Please enable JavaScript.
Coggle requires JavaScript to display documents.
CN X: Vagus, Vagus nerve disorders - Coggle Diagram
CN X: Vagus
Anatomy
Largest visceral sensory nerve
- Parasympathetic motor
- General and visceral sensory
- Branchial motor components
In the medulla, vagal fibers are connected to:
- Dorsal vagal motor nucleus = PVM
-
- Nucleus of the tracts solitarius = VS
- Spinal trigeminal nucleus = GS
Emerge from the medulla of the brainstem and exit the skull through jugular foramen
- Within jugular foramen the vagus nerve is in close proximity to the jugular bulb containing jugular gloms (=tympanic body) + neuron-like cells that monitor blood oxygen, carbon dioxide, pH levels in the aortic bodies
As the vagus nerve emerge through jugular foramen it lies within the same dural sheath as accessory nerve
Two sensory ganglia located on the vagus nerve:
- Superior (jugular)
- Inferior (nodosum)
In the neck
Lies between:
- Internal jugular vein
- Internal carotid artery
Descend vertically within the carotid sheath giving branches to:
- Pharynx
- Larynx
- Constrictor muscles
- Right recurrent laryngeal nerve branches = Right vagus nerve in the neck
- Left recurrent laryngeal nerve branches = Left vagus nerve in the thorax
Downwards, the nerve take different path on each side:
- Cardiac, pulmonary, esophageal plexuses
- From the esophageal plexuses => Right and left gastric nerves (=supply the stomach and most abdominal viscera
Visceral sensory (afferent) component
- Visceral sensation => Not appreciated at a conscious level of awareness
Visceral sensory fibers from abdominal viscera plexuses:
- Right and left gastric nerves of the vagus
Pass upward through = Esophageal hiatus of the diaphragm to merge with the plexus of nerves around the esophagus
-
Right and left vagus nerve joined by nerves carrying visceral sensory information from:
- Baroreceptors (=stretch R) in aortic arch and ChemoR (pH, CO2, O2 in blood) in the aortic bodies
- Larynx below the vocal cords in the recurrent laryngeal nerve
- Larynx above the vocal folds in the internal laryngeal nerve
- Mucous mb of the epiglottis and base of the tongue in the pharyngeal plexus
Central processes of nerve cell bodies in inferior vagal ganglion = Enter medulla + descend in tractus solitarius to enter the caudal part of the nucleus of the tractus solitarius
From the nucleus, bilateral connections important in the reflex control of:
- Cardiovascular
- Respiratory
- Gastrointestinal functions
are made with several areas of the reticular formation and the hypothalamus
-
-
-
Vagus nerve disorders
Glomus jugulaire tumor
-
Glomus cells = paraganglia cells that are a part of:
- Chemoreceptor system
<=> therefore, like chemoreceptors found in the carotid bodies, they monitor O2, CO2, and pH
Tumor typically compresses CNs IX, X, and XI and erodes the jugular foramen
Tx: surgical resection of the tumor and, in some cases, radiation therapy