Which muscle is NOT an intrinsic laryngeal muscle?

• A. Geniohyoid
• B. Interarytenoid
• C. Cricothyroid
• D. Thyroarytenoid

Answer: (A)

The main idea is the difference between intrinsic and extrinsic laryngeal muscles. Intrinsic muscles originate and insert on laryngeal cartilages, directly moving the vocal folds. Extrinsic muscles attach to the larynx but have another attachment outside the larynx, mainly supporting or elevating the larynx.

Geniohyoid sits outside the larynx; it connects the mandible to the hyoid bone and is part of the suprahyoid group. Its role is to elevate the hyoid and larynx during swallowing, not to move the vocal folds themselves. The other muscles listed are intrinsic: interarytenoid lies between the arytenoids and helps adduct the vocal folds; cricothyroid runs between the cricoid and thyroid cartilages and tensions the vocal cords; thyroarytenoid lies within the vocal folds and modifies tension and mass. Therefore, geniohyoid is the muscle that is not an intrinsic laryngeal muscle.