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': 'Aschoff cells are - \nSelect and explain. \nA. Fibroblasts, B. Monocytes, C. Neutrophils, D. Lymphocytes', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The monocytes migrate to tissues and become part of the tissue (fixed) macrophages.\nBlood macrophages → Monocytes\nTissue macrophages → Histiocytes\n\nTissue macrophages (histiocytes) in different tissue are mentioned below –\n\nLung: ‘Alveolar macrophages’ or ‘Dust’ cells\nPlacenta: Hofbauer cells\nBrain: Microglia\nKidney: Mesangial cells\nLiver: Kupffer cells\nSpleen: Littoral cells\nBone: Osteoclasts\nSynovium: Type-A lining cells\nSkin: Langerhans cells\nSpleen: Red pulp sinusoidal lining cells\nConnective tissue: Histiocytes (tissue macrophages)\nL The lifespan of monocytes in circulation is 1-3 days whereas tissue macrophages have a life span of 3 months\xa0to years', 'role': 'assistant'}]