Visceral Motor System - ANS Flashcards Preview

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Flashcards in Visceral Motor System - ANS Deck (11):


Sympathetic (Fight or Flight)
Parasympathetic (Rest/Digest)



Thoracolumbar (sympathetic chain, lateral horn, T1 to L2)
Energy expending system
NT = norepinephrine


Sympathetic - Presynaptic cell bodies are located...

in the interomediolateral cell column (or the lateral horn) that goes between T1 to L2 or L3


Sympathetic - Postsynapitc cell bodies...

Paravertebral ganglion - Sit beside the vertebrae, Sympathetic Chain, extends from C1 to sacrococcygeal junction
Prevertebral ganglion = AKA preaortic, surrounds origins of the main branches of the abdominal aorta


Sympathetic - White and Gray Rami Communcantes

Connection of the sympathetic chain to the spinal nerve
White = myelinated presynaptic axons (T1-L2)
Gray = unmyelinated postsynaptic axons (throughout the entire chain)


Sympathetic - Course of Presynaptic Fibers

1. Enter spnal nerve via the ventral root
2. Enter sympathetic chain via white rami comm.
3. Can cynapse immediately
4. Or can ascend/descend and synapse there
5. Can pass though the chain without synapsing and go to vessels (Splanchnic nerves go to prevertebral ganglion)


Sympathetic - Course of Postsynaptic Fibers

1. Run through the gray rami comm to enter spinal nerve
2. Head - follow branches of carotid artery
3. Splanchnic nerves follow branches of abdominal aorta
4. Visceral afferent run with symp. division of ANS in a dermatomal pattern...
T1-T4 = head and neck
T1-T7 = heart and lungs
T5-T7 = upper extremities
T2-L2 = GI system
T6-T9 = Liver and gallbladder
T5-T11 = Pancreas and spleen
T10-L2 = lower extremities



Craniosacral (feeding and digesting)
Energy conserving
NT = Acetylcholine


Parasympathetic - Sites of Presynaptic Cell Bodies

Cranial nerves 3, 7, 9, 10
Sacral segments 2-4 (keeps it off the floor)


Parasympathetic - Sites of Postsynaptic Cell Bodies

Within the wall of the organ that it innervates
Very close to the organ
Short to enable fine motor control of the GI system


Dual Sympathetic and Parasympathetic EXCEPT..

Arrector Pili Muscles
Peripheral Blood Vessels
Sweat and Suprarenal Glands
These are only sympathetic