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': 'Type of necrosis occurring in brain- \nSelect and explain. \nA. Coagulative, B. Liquefactive, C. Fibrinoid, D. Caseous', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Coagulative\xa0necrosis\n\nThis is the most common type of necrosis.\nThis type of necrosis is most frequently caused by sudden cessation of blood flow (ischemia) in organs\xa0such as the heart (MI), Kidney (ATN), adrenal gland, and spleen.\nNote: Brain is the only exception, i.e., It is the only solid organ in which ischemia leads to liquefaction necrosis, not coagulative necrosis.\nIt is also seen with other types of injury e.g., liver necrosis in viral hepatitis, Coagulative necrosis of\xa0skin after burns (Thermal injury).\nWhy there are predominant protein denaturation and no enzymatic digestion?\nHypoxia causes intracellular acidosis (has been explained earlier) → 4 pH results in denaturation\xa0of\xa0proteins which includes not only structural proteins but also enzymes → So, there is no enzymatic\xa0digestion\n\nLiquefactive\xa0necrosis\n\nIt is the necrotic degradation of tissue that rapidly undergoes softening and liquefaction because of the\xa0action of hydrolytic enzymes.\nIt occurs after\n\n1. Infection Le., suppurative inflammation (most common).\n2. Ischemic necrosis in the brain.\nNote: Brain lacks any substantial supportive stroma, so ischemic necrosis in the brain is liquefactive, unlike other\xa0organs where it is coagulative.\n\nMechanism of liquefactive necrosis → Microbes stimulates accumulation of inflammatory cells and these\xa0cells to release lysosomal enzymes.\nCaseous necrosis\nIt is a variant of coagulative necrosis.\nIt is most commonly encountered when cell death is attributable to certain organisms e.g.,\xa0Mycobacterium tuberculosis (TB) and fungi (Histoplasma, Coccidioidomycosis).\nWhy is it called caseous necrosis, not coagulative\xa0necrosis?\nIn contrast to coagulative necrosis where tissue architecture is maintained, in caseous necrosis, the tissue\xa0architecture is completely obliterated. So, it has been called caseous because of its cheesy white\xa0appearance of the area of necrosis.', 'role': 'assistant'}]