Cranial Nerve X: Vagus Nerve

What’s unique about the Vagus Nerve?

The vagus nerve gets its name because it is the wanderer (think the word, “vagabond”). It wanders in that it has the largest area of distribution of all of the nerves. 

In addition to some motor and sensory functions, the vagus nerve also supports parasympathetic functions— the rest and digest functions— slowing down our heart rate, lowering the rate of respiration, and increasing the rate of digestion, all within the same nerve, making it a very complex nerve. 

What is the function of the nerve?

Motor: Soft palate muscles, pharyngeal and laryngeal muscles 
Sensory: General sense to the inferior pharynx and larynx, as well as the thoracic and abdominal organs 
Parasympathetic: Thoracic and abdominal viscera up to 2/3 of the transverse colon (supporting digestion, heart rate, blood pressure, and immune system responses)

What are the signs of dysfunction?

Signs of vagus nerve dysfunction may include:

• Abdominal pain, bloating, or changes in digestion
• Acid reflux
• Changes to heart rate, blood pressure, or blood sugar
• Difficulty speaking, swallowing, or loss of gag reflex
• Dizziness or fainting
• Hoarseness, wheezing, or loss of voice
• Loss of appetite, feeling full quickly, or unexplained weight loss
• Nausea and vomiting
• Depression and anxiety

How might this nerve be impacted?

The nerve may be impacted as a result of: 
• Trauma
• Stress
• Inflammation
• Compression or instability in the cervical region, or elsewhere along the pathway
• Diabetes
• Viral infections
• Surgery (particularly abdominal surgery)
• Scleroderma (hardening in blood vessels, internal organs, and digestive tract)

How can you work with this nerve?

• Sense a starting point based on the client’s intake- it could be in the abdominal region, the cervical region, or the head and brainstem. Offer space for decompression where it is needed.
• Visualize the pathway, from the medulla, moving alongside cranial nerves IX and XI to exit through the jugular foramen, moving down the cervical spine alongside the carotid artery and internal jugular vein to reach target areas, and extending down into additional targets in the thoracic and abdominal cavities. 
• Notice the quality of potency moving through the nerve.
• Hold space for any held patterns along the pathway to shift along the pathway.

The vagus nerve originates in the medulla oblangata of the brain stem.

The vagus nerve originates in the medulla oblangata of the brain stem.

The vagus nerve runs alongside cranial nerve IX, the glossopharyngeal nerve (superior) and cranial nerve XI, the accessory nerve (inferior).

The vagus nerve runs alongside cranial nerve IX, the glossopharyngeal nerve (superior) and cranial nerve XI, the accessory nerve (inferior).

The vagus nerve exits the base of the skull through the jugular foramen.

The vagus nerve exits the base of the skull through the jugular foramen.

The nerve parallels the path of the carotid artery and the internal jugular vein through the neck.

The nerve parallels the path of the carotid artery and the internal jugular vein through the neck.

Before doing so, at the inferior ganglion, the vagus nerve branches off to reach target areas in the head and neck. These branches include the accessory nerve, the superior laryngeal nerve, the carotid body branches, and the pharyngeal branch.

Before doing so, at the inferior ganglion, the vagus nerve branches off to reach target areas in the head and neck. These branches include the accessory nerve, the superior laryngeal nerve, the carotid body branches, and the pharyngeal branch.

The vagus nerve supplies the muscles of the soft palate. These are the small muscles that elevate during swallowing to block off entrance Into the nasal cavity, so food and liquids are directed down into the throat rather than up into the nasal cavit

The vagus nerve supplies the muscles of the soft palate. These are the small muscles that elevate during swallowing to block off entrance Into the nasal cavity, so food and liquids are directed down into the throat rather than up into the nasal cavity.

The vagus nerve also supplies the pharyngeal muscles - the constrictor muscles that help with swallowing and propelling food down towards the esophagus. The sensory component of the nerve has a similar area, providing sensation to the inferior aspect

The vagus nerve also supplies the pharyngeal muscles - the constrictor muscles that help with swallowing and propelling food down towards the esophagus. The sensory component of the nerve has a similar area, providing sensation to the inferior aspect of the pharynx.

The vagus nerve also provides motor innervation to some of the small muscles in our voice box, or the larynx, helping modulate the voice while talking.

The vagus nerve also provides motor innervation to some of the small muscles in our voice box, or the larynx, helping modulate the voice while talking.

Note that the glossopharyngeal nerve privided sensation in the oropharynx. So if the gag reflex is stimulated via the tongue, the glossopharyngeal nerve is being stimulated. In response to feeling the sensation, the motor response to vomit would be o

Note that the glossopharyngeal nerve privided sensation in the oropharynx. So if the gag reflex is stimulated via the tongue, the glossopharyngeal nerve is being stimulated. In response to feeling the sensation, the motor response to vomit would be occurring in the muscles in the throat, directed by the vagus nerve.

The vagus nerve has both sensory and parasympathetic function within the organs of the thoracic and abdominal cavities, up until 2/3 of our transverse colon.

The vagus nerve has both sensory and parasympathetic function within the organs of the thoracic and abdominal cavities, up until 2/3 of our transverse colon.