Autonomic Nervous System Flashcards
T/F: All postganglionic nerve fibers are unmyelinated?
True
T/F: Acetylcholine is used as a neurotransmitter ONLY in the parasympathetic nervous system?
False. ACh is used at the first synapse of sympathtic neurons. NE is then used at the 2nd synapse of the sympathetic neurons, while ACh is used entirely throughout the parasympathetic pathway.
In what vertebral segments can you expect to find sympathetic preganglionic fibers?
T1-L2/3
Think of the effects of Sympathetics and Parasympathetics on the cardiorespiratory system. Where are the preganglionic neurons located for the following: bronchial muscles & lung, heart rate/output, arteries (muscles), arteries (skin), and arteries (viscera)? Check yourself with this table.
What are the effects on the GI tract and the GU tract in response to sympathetics and parasympathetics?
(try to fill in the chart)
Dr. P taught that one way to remember innervation associated with erection and ejaculation.
point (erection): parasympathetic
shoot (ejaculation): sympathetic
Now think about the head.
Here are the answers:
The parasympathetic fibers that hitch a ride with CN III are going to what targets?
pupil sphincter
ciliary muscle
accomodation reflex
(ciliary ganglion)
The parasympathetic fibers hitching a ride with CN VII are going to what target(s)?
lacrimal and nasal glands (ptergyopalatine ganglion)
submandibular and sublingual glands (submandibular ganglion)
The parasympathetic fibers running with CN IX are going to what target(s)?
parotid gland (otic ganglion)
The parasympathetics fibers traveling with CN X are going to what target(s)?
heart
bronchi
gastrointestinal tract
(I believe all three can be classified under dorsal motor nucleus of Vagus)
Where would you expect to see the Edinger-Westphal nucleus? What is the signficance of this structure?
nucleus is located in the midbrain;
it is the location for the ciliary ganglion for pupillary constrictor muscle fibers and for the ciliary muscle (accomodation)
Where is the superior salivatory nucleus located?
tegmentum of pons
Where is the inferior salivatory nucleus located?
medulla
Where is the dorsal motor nucleus of Vagus located?
medulla
Other than the dorsal motor nucleus of the vagus, what other parasympathetic nucleus is associated with CN X?
nucleus ambiguus
(parasympathetic preganglionic fibers that serve the heart)
T/F:
Parasympathetic, preganglionic nerve cell bodies are found exclusively within the brainstem.
False
nerve cell bodies associated with cranial nerves are found exclusively in the brainstem, however there are also preganglionic nerve cell bodies in the lateral horn of spinal cord between S2-4 (which goes to pelvic splanchnic nerves)
What are the four things that preganglionic sympathetic fibers do after leaving the ventral root?
- some fibers synapse in nearest ganglion
- some fibers ascend chain, synapse in SCG or MCG
- some descend, synapse in lumbar/sacral ganglia
- some traverse chain, emerge as splachnic nerves
What are the ways that sympathetic postganglionic fibers reach the head?
cervical ganglia & carotid plexus
Loss of sympathetic innervation to the face is known as what syndrome?
Horner syndrome
These are some symptoms of Horner Syndrome. Define them:
Ptosis
Miosis
Endopthalmos
Anhydrosis
Heterochromia
Ptosis: eyelid droop (superior tarsal muscle)
Miosis: small pupil
Endopthalmos: apparent sunken eye
Anhydrosis: dry skin
Heterochromia: different colored eyes (occurs if condition sets in before age 2)
Why does referred pain occur?
visceral structure is innervated by same cord level as surface structure
What does the enteric nervous system innervate?
intestinal tract
pancreas & gall bladder
What is (are) the neural plexus(es) of the intestinal tract?
myenteric plexus (Auerbach)
submucous plexus (Meissner)
What is the function of the enteric nervous system?
provides primary control of motility and secretion
