Vagus Nerve

nervus vagus (CN X)

The vagus nerve is the longest cranial nerve, wandering from the brainstem to the abdominal viscera and mediating the parasympathetic control of most thoracic and abdominal organs. Its recurrent laryngeal branches loop under the aortic arch on the left and subclavian artery on the right before ascending to the larynx, making them vulnerable to mediastinal and thoracic pathology. The right and left vagus nerves join the oesophageal plexus and reform as the anterior and posterior vagal trunks that enter the abdomen.

Region: Neck

Anatomical Data

Origin, Insertion & Supply

Origin	Cranial nerve X arising from the dorsal motor nucleus and nucleus ambiguus in the medulla

Clinical Relevance

Clinical Notes

Recurrent laryngeal nerve palsy from vagus or direct RLN injury produces hoarseness from vocal cord paralysis, with the left RLN more commonly affected because of its longer thoracic loop. Common causes include thyroid cancer, mediastinal malignancy, and iatrogenic injury during thyroid and thoracic surgery. Vagus nerve stimulation devices implanted in the neck are used to treat refractory epilepsy, depression, and inflammatory conditions by modulating the extensive vagal afferent system.

Pathology

Common Injuries & Conditions

Recurrent Laryngeal Nerve Palsy

Vocal cord paralysis from vagus or RLN injury producing hoarseness, aspiration, and loss of protective cough reflex, managed with voice therapy and surgical medialization for persistent palsy.