Question

Explain why ‘saltatory conduction’ allows signals to propagate more rapidly along the axon (4pts)

Answer 1

>>Saltatory conduction which occurs widely in the myelinated axons of vertebrates and also in the medial myelinated giant fibres of organisms such as earthworm,is the process of propagation of action potentials along the myelinated axons which involves opening and closing of ion channels at the nodes of Ranvier,thus increasing the speed of conduction of action potentials in the axon.

>>The reason of why saltatory conduction increases the rate at which action potentials propagated is due to a restriction of myelinated axons.

>>Between the myelinated internodes,there occurs the unmyelinated nodes of ranvier.And the myelinated axons only allows the action potentials to occur at these unmyelinated nodes of ranvier.

>>When the sodium rushes into these nodes,an electrical force will be generated.This electrical force will push the ions inside the axon.And this rapid conduction of electrical signals will reach to the next node and there another action potential will be generated.In this way,saltatory conduction will allows the long distance propagation of electrical signals at high rates.

As we know that action potentials propagates through axons by "jumping",but the saltatory conduction is a rapid,instantaneous phenomenon that occurs in the myelinated axons.