Vagus Nerve

Description

Running within the carotid sheath, the cervical vagus nerve (cranial nerve X) descends inferiorly from the skull base between the internal jugular vein laterally and the common carotid artery medially, then continues toward the thoracic inlet. Superficially, the sternocleidomastoid crosses the anterolateral neck, with the trapezius forming the posterolateral contour and the clavicle and scapula anchoring the shoulder girdle inferiorly and laterally. Yellow peripheral nerves at the root of the neck logically include elements of the brachial plexus emerging between the anterior and middle scalene muscles, positioned lateral to the great vessels and deep to the sternocleidomastoid. Cervical vertebrae sit posterior to the visceral column as a rigid backdrop. For teaching and for procedures, this relationship map matters. The vagus is a frequent structure at risk during carotid endarterectomy and other carotid sheath dissections, where traction or thermal injury can produce postoperative dysphonia via recurrent laryngeal involvement, or dysphagia when pharyngeal branches are affected. On the left, the vagus contributes to the cardiac and pulmonary plexuses and gives rise to the left recurrent laryngeal nerve looping under the aortic arch, while on the right the recurrent laryngeal loops under the subclavian artery, an asymmetry that explains sided differences in mediastinal and thyroid surgery risk. A nerve you do not want to “lose” in the field. Use this plate for head and neck anatomy labs, anesthesiology teaching on cervical vagal blocks and ultrasound-guided neck scanning landmarks, or surgical texts illustrating carotid sheath contents alongside adjacent brachial plexus anatomy at the thoracic inlet. It also fits otolaryngology and vascular surgery chapters discussing iatrogenic vagal or recurrent laryngeal neuropraxia. Anatomical accuracy verified by SciePro's Medical Advisory Board.