AP PSYCHOLOGY

Detailed explanation-1: -Myelin can greatly increase the speed of electrical impulses in neurons because it insulates the axon and assembles voltage-gated sodium channel clusters at discrete nodes along its length.

Detailed explanation-2: -Myelin speeds up impulses The myelin sheath contains periodic breaks called nodes of Ranvier. By jumping from node to node, the impulse can travel much more quickly than if it had to travel along the entire length of the nerve fibre.

Detailed explanation-3: -The fastest signals in our bodies are sent by larger, myelinated axons found in neurons that transmit the sense of touch or proprioception – 80-120 m/s (179-268 miles per hour).

Detailed explanation-4: -Q: “Why does an axon diameter increase speed?” There are two primary reasons: more motive force and less resistance. A larger diameter means there can be more ion channels around the axon, which means that there are more ion channels per each length of axon.

Detailed explanation-5: -These are the gaps formed between the myelin sheath where the axons are left uncovered. Because the myelin sheath is largely composed of an insulating fatty substance, the nodes of Ranvier allow the generation of a fast electrical impulse along the axon. This rapid rate of conduction is called saltatory conduction.