C fibers terminate primarily in which laminae?

C fibers terminate primarily in which laminae?

• A. Lamina I
• B. Lamina II and III
• C. Lamina IV
• D. Lamina V

Answer: (B)

C fibers are unmyelinated, slow-conducting nociceptive fibers that carry dull, aching pain. Their central terminals in the dorsal horn are concentrated in the superficial layers, especially the substantia gelatinosa (lamina II), with substantial input extending into lamina III. This region is the main site where nociceptive information from C fibers is processed before it’s relayed onward. By contrast, A-delta fibers (fast, sharp pain) terminate more in lamina I and the outer part of lamina II, while deeper laminae (IV–VI) handle other sensory inputs. Therefore, C fibers terminate primarily in lamina II and III.

C fibers are unmyelinated, slow-conducting nociceptive fibers that carry dull, aching pain. Their central terminals in the dorsal horn are concentrated in the superficial layers, especially the substantia gelatinosa (lamina II), with substantial input extending into lamina III. This region is the main site where nociceptive information from C fibers is processed before it’s relayed onward. By contrast, A-delta fibers (fast, sharp pain) terminate more in lamina I and the outer part of lamina II, while deeper laminae (IV–VI) handle other sensory inputs. Therefore, C fibers terminate primarily in lamina II and III.