Vagus nerve: cervical and thoracoabdominal branches (English)

The superior laryngeal nerve terminates via an internal branch (which carries sensory information from the supraglottic part of the larynx and epiglottis), and an external branch (which innervates the cricothyroid muscle). The vagus nerve then descends through the anterior triangle of the neck in the carotid sheath, travelling posterolateral to the internal carotid artery and the common carotid artery, where superior and inferior cervical cardiac branches are given off carrying GVE (parasympathetic) to and GVA (reflex) fibers from the cardiac plexus. At the root of the neck, the vagus nerve passes in front of each subclavian artery to enter the thorax, after which the right and left vagus nerves follow asymmetric courses. On the right side, the recurrent laryngeal nerve loops under the subclavian artery, while it’s counterpart on the left courses under the aortic arch before ascending through the neck. Both nerves innervate the intrinsic muscles of the larynx (except cricothyroid) as well as the mucosa of the infraglottic part of the larynx and trachea. In the thorax, the vagus nerve also gives rise to thoracic cardiac branches, bronchial and esophageal branches which together with branches of the sympathetic trunk, form the cardiac, pulmonary (not shown) and esophageal plexuses, respectively. The right and left vagus nerves, after contributing to the esophageal plexus, re-form and continue into the abdomen as the posterior and anterior vagal trunks, respectively. The posterior vagal trunk gives rise to the posterior gastric branch, most of the fibers of the celiac, pancreatic, splenic, renal, suprarenal (not shown) and intermesenteric plexuses, as well as the intestinal branch of the vagus nerve. The anterior vagal trunk gives off the anterior gastric branch and the hepatic branch which contributes to the hepatic plexus, but not the superior mesenteric ganglion which contains sympathetic fibers.