MEDICAL PHYSIOLOGY

Detailed explanation-1: -Conduction velocity is high in myelinated nerve fibre with the greater diameter. So, the given statement is false.

Detailed explanation-2: -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-3: -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.

Detailed explanation-4: -Large-diameter nerve fibers conduct impulses much faster than small-diameter fibers.

Detailed explanation-5: -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.