Which type of nerve fiber transmits deep somatic pain?

Which type of nerve fiber transmits deep somatic pain?

• A. Slow fibers
• B. Fast fibers
• C. Medium fibers
• D. Ultra-fast fibers

Answer: (A)

Deep somatic pain is carried by slow, unmyelinated fibers (C fibers). These fibers conduct signals slowly, around 0.5–2 m/s, and produce a dull, aching, poorly localized sensation that can linger. In contrast, fast, sharp pain from superficial tissues is transmitted by myelinated A-delta fibers, which conduct more quickly and give a well-localized, pricking sensation. Deep structures like muscles and joints tend to produce diffuse, persistent pain, so the slow C fibers are the primary carriers.

Deep somatic pain is carried by slow, unmyelinated fibers (C fibers). These fibers conduct signals slowly, around 0.5–2 m/s, and produce a dull, aching, poorly localized sensation that can linger. In contrast, fast, sharp pain from superficial tissues is transmitted by myelinated A-delta fibers, which conduct more quickly and give a well-localized, pricking sensation. Deep structures like muscles and joints tend to produce diffuse, persistent pain, so the slow C fibers are the primary carriers.