Question

sammy has recently noticed difficulties with his coordination, and his reaction time seems slower. the physician tells sammy that it is likely a problem with the myelin sheath on some axons. what could be the problem with the myelin sheath based on sammys symptoms? the myelin sheath is starting to cover the dendrites. the amount of myelin sheath on some axons is declining. the myelin sheath on the axons is multiplying at a faster than normal rate. the sodium ions are being blocked by the myelin sheath.

Explanation:

The myelin sheath speeds up nerve - impulse transmission along axons. A decline in the amount of myelin sheath on axons can lead to slower nerve - impulse conduction, resulting in coordination problems and slower reaction times. Myelin sheath normally covers axons, not dendrites. Faster multiplication of myelin sheath would not cause these symptoms. Myelin sheath does not block sodium ions in a way that would cause these symptoms.

Answer:

The amount of myelin sheath on some axons is declining.