Here's a summary of the differences between reversible and irreversible cell injury: Reversible cell injury occurs when cells are exposed to stress or injury but can recover* if the damaging stimulus is removed. Key features include cellular swelling (due to impaired ion pumps), fatty change (accumulation of lipids), and mitochondrial swelling. The cell's nucleus remains intact, and the cell membrane is not severely damaged. Irreversible cell injury occurs when the damage is too severe for the cell to recover, leading to cell death. This is characterized by severe mitochondrial damage (leading to ATP depletion), rupture of lysosomes (releasing digestive enzymes), and profound disturbances in membrane function. The nucleus undergoes changes like pyknosis (shrinkage), karyorrhexis (fragmentation), and karyolysis* (dissolution). The cell membrane is irreversibly damaged, leading to leakage of cellular contents. In essence, the main difference is the ability to recover. Reversible injury allows the cell to return to normal function, while irreversible injury leads to the cell's demise through processes like necrosis or apoptosis.