The cricothyroid muscle is the only laryngeal muscle NOT supplied by the recurrent laryngeal nerve. Which nerve supplies it and what is its primary action?

• A Internal laryngeal nerve; relaxes the vocal folds
• B External laryngeal nerve; tenses the vocal folds by tilting the thyroid cartilage forward ✓
• C Glossopharyngeal nerve; abducts the vocal folds
• D Hypoglossal nerve; elevates the larynx during swallowing

Explanation

The cricothyroid muscle is supplied by the external laryngeal nerve, a branch of the superior laryngeal nerve from the vagus. It tenses the vocal folds by tilting the thyroid cartilage forward on the cricoid. It is the only laryngeal muscle innervated by the external laryngeal nerve. All other intrinsic laryngeal muscles are supplied by the recurrent laryngeal nerve.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.