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autonomic nervous system
- regulates activity of smooth muscle, cardiac, and muscle glands
- 2 neurons and a ganglion
- 2 neurotransmitters: Ach and Ne
- 2 divisions: sympathetic and parasympathetic
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ganglion
- mass of nervous tissue that contains cell bodies
- located outside of CNS
-
preganglionic neuron
neuron before the ganglion
-
postganglionic neuron
neuron after the ganglion
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sympathetic nervous system
- emergency - fight or flight
- handles situations out of homeostasis
- rapid breathing, dry mouth, increased HR, bladder contraction, increased BP, decreased digestion, dilated pupils
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thoracolumbar outflow
- origin of SNS
- between T1 and L2 vertebrae
- ganglion close to CNS
-
prevertebral ganglion
ganglion in front of the spinal cord
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paravertebral ganglion
ganglion on sides of spinal cord
-
preganglionic axon in SNS
- short, thick, myelinated
- releases Ach
- many collaterals (makes SNS effects widespread)
-
postganglionic axon in SNS
- long, thin, unmyelinated
- releases Ne
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parasympathetic nervous system
- housekeeping - feed and breed
- opposite of SNS effects (normals)
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cranialsacral outflow
- origin of PSNS
- cranial nerves 3, 7, 9, 10, and S2-S4 vertebrae
- 90% originate at vagus nerve (X)
-
terminal ganglion
- PSNS ganglion
- always near effector
-
preganglionic axon in PSNS
- long, thick, myelinated
- releases Ach
-
postganglionic axon in PSNS
- short, thin, unmyelinated
- releases Ach
-
cholinergic fibers
- fibers that release Ach
- short lived effects - deactivated by Acetylcholinesterase
-
adrenergic fibers
- fibers that release Ne
- long lasting effects - Ne enters blood and takes long to be absorbed
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