This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Irreversible injury is due to \nSelect and explain. \nA. Decrease in ATP, B. Defective membrane function, C. Myelin figures, D. Cellular swelling', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 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.\nMyelin figures & cellular swelling are the changes seen in Reversible cell injury.', 'role': 'assistant'}]