CN X Flashcards
What is the name of CN X?
Vagus nerve
What CN is the vagus nerve?
CN X
How is the vagus nerve classified?
mixed cranial nerve
What kind of information is carried in the vagus nerve?
motor, parasympathetic, and sensory info
some taste
Where does the taste information come from?
the epiglottal region
What makes the vagus nerve special?
it is the LONGEST cranial nerve
The vagus is also considered……?
the most important parasympathetic nerve
Where are the cell bodies of the motor fibers located?
nucleus ambiguus
Where does the nucleus ambiguus receive information from?
both the cerebral hemispheres
Where do the preganglionic parasympathetic fibers of the vagus nerve arise from (cell body location)?
posterior (dorsal) nucleus of the vagus
What information is indirectly received in the posterior (dorsal) nucleus of the vagus?
hypothalamus and carotid sinus
What are the nuclei of termination for the vagus nerve?
1) spinal nucleus of CN V
2) nucleus of the solitary tract
Where does the somatic sensory information of the vagus terminate?
spinal nucleus of the trigeminal
Where does taste and viscerosensory info from the vagus terminate?
nucleus of the solitary tract
What are the two peripheral ganglia associated with the vagus nerve?
superior and inferior ganglia
NOT THE SAME AS THE CN IX ONES
What is another name for the superior ganglion of the vagus?
jugular ganglion**
What is another name for the inferior ganglion of the vagus?
nodose ganglion**
What information of the vagus doesn’t have a nuclei of termination?
no parasympathetic ganglion
Where are the cell bodies of the somatic sensory info located?
superior (jugular) ganglion
Where is the somatic sensory info of the vagus from?
DURA (INFRATENTORIAL/POSTERIOR FOSSA)
auricle, external auditory canal, lateral tympanic membrane, mucosa of the oropharynx and laryngopharynx
What is the nuclei of termination for the somatic sensory info of the vagus?
spinal nucleus of the trigeminal nerve (CN V)
Where is the spinal nucleus of the trigeminal nerve found?
in the cord and inferior to the MO to C5 level
What else travels to the spinal nucleus of the trigeminal nerve?
pain
Where are the cell bodies for the vagus taste info found?
inferior (nodose) ganglion
Where does the vagus taste info terminate?
superior part of the nucleus of the solitary tract
Where are the visceral sensory info of the vagus cell bodies found?
inferior (nodose) ganglion
What is the nucleus of termination of the visceral sensory info of the vagus?
inferior part of the nucleus for the solitary tract
What visceral sensory info is carried in the vagus?
larynx, laryngopharynx, viscera in the thoracic and abdominal cavities, pressure receptors in the aortic acrch and chemoreceptors in the paraaortic body
What is the apparent origin of the vagus nerve?
lateral aspect of the medulla oblongota as a series of rootlets (just inferior to CN IX)
The rootlets combine into a trunk and give off a branch before exiting the jugular foramen…. what is the branch?
meningeal branch
What does the meningeal branch supply?
dura of the posterior INFRATENTORIAL cranial fossa
What is the meningeal branch given off before?
jugular foramen
What part of the jugular foramen do the vagus and accessory exit?
anterior to septum
What part of the jugular foramen does the glossopharyngeal nerve exit?
posterior to the septum
What do the vagus and accessory nerves share?
menigeal sheath (arachnoid and dura)
Where is the superior (jugular) ganglion found?
in the jugular foramen
Where is the inferior (nodose) ganglion found?
just out side the jugular foramen
Which vagal ganglion is larger and more cylindrically shaped?
the inferior (nodose) ganglion
What branch is given off at the superior (jugular) ganglion?
auricular branch
What does the auricular branch supply?
external auditory meatus
sensory: meatus and small portion of the auricle
What is the course of the auricular branch take?
through the mastoid canaliculus and tympanomastoid fissure to reach external auditory meatus
After the vagus exits the jugular foramen what does it travel in?
in the carotid sheath with the internal carotid artery and internal jugular vein
What does the vagus nerve travel with inferior to the carotid bifurcation?
between the internal jugular vein and common carotid artery
What does the common carotid artery give off?
inferior carotid artery
Where is the pharyngeal branch given off?
given off in the neck
What level is the pharyngeal branch of the vagus given off at?
at the level of the inferior ganglion
What will the pharyngeal branches of the vagus nerve combine with?
fibers from the glossopharyngeal nerve and sympathetic fibers from the sympathetic trunk forming the pharyngeal plexus
Vagal motor fibers of the pharyngeal plexus supply what muscles?
pharyngeal constrictor muscles, levator veli palatine muscle of the soft palate
Where are the vagal branches to the carotid artery given off?
at the inferior ganglion
What kind of fibers are carried in the branches to the carotid artery?
viscerosensory fibers
What in the nuclei of termination for the vagal branches to the carotid artery?
inferior part of the nucleus of the solitary tract
What do the viscerosensory fibers of the vagal branches to the carotid artery carry information from?
chemoreceptors in the carotid body
Where is the superior laryngeal nerve given off at?
just inferior to the inferior ganglion
What does the superior laryngeal nerve divide into?
internal and external laryngeal nerve
What does the external laryngeal nerve supply?
brachiomotor fibers to the cricothyroid muscle
What does the internal laryngeal nerve supply?
sensory info from the laryngeal mucosa as far inferior as the vocal folds
Where do the internal laryngeal nerve fibers synapse?
the spinal nucleus of the trigeminal
What muscle doesn’t the recurrent laryngeal supply?
cricothyroid
What muscles does the recurrent laryngeal nerve supply?
all muscles of the larynx except the cricothyroid
What sensory information does the recurrent meningeal nerve of the vagus carry?
larynx inferior to the vocal folds
How does the left recurrent laryngeal nerve travel?
comes off vagus after the vagus passes INFRONT of the aortic arch, passes UNDER the aortic arch, ascends becoming the inferior laryngeal nerve
What does the inferior laryngeal nerve supply?
laryngeal muscle
What is the inferior laryngeal nerve a continuation of?
left recurrent laryngeal nerve
How does the right recurrent laryngeal nerve travel?
passes posteriorly UNDER the the subclavian artery, ascending similar to left
What direction do the right and left recurrent laryngeal travel?
ascend
What kind of information does the superior and inferior cervical cardiac branches carry?
parasympathetic info to cardiac plexus
How do the superior cervical cardiac plexus travel?
with the great vessels (ascending aorta and superior vena cava) to cardiac plexus
What are the inferior cervical cardiac branches given off by?
recurrent laryngeal nerves traveling to the cardiac plexus
One branch will carry viscerosensory information concerning pressure from where?
wall of the aorta
When is the viscerosensory branch to the wall of the aorta stimulated?
when the aortic pressure becomes too high
How does the vagus nerve enter the thorax?
posterior to the root of the ipsilateral lung, contributing to the pulmonary plexus
What does the posterior pulmonary plexus carry?
larger, sympathetic info T2-5 or 6
What does the anterior pulmonary plexus carry?
cervical sympathetic ganglia
How does the right vagus nerve pass?
posterior, behind the esophagus
How does the left vagus nerve pass?
anterior, in front of the esophagus
What do the right and left vagus nerve in the thorax contribute to?
esophageal plexus
How does the right vagal nerve enter the abdominal cavity?
through the esophageal opening, becoming the posterior vagal trunk
What does the posterior vagal trunk send branches to?
the posterior stomach
What does the posterior vagal trunk end in?
large celiac branch
What does the celiac branch send branches to?
duodenum, liver, kidneys, SI, proximal 2/3 of the LI
The celiac branch of the vagus sends fibers what plexuses that supply the abdominal organs?
celiac, superior mesenteric, and renal plexuses
What does the left vagus nerve become after entering the abdominal cavity?
anterior vagal trunk
What organs does the anterior vagal trunk supply?
stomach, liver, pancreas, and superior part of the duodenum
What are some clinical considerations associated with the vagus nerve?
bilateral transection
lesions within the vault or close to the skull
damage to the recurrent laryngeal nerve
