Question

Slow conduction velocity is seen with which of the following nerve fibers?

• A. Preganglionic autonomic nerve fibers
• B. Postganglionic autonomic nerve fibers
• C. Motor nerves
• D. Sympathetic nerve fibers

Answer 1

The Correct Option is B

Nerve fibers vary in their conduction velocities due to differences in diameter, myelination, and function. To determine which fiber type has a slow conduction velocity, it's important to understand the characteristics of each:

• Preganglionic autonomic nerve fibers: These fibers are myelinated and generally have a moderate conduction velocity.
• Postganglionic autonomic nerve fibers: These fibers are unmyelinated and possess a small diameter, resulting in slow conduction velocities compared to other nerve fibers.
• Motor nerves: Typically, these are large-diameter, myelinated A-alpha fibers with very fast conduction velocities.
• Sympathetic nerve fibers: These include both preganglionic and postganglionic fibers, where preganglionic are myelinated with moderate velocity, and postganglionic are unmyelinated with slow velocity.

Among the options, the Postganglionic autonomic nerve fibers are identified as having slow conduction velocity due to their lack of myelination and small diameter.