Which glial cell is primarily involved in disposing of debris in the CNS?

Which glial cell is primarily involved in disposing of debris in the CNS?

• A. Astrocytes
• B. Oligodendrocytes
• C. Microglia
• D. Ependymal cells

Answer: (C)

The main concept here is how the CNS clears debris. Microglia act as the brain’s resident immune cells and function like macrophages within the nervous system. They continually survey neural tissue and, when they encounter debris from injury or dead cells, they phagocytose it—engulfing and digesting fallen material to keep the environment clean. They can become activated, extend processes to reach sites of damage, and release signaling molecules to coordinate repair and inflammation. In contrast, astrocytes mainly support neurons, regulate the blood-brain barrier, maintain ion and neurotransmitter balance, and form scar tissue after injury. Oligodendrocytes insulate axons by forming myelin, and ependymal cells line the ventricles and help circulate cerebrospinal fluid. Because of their role as phagocytic cleaners of the CNS, microglia are the best choice for disposal of debris.

The main concept here is how the CNS clears debris. Microglia act as the brain’s resident immune cells and function like macrophages within the nervous system. They continually survey neural tissue and, when they encounter debris from injury or dead cells, they phagocytose it—engulfing and digesting fallen material to keep the environment clean. They can become activated, extend processes to reach sites of damage, and release signaling molecules to coordinate repair and inflammation.

In contrast, astrocytes mainly support neurons, regulate the blood-brain barrier, maintain ion and neurotransmitter balance, and form scar tissue after injury. Oligodendrocytes insulate axons by forming myelin, and ependymal cells line the ventricles and help circulate cerebrospinal fluid. Because of their role as phagocytic cleaners of the CNS, microglia are the best choice for disposal of debris.