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 fibers
Type B
Type C (pain)
Type C (postganglionic)
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
General physiology