The superior laryngeal nerve is a branch of the vagus nerve (cranial nerve X). At some variable point in the neck, it divides into internal and external branches. The internal branch provides sensory innervation of the larynx above the vocal cords. The external branch innervates the cricothyroid muscle, which is an adductor tensor of the vocal cords.

The superior laryngeal nerve lies close to the superior laryngeal artery. The internal branch of the superior laryngeal nerve lies on average 2.4 mm inferior to the greater horn of the hyoid bone.¹ The hyoid bone is U shaped in transverse scans of the neck. The superior laryngeal nerve enters the larynx through an aperture (ostium) in the thyrohyoid membrane together with the superior laryngeal artery and vein.

Block of the superior laryngeal nerve is sometimes used to facilitate awake fiberoptic intubation or transesophageal echocardiography.