Vagus nerve Flashcards
nuclie’s of the vagus nerve
- ambiguous nucleus
- medial ala cinerea nucleus
- solitary tract nucleus
- lateral ala cinerea nucleus
- spinal trigeminal nucleus
location and function of ambiguous nucleus
- medulla
- SVM
location and function of medial ala cinerea nucleus
- medulla long nucleus lying vertically upper lies in vagal triangle, lower end lies in central grey matter of medulla
- parasymp. preggl fibers GVM
location and function of solitary tract nucleus
- medulla
- tast SVS *commissural nucleus plays a role in heart rate and blood pressure regulation
location and function of lateral ala cinerea nucleus
- part of solitary tract in cranial open part of medulla
- GVS
location and function of spinal trigeminal nucleus
- extends down principal nucleus into medulla until c1-c2 segments of spinal cord
- protopathic sensibility GSS
Brain exit of Vagus nerve
lateral paraolivary sulcus
dura pentration of Vagus nerve
jugular foramen pars nervosa
skull exit of Vagus nerve
jugular foramen pars nervosa
ganglia of Vagus nerve
- superior jugular ggl
- inferior nodose ggl
superior (jugular) ggl
small sensory ggl on vagus as it traverses the jugular foramen
-cell bodies are for protopathic sensibility of dura and external ears terminal in spinal trigeminal nucleus
inferior (nodose) ggl
large sensory ggl of vagus, ant to the internal jugular vein
-cell bodies are for taste sensation and for viscerosensory sensation
where do the vagus nerve go?
both right and left vagus nerve decend from the brain in the carotid sheath lateral to the carotid artery, enter the thoracic cavity through the thoracic inlet
right vagus nerve
-gives rise to right recurrent laryngeal nerve
-hooks around right subclavian artery ascends into next between trachea and esophagus
-cosses ant. to the right subclavian artery and runs post. to the sup vena cava and descends post. to the right main bronchus an contributes to
*cardiac
*pulmonary
*esophageal
plexuses.
-forms the post vagal trunk at lower part of the esophagus and enters the diaphragm through the esophageal hiatus
left vagus nerve
enter thorax between left common carotid artery and left subclavian artery and descends on the aortic arch
- gives rise to left recurrent laryngeal nerve which hooks around the aortic arch to the left ligamentum arteriosum
- ascends between the trachea and esophagus
- continues into the esophageal plexus and enters the abdomen as the anterior vagal trunk in the esophageal hiatus of the diaphragm
branches of the vagus nerve
- meningeal branch
- arnolds nerve
- pharyngeal branches
- superior laryngeal nerve
- recurrent laryngeal nerves
- cardiac branches
- esophageal branches
- pulmonary branches
- anterior and posterior vagal trunks
meningeal branch
inn of the post. part of dura matter
auricular branch of vagus nerve (arnold’s nerve)
from sup. ggl inn 1/3 of the tympanic membrane and external acoustic meatus and the pannus of the auricle + small dorsal part
pharyngeal branches
combines in the pharynx with the pharyngeal branches of glossopharyngeal nerve to form the pharyngeal nerve plexus which is a mix motor/ sensory plexus
pharyngeal nerve plexus
- sensory inn of the mucosa of lower pharynx and epiglottis
- taste sensation of accessory taste buds on epiglottis
- motor branches for soft palate and pharyngeal muscles:
- lower 1/2 of middle constrictor of pharynx
- inferior constrictor of pharynx
- palatopharyngeus muscle
- salpingopharyngues muscle
- palatoglossus muscle
- leavtor veli palatini muscle
superior laryngeal nerve
- branch of vagus n. at inferior ggl
- at thryoid cartilage it divides into two branches
- internal laryngeal nerve
- external laryngeal nerve
internal laryngeal nerve
sensory branch that supplies the mucous membrane of larynx superior to the vocal folds
*sensory + parasympathetic
external laryngeal nerve
motor branch that supplies the cricothyroid muscle
recurrent laryngeal nerves
has:
- tracheal branches
- esophageal branches
- inferior laryngeal nerve
tracheal branches
parasympathetic, sensory & motor innervation of the mucosa and smooth muscle of trachea
esophageal branches
parasymp, sensory and motor innervation of the upper esophagus
inferior laryngeal nerve
terminal branch of the recurrent laryngeal nerve as the latter passes deep to the inferior pharyngela constrictor to supply
- laryngeal mucosa
- inferior vocal folds
- all the laryngeal muscles EXCEPT the cricothyroid muscle
cardiac branches
conducts presynaptic parasymp fibers to and relex afferent fibers from the cardiac plexus
cardiac plexus
- superior cervical cardiac branch
- inferior cervical cardiac branch
- thoracic cardiac branches
esophageal branches
includes both branches passing directly from vagi and the branches from the recurrent laryngeal nerves that form the esphageal nerve plexus which surrounds esophagus, supplying it and adjacent portions of the pericardium
pulmonary branches
bronchial branches of the vagus nerve at the hilium, from them various branches accompany the bronchi and arteries into the the lung
anterior and posterior vagal trunks
ant. mainly from left vagus and post from the right as the stomach rotates, they supply parasymp., secretomotor, afferent fibers for the entire GI tract untill the left colic flexure.
supply of the anterior and posterior vagal trunks
- gastric branches (ant & post) (stomach)
- celiac branches (celiac plexus around the trunk)
- heaptic, pyloric and gall bladder branches(hepatic plexus)
- vagal fibers for small and large intestines up to the left coic flexure accompanying the mesenteric arteries
