Reversible cell injury:- → Hypoxia is the most common cause of cell injury. → Oxygen is an important requirement of mitochondria, for the formation of ATP, therefore hypoxia will result in earliest involvement of mitochondria, resulting in decreased formation of ATP. → Important organelles affected areCell membranes (require ATP for functioning of Na+ - K+ pump) Endoplasmic reticulum (require ATP for protein synthesis) Nucleus.→ Swelling of organelles like endoplasmic reticulum, results in decreased protein synthesis. → Bleb results due to outpouching from the cell membrane to accommodate more water. → Loss of microvilli. → Formation of cellular organelle like endoplasmic reticulum. These are composed of phospholipids. →Myelin figures are intracellular whorls of laminated lipid material. ​​When these myelin figures are present in membrane-bound structure, containing lysosome enzymes, these are known as myeloid bodies.