Superior Laryngeal Nerve, Lateral View

Description

Running inferiorly from the vagus nerve (cranial nerve X) in the carotid triangle, the superior laryngeal nerve is presented in lateral profile as it bifurcates into the internal and external rami. The internal laryngeal nerve courses anteromedially toward the thyrohyoid membrane, traveling with the superior laryngeal artery and approaching the laryngeal inlet deep to the infrahyoid layer. The external laryngeal nerve descends more inferiorly along the laryngeal framework to reach the cricothyroid muscle, lying in close relationship to the superior thyroid vessels near the superior pole of the thyroid gland. Surrounding landmarks likely include the sternocleidomastoid laterally, the hyoid and thyroid cartilage medially, and portions of the cervical spine and shoulder girdle inferiorly. Orientation in this lateral neck view matters because the external branch of the superior laryngeal nerve is the structure surgeons most often fear during superior thyroid pedicle ligation in thyroidectomy; injury produces cricothyroid paresis and loss of high-pitch phonation that can be subtle on routine exam but career-changing for professional voice users. The internal branch, by contrast, carries supraglottic sensation and participates in the laryngeal cough reflex, so its blockade at the thyrohyoid membrane is a common step in awake fiberoptic intubation and other airway procedures. One nerve, two different problems. Educators can place this illustration directly into head and neck anatomy teaching on vagal branches, laryngeal innervation, and the relationship between the superior laryngeal nerve and the carotid sheath region. It also suits ENT and endocrine surgery texts discussing thyroidectomy exposure, superior pole anatomy, and nerve preservation, plus anesthesia training materials on internal superior laryngeal nerve block technique. Anatomical accuracy verified by SciePro's Medical Advisory Board.