<prompt> A person wakes up with pain, paraesthesia, tingling in the arms. He had slept with arm below the head. Which fibers are involved?Type A fibersType BType C painType C postganglionic  <response>: In the general classification, the fibers are divided into types A and C, and the type A fibers are fuher subdivided into a, b, g, and d fibers. Alternative classification:Group Ia. Fibers from the annulospiral endings of muscle spindles about 17 microns in diameter on average; these fibers are a-type A fibers in the general classification.Group Ib. Fibers from the Golgi tendon organs about 16 micrometers in diameter on average; these fibers also are a-type A fibers.Group II. Fibers from most discrete cutaneous tactile receptors and from the flower-spray endings of the muscle spindles about 8 micrometers in diameter on average; these fibers are b- and g-type A fibers in the general classification.Group III. Fibers carrying temperature, crude touch, and pricking pain sensations about 3 micrometers in diameter on average; they are d-type A fibers in the general classification.Group IV. Unmyelinated fibers carrying pain, itch, temperature, and crude touch sensations 0.5 to 2 micrometers in diameter; they are type C fibers in the general classification.Ref: Guyton; 13th edition; Chapter 47; Sensory Receptors, Neuronal Circuits for Processing Information 