Which fiber type is associated with fast, sharp pain?

Which fiber type is associated with fast, sharp pain?

• A. A-delta fibers
• B. C fibers
• C. Both A-delta and C fibers
• D. Neither fiber type conducts pain

Answer: (A)

Fast, sharp pain is carried by A-delta fibers. These thinly myelinated fibers conduct signals quickly, producing the immediate, localized pain you feel right after a painful stimulus—the first pain. They respond to mechanical and thermal threats and relay precise information about where the injury occurred. In contrast, C fibers are unmyelinated and transmit a slower, dull, lingering burning sensation—the second pain. So, the rapid, sharp pain you notice first points to A-delta fibers.

Fast, sharp pain is carried by A-delta fibers. These thinly myelinated fibers conduct signals quickly, producing the immediate, localized pain you feel right after a painful stimulus—the first pain. They respond to mechanical and thermal threats and relay precise information about where the injury occurred. In contrast, C fibers are unmyelinated and transmit a slower, dull, lingering burning sensation—the second pain. So, the rapid, sharp pain you notice first points to A-delta fibers.