The muscles of the larynx are extrinsic, passing between the larynx and parts around; and intrinsic, confined entirely to the larynx.
The intrinsic muscles are divided into respiratory and the phonatory muscles (the muscles of phonation). The respiratory muscles move thevocal cords apart and serve breathing. The phonatory muscles move the vocal cords together and serve the production of voice.
The main respiratory muscles are the posterior cricoarytenoid muscles. The phonatory muscles are divided into adductors (lateral cricoarytenoid muscles, arytenoid muscles) and tensors (cricothyroid muscles, thyroarytenoid muscles).