Discuss the neuroglial cells that form the myelin sheaths in the CNS and the PNS and discuss some of their differences

Question

What will be an ideal response?

Answer 1

Oligodendrocytes wrap the axons of certain neurons in the CNS. The wrapped processes, collectively called myelin, form repeating processes that create a myelin sheath. Schwann cells form the myelin sheath around PNS axons. Although both oligodendrocytes and Schwann cells wrap axons in successively tighter bands, they do so in opposite directions from one another: Schwann cells wrap outward away from the axon while oligodendrocytes wrap inward toward the axon. Other differences between oligodendrocytes and Schwann cells include the presence or absence of a neurolemma, the number of axons myelinated by a single glial cell, and the timing of myelination. Schwann cells have a neurolemma, whereas oligodendrocytes do not. A single Schwann cell can only myelinate one axon, whereas one oligodendrocyte can help myelinate many axons. Schwann cells start myelinating axons earlier in fetal development than oligodendrocytes.