Irreversible injury is due to

Irreversible Injury: Defect in membrane function in general, and plasma membrane in particular, is the most important event in irreversible cell injury in ischaemia. Oxygen deprivation causes shift of calcium from mitochondria and endoplasmic reticulum into the cytosol. Increased level of calcium in the cytosol activates endogenous phospholipases from ischaemic tissue which degrade membrane phospholipids progressively which are the main constituent of the lipid bilayer membrane. An alternate hypothesis is decreased replacement-synthesis of membrane phospholipids due to reduced ATP. Myelin figures & cellular swelling are the changes seen in Reversible cell injury.