Comparison of somatic visceral efferent pathway Somatic efferent innervation acetylcholine ACh Somatic effectors Autonomic efferent innervation Acetylcholine Norepinephrine ACh ACh or NE Visceral effectors smooth muscle [postganglionic fiber glands Autonomic acetylcholine ganglion FIGURE 16.2 Comparison of Somatic and Autonomic Efferent Pathways. The entire distance from CNS to effector is spanned by one neuron in the somatic syste nd two neurons in the autonomic system. Only acetylcholine(ACh)is employed as a neurotransmitter by the somatic neuron and the autonomic preganglionic neuron, but autonomic postganglionic neurons can employ either ACh or norepinephrine(NE)6 Comparison of somatic & visceral efferent pathway acetylcholine acetylcholine Acetylcholine Norepinephrine