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Flashcards in Autonomic System Deck (26):

Describe the Autonomic system.

Controls automatic regulation of visceral organs and tissues
critical to lung function


What are the divisions of the Autonomic system?

Sympathetic (relaxes smooth muscles to dilate airways)
Parasympathetic (secretes mucus and other fluids)


Where does the pre-ganglionic cell bodies occur within the autonomic system?

Within the CNS


Where does pre-ganglionic nerve fibers occur?

they extend outside the CNS into the PNS.
they are myenlinated


With what does the pre-ganglionic fibers synapse with?

post ganglionic cell bodies in the PNS who's fibers travel to the target organ


What is the difference between afferent and efferent neurons?

Afferent - one neuron concept, sends sensory info to CNS
efferent- two neuron concept sends, motor info from CNS to target organ


What are pre-ganglionic nerves

nerves who, cell body are within the CNS but the their axons extend outside the the CNS into the peripheral ganglion


Where does the cell bodies of sympathetic network originate?

spinal cord (lateral horn) T1-L4


where does the preganglonic nerve fibers extend to of the sympathetic system?

Myenlinated fibers to a ganglion laterally. The transfer goes to a post ganglionic cell and fibers (unmyenlinated) to target organ.


Where does the Efferent fibers extend from in the sympathetic nervous system?

extend from anterior horn, out of the ventral root and enter the sympathetic ganglion via the white ramus communicans. (myenlinated). They synapse in the sympathetic chain. Post ganglonic fibers leave via gray ramus.


Where does the postganglionic bodies distribute their signal?

via the gray ramus communicans


Where does the axons of the postganglionic fibers travel of the sympathetic system?

From gray ramus to the ventral or dorsal rami


What is the sympathetic chain ganglia (paravertebral sympathetic trunk)?

Connection between sympathetic ganglia superiorly and inferiorly. allows pre ganglionic fibers to travel inferior or superior to different ganglionic levels


What are the paths of pre-ganglionic fibers via the sympathetic chain ganglia?

1)Ascend- synapse with higher post-ganglion nerve
2)descend- synapse with lower post-gang nerve
3)Stay on same level
4) dont synapse, travel to meet with splanchnic nerve to reach a pre-vertbral level


Where do cervical sympathetics receive its signal?

pre-ganglionics T1-T3


Where do lumbar sympathetics receive its signal from?

pre-ganglionics T11-L3


Where do the sympathetic s for heart and lung originate?

T1-T5, synapse in chain, post-gang. do not exit gray rami. they go straight to the organ


Where do some pre-ganglionic axons T5 and below (for the abdomen) synapse and exit?

some pass through the chain into the splanchnic nerve and synapse in pre-aortic ganglia to function in the abdomen


Where do the Greater splanchnic and lesser splanchnic receives its signal?

Greater - T5-T9
lesser - T10 & T11


What are the primary abdominal ganglia and which nerve from which it receive its signal?

Celiac ganglion - Greater splanchnic
Aorticerenal - lesser splanchnic
Superior Mesentric ganglion -Greater and lesser splanchnic
Inferior Mesenteric ganglion - Lumbar splanchnic


Where do Parasympathetic pre-ganglionic axons arise, travel and synapse?

arise - in brain stem (medulla oblongata)
travel - Vagus nerve
Synapse- ganglia in target organ (postganglia found entirely in target organ, the fiber of the post ganglionic fibers or long and short)


How do the sympathetic and para-sympathetic work to control heart and lung?

Sym - (T1-T5) increase heart rate/bronchodialation
para - (Vagus)decrease heart/increase mucous production


What are the path of Afferent neurons?

they follow motor neurons, but they ar not motor neurons they are sensory neurons ( not part of the ANS)


What is the job of afferent neurons?

Visceral sensory - relaying pressure, pH conditions
signaling pain


What is the pathway for para. Afferent pathways?

Vagus (Thoracic, foregut, midgut; alters herat and respiratory rates.
sacral outflow - hindgut and pelvic viscera

80-90% of Vagus nerve axons are afferent


What is the path of the visceral pain afferents?

Referred pain symptom of visceral malfunction
signal follows sympathetics back to chain ganglia, through white rami, into spinal nerves.
in dorsal horn, visceral pain afferents synapse with axons that detect somatic pain and transfer signal to the somatic pain system