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
Main Differences between Somatic Motor and visceral motor nerve Somatic Visceral Effectors Skeletal muscles Cardiac, smooth muscles and glands Control Voluntary Involuntary(unconsciousness (consciousness) From lower Single neuron Two neurons. center to effect Preganglionic neuron or to require Postganglionic neuron Kind of fibers One TWo: sympathetic parasympathetic Fibers Thick myelinated Preganglionic: thin myelinated postganglionic: unmyelinated Distributive form Nerve trunk Nerve plexuses Transmitter Acetylcholine Preganglionic: acetylcholine postganglionic: Ach or NE Ach-acetyIcholine. NE-nonepinephrine
7 Main Differences Between Somatic Motor and Visceral Motor Nerve Somatic Visceral Effectors Skeletal muscles Cardiac, smooth muscles and glands Control Voluntary (consciousness) Involuntary (unconsciousness ) From lower center to effector to require Single neuron Two neurons: Preganglionic neuron, Postganglionic neuron Kind of fibers One Two: sympathetic & parasympathetic Fibers Thick myelinated Preganglionic: thin myelinated postganglionic: unmyelinated Distributive form Nerve trunk Nerve plexuses Transmitter Acetylcholine Preganglionic: acetylcholine postganglionic: Ach or NE Ach-acetylcholine. NE-nonepinephrine
Neurotransmitters-Learn by yourself Somatic nervous system ACh Striated muscle Autonomic nervous system Sympathe Heart Ch <NE Sm. mus Glands ACh ACh Sweat glands ACh E NE Parasympathetic Heart <ACh ACh Sm. mus Glands Ach- acetylcholine; E-epinephrin; NE-norepinephrine
8 Neurotransmitters-Learn by yourself ACh ACh Sweat glands Striated muscle ACh Somatic nervous system Heart Sm. mus. Glands ACh ACh Parasympathetic ACh E, NE Heart Sm. mus. Glands ACh NE Autonomic nervous system Sympathetic Ach- acetylcholine; E-epinephrin; NE-norepinephrine
Sympathetic Nerve Institution Lower center Lateral horn in gray matter of T1 L3 Sympathetic trunk Perpheral Sympathetic ganglia Branches from sympathetic ganglia part Sympathetic plexus
9 Sympathetic Nerve Lower center Peripheral part Sympathetic trunk Sympathetic ganglia Branches from sympathetic ganglia Sympathetic plexus Lateral horn in gray matter of T1～ L 3 Institution
Sympathetic Part Lower center. located in intermediolateral nucleus(lateral gray horn) of spinal cord segments T1-L2 or L3 Sympathetic ganglia Paravertebral ganglia Prevertebral ganglia Transverse section of upper lumbar segment
10 Sympathetic Part Lower center: located in intermediolateral nucleus (lateral gray horn) of spinal cord segments T1~L2 or L3 Sympathetic ganglia Paravertebral ganglia Prevertebral ganglia Transverse section of upper lumbar segment