This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Introduction to Central Nervous System, Subject name: Physiology
Scavenger cell in the CNS is: 
Select and explain. 
A. Astrocytes, B. Microglia, C. Oligodendrocyte, D. Schwann cell
B: Microglia
Answer: B: Microglia 
Explanation: Microglia is the only cell that is borne out of CNS and moves into the CNS. It is formed from monocyte lineage in the bone marrow. It is physiologically and embryologically unrelated to other neural cell types It has phagocytic function hence known as "scavenger cell" in the CNS.