The vagus nerve, also known as the tenth cranial nerve (CN X), is the longest cranial nerve in the body. It originates in the brainstem, specifically from the medulla oblongata, and exits the skull through the jugular foramen. From there, it travels down the neck within the carotid sheath, positioned between the internal carotid artery and the internal jugular vein
. The nerve has two branches-right and left vagus nerves-that run down the respective sides of the body:
- The right vagus nerve passes anterior to the right subclavian artery, then descends into the thorax traveling posterior to the superior vena cava and right main bronchus. It contributes to cardiac, pulmonary, and esophageal plexuses before passing through the diaphragm to the abdomen
- The left vagus nerve travels between the left common carotid artery and left subclavian artery, descends along the aortic arch, gives off the left recurrent laryngeal nerve, and continues into the thorax and abdomen via the esophageal hiatus
The vagus nerve extends from the brainstem through the neck, chest, and abdomen, innervating multiple organs including the heart, lungs, digestive tract (down to the large intestine), liver, spleen, and kidneys. It plays a critical role in autonomic regulation of involuntary functions such as heart rate, breathing, and digestion
. In summary, the vagus nerve is located starting in the brainstem, descending through the neck alongside major blood vessels, and extending into the thorax and abdomen to innervate various vital organs throughout the body
