External laryngeal nerve

The external laryngeal nerve is one of the two branches of the superior laryngeal nerve and supplies the cricothyroid muscle.

Summary

• origin: arises as the smaller of the two branches of the superior laryngeal nerve at the level of the greater cornu of the hyoid bone
• course
  • descends posterior to the superior thyroid artery
  • pierces the inferior pharyngeal constrictor muscle at the level of the inferior thyroid tubercle to enter the cricothyroid muscle
• branches and supply
  • supplies the cricothyroid muscle (the only intrinsic muscle of the larynx not supplied by the recurrent laryngeal nerve)
  • small branches to the pharyngeal plexus
  • small branches to the inferior pharyngeal constrictor