Schwann Cells: These are like workers who install insulation on wires. Schwann cells produce myelin in peripheral nervous system.
Nodes of Ranvier: These are gaps in myelin sheath along axon which help increase speed at which electric impulses propagate along axon - think about them as boosters or amplifiers for signal transmission.
Multiple Sclerosis (MS): This disease damages myelin sheaths around nerves in central nervous system disrupting communication between brain and body, similar to how a damaged insulation would disrupt electricity flow.