A-delta fiber is defined as which of the following?

A-delta fiber is defined as which of the following?

• A. A peripheral nerve that carries nociceptive stimuli resulting in acute pain; larger and faster-acting than C fibers.
• B. A nerve fiber that carries only touch.
• C. The smallest neuron.
• D. A fiber that conducts slow impulses.

Answer: (A)

Nociceptive fast-conducting fibers are myelinated, medium-diameter nerve fibers that transmit fast, sharp, well-localized pain. A-delta fibers fit this description because they carry nociceptive signals that produce acute pain and do so more quickly than other pain fibers, thanks to their myelination and larger diameter. In pain pathways, this fast transmission is what you feel as the immediate, stabbing sensation right after tissue injury—the first pain. Compared with C fibers, which are unmeyelinated and conduct more slowly to produce dull, lingering pain, A-delta fibers are larger and faster, which is why they’re described as carrying acute nociceptive stimuli with quicker onset. They aren’t limited to touch, since touch is primarily carried by other fibers (like A-beta); they aren’t the smallest neurons, and they don’t conduct slow impulses.

Nociceptive fast-conducting fibers are myelinated, medium-diameter nerve fibers that transmit fast, sharp, well-localized pain. A-delta fibers fit this description because they carry nociceptive signals that produce acute pain and do so more quickly than other pain fibers, thanks to their myelination and larger diameter. In pain pathways, this fast transmission is what you feel as the immediate, stabbing sensation right after tissue injury—the first pain. Compared with C fibers, which are unmeyelinated and conduct more slowly to produce dull, lingering pain, A-delta fibers are larger and faster, which is why they’re described as carrying acute nociceptive stimuli with quicker onset. They aren’t limited to touch, since touch is primarily carried by other fibers (like A-beta); they aren’t the smallest neurons, and they don’t conduct slow impulses.