BIOM20002 Lecture Notes - Lecture 3: Grey Matter, Enteric Nervous System, Preganglionic Nerve Fibers
Unconscious homeostatic control of the body physiology. An effector/output system
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Neurons from T1 to L3 spinal segments
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Come out of ventral root, joins to segmental nerves, target eyes, heart, gut etc.
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Sympathetic
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Only involves 3 sacral and cranial segments
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Tend to innervate the same structures
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Parasympathetic
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2 divisions which are anatomically and physiologically distinct
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Sometimes they are opposing. Sometimes they are not
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+ contributes to it
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- inhibits it
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Contribution of autonomic NS to different body parts
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The autonomic nervous system
3 Nervous system 2
Monday, July 28, 2014
10:45 AM
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Synapses in periphery are good drug targets (no blood brain barrier)
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Sympathetic: fight or flight. Innervates heart, pupils, adrenal gland, redistribution of blood
flow (to muscles rather than digestion)
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Parasympathetic: rest and digest. Optimizes physiological processes. Craniosacral outflow to
heart (slows it down)
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Paraspinal/paravertebral ganglia (sympathetic chain): adjacent/parallel to the spinal cord; a
chain formed from fused ganglia swellings. Part of the sympathetic output and contains
neurons which relay information from CNS to the periphery.
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Sympathetic (thoracolumbar) outflow
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Document Summary
2 divisions which are anatomically and physiologically distinct. Come out of ventral root, joins to segmental nerves, target eyes, heart, gut etc. Contribution of autonomic ns to different body parts. Synapses in periphery are good drug targets (no blood brain barrier) Innervates heart, pupils, adrenal gland, redistribution of blood flow (to muscles rather than digestion) Paraspinal/paravertebral ganglia (sympathetic chain): adjacent/parallel to the spinal cord; a chain formed from fused ganglia swellings. Part of the sympathetic output and contains neurons which relay information from cns to the periphery. Autonomic neurons originate in the middle of the spinal cord - the lateral horns of the grey matter. Preganglionic neuron: the first neuron merging from the lateral horn. Preganglionic neuron goes out ventral root --> spinal nerve --> white connecting ramus --> synapses with postganglionic neuron in the sympathetic chain --> postganglionic neuron goes out gray communicating ramus --> target.
