Which glial cell type forms myelin in the central nervous system?

Which glial cell type forms myelin in the central nervous system?

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

Answer: (D)

Myelin in the central nervous system is formed by oligodendrocytes. These glial cells extend their processes to multiple nearby axons and wrap segments of each with myelin, creating insulating sheaths that speed up electrical signals through saltatory conduction between the nodes of Ranvier. This CNS specialization contrasts with astrocytes (support and ion balance), microglia (immune cells), and ependymal cells (line ventricles and help with CSF). In the peripheral nervous system, Schwann cells carry out myelination, but in the CNS the myelin-producing cells are oligodendrocytes.

Myelin in the central nervous system is formed by oligodendrocytes. These glial cells extend their processes to multiple nearby axons and wrap segments of each with myelin, creating insulating sheaths that speed up electrical signals through saltatory conduction between the nodes of Ranvier. This CNS specialization contrasts with astrocytes (support and ion balance), microglia (immune cells), and ependymal cells (line ventricles and help with CSF). In the peripheral nervous system, Schwann cells carry out myelination, but in the CNS the myelin-producing cells are oligodendrocytes.