Group B Nerve fibers are situated in:: (A) Muscle spindles, (B) Fibers carrying pain sensation, (C) Preganglionic autonomic fibers, (D) Post ganglionic autonomic fibers.
Answer is C. Ans. is 'c' is Preganglionic autonomic fibres Nerve fiber types in mammalian nerve:Fiber Type AFunctionFiber Diameter (mm)Conduction Velocity (m/s)alphaProprioception; somatic motor*12-20(Max.)* 70-120betaTouch, pressure*5-1230-70gammaMotor to muscle spindles*3-615-30deltaPain, cold, touch*2-512-30BPreganglionic autonomic*<33-15C Dorsal rootPain, temperature, some mechanoreceptor, reflex responses0.4-1.20.5-2Sympathetic*Postganglionic sympathetic0.3-1.30.7-2.3* A and B fibres are myelinated; C fibres are unmyelinated.