Which fiber carries nociceptive signals associated with acute pain and is larger and faster-acting than C fibers?

Which fiber carries nociceptive signals associated with acute pain and is larger and faster-acting than C fibers?

• A. A-delta fiber
• B. A-beta fiber
• C. C fiber
• D. B fiber

Answer: (A)

Acute pain signals are carried by fast, myelinated fibers known as A-delta fibers. Their larger diameter and myelination let them conduct impulses quickly, producing the immediate, sharp, well‑localized pain you feel right after an injury. This contrasts with C fibers, which are unmyelinated and slower, carrying a dull, lingering pain that follows the initial sensation. A-beta fibers handle non-nociceptive touch and proprioception, not the sharp pain signal, and B fibers are autonomic and not primary carriers of nociceptive pain. So the fiber responsible for the rapid, acute pain signal is the A-delta fiber.

Acute pain signals are carried by fast, myelinated fibers known as A-delta fibers. Their larger diameter and myelination let them conduct impulses quickly, producing the immediate, sharp, well‑localized pain you feel right after an injury. This contrasts with C fibers, which are unmyelinated and slower, carrying a dull, lingering pain that follows the initial sensation. A-beta fibers handle non-nociceptive touch and proprioception, not the sharp pain signal, and B fibers are autonomic and not primary carriers of nociceptive pain. So the fiber responsible for the rapid, acute pain signal is the A-delta fiber.