Flashcards in Sievert ANS Deck (45):
Parasym. associates with which vertebrae and cranial nerves?
S2-4, brainstem nuclei associated with Cranial nerves 3,7,9,10
Symp. associates with which vertebrae?
T1-L2, Lateral horn of grey matter
Explain the synaptic connections in the Parasym.
1. between first (preganglionic) (CNS) and second (postganglionic) neurons
2. between postganglionic neuron (Paravertebral/chain, pre vertebral/ aorta) and effector cell
The adrenal medulla only gets (blank)
(Blank) fibers can talk to the enteric nervous system cell bodies
All (Blank) are cholinergic (both pre and post). (Blank) pre are cholinergic, post are adrenolergic. Except for skin. Skin is cholinergic.
T or F: There are synapses in all autonomic ganglion
T or F: sensory nerves have a synapse
T or F: there are synapses in the DRG
In divergence, if you stimulate preganglionic will have a (blank) effect. If you have convergence, will have a much more (Blank) effect.
What are the possible routes for an afferent axon?
Their axon once going back to spinal cord can go locally for reflexes, up to higher centers for conscious awareness, or they could go up for regulating a pattern generator or regulating cardiovascular responses or something that you're not privy to.
Where are the cell bodies for the autonomic system?
Cell bodies of autonomics (visceromotor) are in the lateral horn (intermediate gray) of very specific levels T1-L2 for sympathetics and S2-4 for para.
Where are the cell bodies for the somatomotor fibers?
Cell bodies of somatomotor fibers are in the ventral horn
(Blank) nerves go to the pelvic viscera and also to the abdominal cavity for descending colon.
preganglionic has to leave spinal nerve, otherwise it would go to (blank)
In regards to the parasymp. and as far as the GI tract is concerned, second neuron is also part of the (Blank)
enteric nervous system
The parasymp. only innervates the...
Parasympathetic only innervates viscera in body cavities, glands in the head, the eye and erectile tissues. Do not travel on spinal nerves.
Describe path of sympathetic fibers.
1) originate in T1-L2, intermediate gray (lateral horn)
2) go through the ventral root, can synapse in two places.
3) In the sympathetic chain, which is paravertebral because they go down right alongside vertebral column, or they can synapse at prevertebral/preaortic ganglia.
4) Anything above diaphragm will synapse in chain via communicating rami before going to target. Anything under diaphragm goes to prevertebral ganglia to synapse, then goes to target (don't synapse in chain).
The sympathetic nerve itself doesn't have to come out below the diaphragm, the important thing is that the (blank) is below the diaphragm.
All body wall (blank) synapse in the chain at or near the spinal nerve where they will ultimately distribute to targets. So it may go down the chain to the ganglion where it will synapse and go right out to spinal nerve.
White rami are also known as...
preganglionic communicating, only found in T1-L2
Grey rami are also known as...
postganglionic communicating ramus; found in all vert. and return signal to spinal nerve
two names for thoracic splanchnics
1) Plain old thoracic splanchnics which you'll see target viscera in the thorax
2) thoracic splanchnics coming off that go below the diaphragm: greater/lesser/least thoracic splanchnic. Would not synapse in the chain.
T or F: sympathetics can travel on spinal nerves
true. To get out of the cord, and to travel to body wall targets, splanchnic nerves (to get to viscera), or blood vessels (as an end point in their destination to viscera or to the head)
T or F: Sympathetic chain runs the entire length of the vertebral column.
Sympathetics to the head come from (blank) and travel up the chain aspreganglionic fibers. They synapse in the highest ganglion (superior cervical) and travel to structures in the head on blood vessels ( or cranial nerves).
How do sympathetics get on spinal nerves above T1/below L2?
Because there are no preganglionic fibers above T1/below L2, spinal nerves at these levesl must get their sympathetics from fibers that go up or down the chain, and synapse before leaving as a gray communicating ramus. Body wall outside of T1-L2 – only have gray rami, so have to connect to those spinal nerves with preganglionics from levels in T1-L2 that ascend/descent. Doesn't synapse until it gets to the spinal nerve near where it wants to target.
Is there ever an instance where there is presynaptic neuron on grey ramus?
NO. Greys are only post gang.
Most of the sympathetics to the thorax come from the (blank) after synapsing.
inferior cervical chain ganglion
Guess where most of the sympathetics to the chest go? Are they synapsed?
To the cardiopulmonary plexus.
Yes, above the diaphragm.
Any fiber leaving chain going posterolaterally is a (blank)
The nerves that give rise to these abdominal sympathetics are the (blank).
greater, lesser, least thoracic splanchnic nerves. Come from successively lower levels of sympathetic chain. Remember these do not synapse in the chain. They are targeting structures BELOW the diaphragm. Alongside vertebral body in anteromedial position
After passing through the diaphragm, where do the symp. pre gang fibers synapse?
Sympathetics in abdomen come directly off chain in the region of the lumbar vertebra and synapse in other preaortic ganglia.
lumbar splanchnics. Does not synapse in chain.
Most sympathetics in pelvis – come from abdominal cavity and come off in the (blank) region. Describe their path.
2)Come off chain as lumbar splanchnic, pregnaglionic still, get into plexus, then travel down on the superiror hypogastric plexus and then down to the left and right hypogastric nerves. (once out as lumbar splanchnics, still preganglionic. can either synapse up in lumbar region and go down, or go down to pelvic region and then synapse.)
Sympathetics to the pelvis usually synapse in the (blank), but there are lots of places where they could synapse.
inferior hypogastric plexus
Cells in the adrenal medulla are basically (Blank) neurons.
Where do the post gang cells of the adrenal medulla finally synapse? What is released?
adrenal medulla chromatin cells (not in the celiac ganglia), causing the release of epinephrine/norepniephrine
Visceral afferents traveling on (blank) mostly cause reflex activation or can give you a general feeling of something being wrong, but some can travel w/ (blank).
where would the cell bodies be for these visceral afferents?
How do visceral afferents travel?
1) traveling back on splanchnic nerve will go into sympathetic chain
2) back to spinal nerve through communicating ramus
3) through dorsal root to DRG.
Afferents carrying pain going with (Blank) is generally more localizable than pain carried by (blank).
pain from an organ is felt in a different area of the body
Why does referred pain exist?
don't have room for all the cells that would be necessary to handle an afferent response that you don't feel all the time.
Don't want there to be another whole neuron just for this unused receptor, so it synapses on the same cell body as before.