Unformatted text preview: (salutatory conduction) from node to node. In this fashion, the myelin sheath provides insulation between adjacent nerve fibers, preventing the crossover of one nerve impulse to an adjacent axon. In the CNS, the axons of neurons are insulated by oligodendrocytes. The myelin sheath is formed when a process extended by the oligodendrocyte wraps around an axon. Many axons may be myelinated by multiple processes from a single oligodendrocyte. The white and gray matter of the brain and spinal cord are distinguished by the presence or absence of myelin sheaths: • White matter contains the myelinated axons of neurons. (The white color is from the myelin sheaths.) • Gray matter contains the unmyelinated portions of neurons (cell bodies, dendrites, and axon terminals), unmyelinated axons, and neuroglia....
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- Spring '10
- Schwann Cell, myelin sheath, Schwann Cells