Why conduction of nerve is faster in myelinated nerve fibre

In myelinated nerve fibre, the action potential is conducted from node to node in jumping manner. This is because the myelinated nerve fibre is coated with myelin sheath. The myelin sheath is impermeable to ions. As a result, the ionic exchange and depolarisation of nerve fibre is not possible along the whole length of nerve fibre. It takes place only at some point, known as nodes of Ranvier. Thus, due to this jumping of impulse fom node to node, impulse travels fater down the axon of neuron.