Autonomic Nervous System Flashcards
Visceral neurons innervate
organs, glands, involuntary muscle tissues (smooth and cardiac)
The autonomic NS consists of __ neurons only
VE
autonomic happens unconsciously so no sensory involved (no VA!)
2 systems of the ANS
sympathetic, parasympathetic
VE neurons are specific to the neurons of the ___
ANS
__ neurons return viscerosensory information from organs, glands, and involuntary muscles to the CNS
VA
4 rules of visceral neurons
- either VE or VA
- VE are part of the ANS
- VA are simply VA
- VE neurons form 2 pathways (pre, post)
VA and VE are part of the sympathetic and parasympathetic NS. T/F
F; only VE
VA is simply visceral neuron
preganglionic neuron is located in ___
CNS
VE/VA neurons are pre and post ganglionic
VE
postganglionic neuron is found in ___
PNS
4 examples of VE neurons found in the 2 pathways of the ANS
VE sym/pre
VE sym/post
VE para/pre
VE para/post
Sympathetic NS:
location of preganglionic neurons
(VE sym/pre)
CNS; LATERAL grey horn T1-L2 spinal cord segment
Sympathetic NS:
2 places postganglionic neurons are found
(VE sym/post)
sympathetic chain
sympathetic ganglia (abdomen)
VE sym/pre aka
Thoracolumbar outflow
sympathetic NS has __ preganglionic fibers and __ postganglionic fibers
short pre
long post
VE sym/pre
VE sym/post
which is long and short
short
long
__ __ serves as a highway for sympathetic fibers to reach areas above and below __
sympathetic chain, T1-L2
Single ganglion where sympathetic chain join together at the coccyx
ganglion impar
what type of neuron is found in ganglia of sympathetic chain?
VE sym/post (cell bodies)
Location of cell bodies:
VE sym/pre
VE sym/post
pre: lateral grey horn
post: sympathetic chan, sympathetic ganglia
Trajectory of VE sym/pre scenario 1
lateral grey horn -> ventral root -> spinal nerve -> ventral ramus -> white ramus -> sympathetic chain -> grey ramus -> (back to) spinal nerve -> dorsal/ventral ramus -> target
Where are white rami found?
only in VE sym/pre of T1-L2
white rami is in between
ventral ramus, sympathetic chain
VE sym/pre reach sympathetic chain: 4 scenarios?
1) synapse with post at sympathetic chain and target T1-L2 destinations
2) synapse with post at sympathetic chain and target above and below T1-L2
3) synapse with post at sympathetic chain, enter splanchnic nerve and target thoracic organs
4) descend, enter thoacic splanchnic nerves, and synapse VE sym/post in sympathetic ganglia (not chain)
VE sym/post fibers enter via __ –> sympathetic chain –> exit via __
white ramus, grey ramus
For scenario #3 of VE sym/post trajectory, fibers exit the sympathetic chain as __ nerve, which target 3 areas in the thorax
splanchnic (organ) nerve;
heart, respiratory tract, esophagus
Full trajectory of #3 VE sym/post trajectory
sympathetic chain -> grey ramus -> dorsal/ventral rami -> visceral plexus -> target organ
Define visceral plexus. symp/para/ or both?
network of visceral neuron fibers; almost always both
Scenario 4 of VE sym/post target organs in:
abdomen or pelvis
how is Scenario 4 of VE sympathetic trajectory different from other 3? (lower body)
3: synapse at sympathetic chain -> enter splanchic nerve -> organs of thorax + 1/3 upper abdomen
4: pass sympathetic chain -> enter thoracic splanchnic nerve -> abdomen -> synapse at pre-aortic ganglia -> visceral plexus -> target (1/3 lower abdomen, pelvis)
Trajectory of VE sympathetic trajectory to head
VE sym/PRE fibers travel to top of the sympathetic chain and synapse at the superior cervical ganglion
Adrenal glands are ONLY innervated by __ NS.
sympathetic
Adrenal glad releases __ via __ NS.
epinephrine (adrenaline)
norepinephrine
sympathetic
VE sympathetic fiber trajectory to adrenal gland
VE sym/pre fiber enter sympathetic chain -> splanchnic nerve -> synapse on cells of adrenal gland that secrete epinephrine
Locations of the VE para/pre
short or long?
in CNS: cranial nerve nuclei + sacral spinal cord
VE para/pre is very long
- CN III, VII, IX nuclei in brainstem
- CN X in brainstem
- sacral spinal cord (lower 1/3)
Location of VE para/post
short or long?
outside of the head, in the wall of the organ innervated;
VE para/post is very short
sympathetic NS aka:
parasympathetic NS aka:
Thoracolumbar outflow
Craniosacral outflow
Where does the VE para/pre fibers that innervate the organs of the thorax and 2/3 of abdomen come from?
CN X
CN X supplies __ fiber to __
VE para/pre fibers
organs of thorax and upper 2/3 of abdomen
Sacral spinal cord supplies __ fiber to __
VE para/pre fibers
lower 1/3 of abdomen and all of pelvis (pelvic splanchnic nerves)
CN X course (VE para/pre and post):
skull -> neck -> thorax -> visceral plexuses (3)
esophageal, cardiac, pulmonary plexuses
Where CN X does not reach (lower 1/3 abdomen + pelvic area), VE para/pre fibers from __ __ __ form __ __ nerves go.
sacral spinal cord,
pelvic splanchnic
Sacral outflow portion of the parasympathetic NS
Pelvic splanchnic nerves that emerge from the VE para/pre fibers
2 general categories of VA (visceral sensory) fibers
- detect sensation we are conscious of (pain, nausea)
2. those we are not aware of (pH)
VA fibers with conscious sensation travel back to __ __ (similar route to __ fibers)
spinal cord
sympathetic (DRG)
VA fibers that we are not consciously aware of travel back to __ or __ __ __ (similar route to __ fibers)
brain or sacral spinal cord
parasympathetic
Types of neurons found in DRG
SA, VA (pain sensing)
Types of nerve fibers found in VR
SE, VE sym/pre
When answering questions about the innervation of organs, __ fibers are an important part of the answer, this stands in contrast to questions about spinal nerves (!).
VA
VA - important for organs, not for spinal cords!
