Exam 2 CN X Flashcards
Is vagus a motor or sensory nerve?
It is mixed!
What type of fibers does the vagus nerve carry
Motor, parasympathetic, and sensory information
Where does the vagus carry some taste information from
The epiglottal region
What 2 things make the vagus nerve so special
- it is the longest cranial nerve
- it is the most important parasympathetic nerve
Where are the motor fibers cell bodies that are carried in the vagus
In the nucleus ambiguus
Where does the nucleus ambiguus receive information from
Both cerebral hemispheres
Where do preganglionic parasympathetic fibers arise from in the vagus
The posterior (dorsal) nucleus of the vagus
Where do the preganglionic parasympathetic fibers receive info from?
Indirectly from hypothalamus and carotid sinus
What terminates in the spinal nucleus of CN V when talking about the vagus
Somatic sensory
What information terminates in the nucleus of the solitary tract
Taste and viscerosensory
What two peripheral ganglia are associated with the vagus nerve and what are their alternate names?
Superior (jugular) and inferior (nodose) ganglions . Not the same as in CN IX
Where are the cell bodies located for neurons carrying somatic sensory information
Superior ganglion or jugular ganglion
How is taste from the epiglottis carried in vagus
Carried to the superior portion of nucleus of the solitary tract by neurons located in the inferior ganglion
How is visceral sensory information carried in the vagus
It is carried to the inferior part of the nucleus for the solitary tract by neurons located in the inferior ganglion
Where does the vagus nerve carry visceral sensory information from?
Larynx, laryngopharynx, viscera in thoracic/abdominal cavities, pressure receptors in aortic arch, chemoreceptors in para-aortic body
Where does the vagus nerve emerge from as a series of rootlets
The lateral aspect of medulla oblongata (A.O.)
What branch of vagus supplies the infratentorial dura (posterior cranial fossa)?
Meningeal branch
How does the vagus exit the skull?
Through the jugular foramen
How is the jugular foramen compartmentalized
By a fibrous septum. C.N. X and XI travel anterior to the septum. C.N. IX travels posterior to the septum
What two CN share a meningeal sheath (arachnoid and dura)
CN X and XI
Which ganglion is located in the jugular foramen
The superior ganglion
Where is the inferior ganglion located
Just inferior to jugular foramen
What branch carries sensory information from the meatus and small portion of the auricle
The auricular branch
What is the course of the auricular branch
Through mastoid canaliculus and tympanomastoid fissure to reach external auditory meatus
After exiting the jugular foramen and moving inferiorly what does the vagus nerve travel within
Carotid sheath
Where is the carotid sheath located
Between internal carotid artery and internal jugular vein
Where does the vagus nerve travel after the carotid sheath
Between the internal jugular vein and common carotid artery inferior to carotid bifurcation
Where does the pharyngeal branch leave the vagus nerve
At the level of the inferior ganglion
What fibers does the pharyngeal branch combine with after leaving inferior ganglion
Combine with fibers from glossopharyngeal nerve and sympathetic fibers from sympathetic trunk
What does the pharyngeal branch of vagus make when it joins fibers from the glossopharyngeal nerve and sympathetic fibers
The pharyngeal plexus
After the pharyngeal branch combines with other fibers in the neck what will vagal fibers provide motor supply to
Pharyngeal constrictor muscles, and levator veli palatine muscles of soft palate
Branches to carotid artery are also given off where
In the inferior ganglion
What do branches to the carotid artery carry
Viscerosensory fibers that relay info from chemoreceptors in carotid body to inferior part of nucleus for solitary tract
Where is the superior laryngeal nerve given off
Just inferior to inferior ganglion
What does the superior laryngeal nerve split into and what do they do
- external laryngeal provides motor supply to cricothyroid muscle
- internal laryngeal nerve carries sensory info from laryngeal mucosa as far inferior as vocal folds
Where does the recurrent laryngeal nerve supply motor fibers to
All muscles of larynx except the cricothyroid
Where does the recurrent laryngeal nerve carry sensory info from
The larynx inferior to vocal folds
What is unique about the path of the left recurrent laryngeal nerve
Comes off vagus and passes under aortic arch becoming the inferior laryngeal nurve
What does the inferior laryngeal nerve supply
Laryngeal musculature
Where does the right recurrent laryngeal nerve pass
Posteriorly under the subclavian artery before ascending
What do the superior and inferior cardiac branches carry
Parasympathetic information to the cardiac plexus
Where do the superior branches of the cardiac branch go
Leave vagus nerve and travel with great vessels to cardiac plexus
Where do branches of inferior cardiac branches go
Given off by recurrent laryngeal nerves and travel to cardiac plexus
What is unique about the superior and inferior cardiac branches
One branch will carry viscerosensory information concerning pressure of the wall of aorta. Nerve is stimulated when aortic pressure becomes too high
What is the path of vagus before contributing to pulmonary plexus
Enters thorax pass posterior to the root of ipsilateral lung
What is path of vagus near the esophagus
Right passes posteriorly and left passes anteriorly over esophagus contributing to esophageal plexus
Where does right vagus enter abdominal cavity and what does it become
Through esophageal opening becoming posterior vagal trunk
What does the right vagus do after entering abdominal cavity
Becomes posterior vagal trunk sending branches to posterior stomach and terminating in large celiac branch
Where does the large celiac branch send branches to
Duodenum, liver, kidneys, small intestine, and proximal 2/3 of large intestine
What makes up the superior messenteric plexus
Small intestine, and proximal 2/3 large intestine
What makes up the celiac plexus
Duodenum, liver, Small intestine
What does the left vagal nerve become after entering abdominal cavity
Anterior vagal trunk
Where does the anterior vagal trunk send branches to
Stomach, liver, pancreas, and superior part of the duodenum
What is bilateral transection
Both vagus nerves cut, patient would die do to no supply to necessary areas
What would lesions within the vault or close to skull produce
Widespread problems especially related to palate, pharynx, larynx
What would damage to the recurrent laryngeal nerve produce
Speech issues like hoarseness or decreased volume of speech
