Which type of nerve fiber is responsible for sharp pain and temperature sensation?

Which type of nerve fiber is responsible for sharp pain and temperature sensation?

• A. A-alpha
• B. A-gamma
• C. A-delta
• D. C

Answer: (C)

Signals for sharp, fast pain and cold temperature are carried by thinly myelinated A-delta fibers. Their quicker conduction compared with unmyelinated fibers lets you feel a precise, immediate, well-localized pain right after a noxious stimulus, such as a quick prick, and they contribute to sensing cold. A-delta fibers respond to noxious mechanical and thermal inputs and rapidly relay that information to the spinal cord for swift withdrawal reflexes. In contrast, other fibers have different roles: A-alpha fibers are large, myelinated fibers mainly for motor control and proprioception; A-beta fibers convey light touch; A-gamma fibers are motor fibers to the muscle spindles; and C fibers are unmyelinated, conducting more slowly to transmit dull, burning pain and warmth.

Signals for sharp, fast pain and cold temperature are carried by thinly myelinated A-delta fibers. Their quicker conduction compared with unmyelinated fibers lets you feel a precise, immediate, well-localized pain right after a noxious stimulus, such as a quick prick, and they contribute to sensing cold. A-delta fibers respond to noxious mechanical and thermal inputs and rapidly relay that information to the spinal cord for swift withdrawal reflexes.

In contrast, other fibers have different roles: A-alpha fibers are large, myelinated fibers mainly for motor control and proprioception; A-beta fibers convey light touch; A-gamma fibers are motor fibers to the muscle spindles; and C fibers are unmyelinated, conducting more slowly to transmit dull, burning pain and warmth.