what is the functional advantage of the myelin sheath
Myelin The main purpose of a myelin sheath is to increase the speed at which impulses propagate along the myelinated fiber. Along unmyelinated fibers, impulses continuously move as waves, but, in myelinated fibers, they "hop" or propagate by saltatory conduction. Myelin decreases capacitance and increases electrical resistance across the cell membrane (the axolemma). Thus, myelination prevents the electric current from leaving the axon. It has been suggested that myelin permits larger body size by maintaining agile communication between distant body parts.[6]