Description
There are two groups of laryngeal muscles, the extrinsic and the intrinsic muscles.
The extrinsic muscles attach the larynx to adjacent structures, primarily the hyoid bone. These muscles assist with phonation (changes in pitch and voice quality) and deglutition by moving the larynx superiorly and inferiorly. These muscles include three of the infrahyoid muscles, the thyrohyoid, sternothyroid, and sternohyoid muscles, as well as three muscles of the pharynx, the inferior constrictor, stylopharyngeus, and palatopharyngeus muscles.
The intrinsic muscles of the larynx connect different portions of the larynx together. These include:
- cricothyroid muscle;
- posterior cricoarytenoid muscle;
- lateral cricoarytenoid muscle;
- transverse arytenoid muscle;
- oblique arytenoid muscle;
- thyroarytenoid muscle;
- vocalis muscle.
These muscles abduct and adduct the vocal folds to open and close the rima glottidis, they lengthen and tense the vocal folds, and they alter the laryngeal inlet by aiding the movement of the epiglottis.