Arrange the following sequentially in the descending order of nerve impulse transmission velocity: A. C B. Aa C. B D. Ad: (A) A-D-C-B, (B) B-D-C-A, (C) A-C-D-B, (D) C-A-B-D
Answer is B. Erlanger Gasser's Classificaiton of sensory and motor neurons Fiber type Functions Fiber diameter (um) Conduction velocity (m/sec) Aa Proprioception, somatic motor 12-20 70-120 Ab Touch, pressure 5-12 30-70 Ag Motor to muscle spindles 3-6 15-30 Ad Pain, temperature 2-5 12-30 B Preganglionic autonomic <3 3-15 C (dorsal root) Pain, temperature 0.4-1.2 0.5-2 C (Sympathetic) Postganglionic sympathetic 0.3-1.3 0.7-2.3