcium ions to enter. It also
stimulates the massive release of the amino acids glutamate
and aspartate, excitatory neurotransmitters in the brain.
Glutamate further activates sodium
and calcium ion channels in the neuron membrane.
As sodium and calcium ions rapidly
accumulate within the cells, accompanied by an inflow of water,
cytotoxic edema causes rapid swelling of neurons and glia.
Activation of calcium channels
results in further influx of calcium into the cell.
One of the most intensely studied calcium channels is the
N-methyl-D aspartate (NMDA) channel.
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Stroke Education
