How does the duration of pain from A fibers relate to the painful stimulus?

How does the duration of pain from A fibers relate to the painful stimulus?

• A. Coincides with duration of stimulus
• B. Exceeds duration of stimulus
• C. Precedes stimulus
• D. Unrelated to stimulus duration

Answer: (D)

A-delta fibers carry fast, sharp, well-localized pain that is tightly tied to the presence of the noxious stimulus. Because these fibers conduct quickly, the pain sensation appears as soon as the stimulus is applied and ends soon after the stimulus is removed. In other words, the duration of pain from A fibers coincides with the duration of the stimulus. This contrasts with slow, dull pain carried by C fibers, which can linger after the stimulus ends due to slower conduction and longer processing. So the best understanding is that A-fiber–related pain lasts only for the time of the stimulus; it does not precede, outlast, or stay unrelated to the stimulus duration.

A-delta fibers carry fast, sharp, well-localized pain that is tightly tied to the presence of the noxious stimulus. Because these fibers conduct quickly, the pain sensation appears as soon as the stimulus is applied and ends soon after the stimulus is removed. In other words, the duration of pain from A fibers coincides with the duration of the stimulus.

This contrasts with slow, dull pain carried by C fibers, which can linger after the stimulus ends due to slower conduction and longer processing. So the best understanding is that A-fiber–related pain lasts only for the time of the stimulus; it does not precede, outlast, or stay unrelated to the stimulus duration.