Question

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. multiple choice the brain will slowly degrade and various brain functions will be lost, including motor functions. loss of insulation from myelin will cause neurons of the pns to be hyper - excitable and muscular spasms will result. loss of insulation from myelin will cause neurons of the pns to lose salutatory conduction, resulting in poor muscle function.

Explanation:

1. In Guillain - Barre Syndrome, the immune system attacks the myelin sheath of PNS axons. Myelin acts as an insulator for neurons.
2. When myelin is degraded (loses its insulating property), the neurons in the PNS become hyper - excitable. This hyper - excitability can lead to abnormal electrical signals being sent to the muscles, which in turn can cause muscular spasms.
3. The first option is incorrect because Guillain - Barre Syndrome affects the PNS myelin, not brain degradation related to motor function. The third option is incorrect as the loss of myelin (insulation) does not cause loss of saltatory conduction in the way described to result in poor muscle function directly; rather, the hyper - excitability and spasms are more characteristic.

Answer:

The correct option is: "Loss of insulation from myelin will cause neurons of the PNS to be hyper - excitable and muscular spasms will result" (assuming this is one of the options, let's say Option B for example, so B. Loss of insulation from myelin will cause neurons of the PNS to be hyper - excitable and muscular spasms will result)