AP PSYCHOLOGY

Detailed explanation-1: -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-2: -Myelinated neurons conduct impulses faster than unmyelinated neurons because nerve impulses jump over the myelin sheath rather than travel through it, making the distance to the axon terminal shorter. This occurs due to the large proportion of fatty substances that make up the myelin sheath.

Detailed explanation-3: -Answer and Explanation: The type of neuron that conducts the fastest is a myelinated neuron. These neurons are insulated by sheets of lipids called myelin.

Detailed explanation-4: -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. Myelin damage causes several neurological diseases, such as multiple sclerosis.

Detailed explanation-5: -By acting as an electrical insulator, myelin greatly speeds up action potential conduction (Figure 3.14). For example, whereas unmyelinated axon conduction velocities range from about 0.5 to 10 m/s, myelinated axons can conduct at velocities up to 150 m/s.