In Guillain-Barre syndrome, the immune system attacks and degrades the myelin sheath of PNS axons. Predict the effect this will have on nerve impulse and motor function.
A. Motor signals will not be sent from the brain down the efferent pathway because the brain cannot generate them.
B. Lost insulation from myelin will cause neurons of the PNS to be hyper-excitable and muscular spasms will result.
C. The brain will slowly degrade and various brain functions will be lost, including motor functions.
D. Lost insulation from myelin will cause neurons of the PNS to lose saltatory conduction, resulting in poor muscle function.
Answer: D
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