Aneuron has three basic parts: the dendrites, the cell body, and the axons. some neurons have a fatty layer covering called around their axons. this layer isn't continuous, and the gaps are called. the action potential jumps through these gaps to the transmission.

A neuron has three basic parts: the dendrites, the cell body, and the axons. Some neurons have a fatty layer covering called The myelin sheath around their axons. This layer isn’t continuous, and the gaps are called nodes of Ranvier . The action potential jumps through these gaps to speed up the transmission.

The correct answer will be-

1. Myelin sheath

2. Nodes of Ranvier

3. Speed up

Explanation:

The neurons are the functional unit of the nervous system which acts to transmit the signals in the form of electrical impulses.

The axon of a neuron is covered by the layer composed of fats and glycoproteins which help to provide insulation to the neurons called myelin sheath. The myelin sheath also helps increase the transmission of the generated action potential through neurons.

The myelin sheath is not continuous at the axons but is reduced at certain points called nodes of Ranvier. These nodes of Ranvier contain the sodium voltage gates.  

Thus, Myelin sheath, Nodes of Ranvier and Speed up are correct.