Which muscle is considered the primary abductor of the arytenoids?

The posterior cricoarytenoid muscle is recognized as the primary abductor of the arytenoid cartilages in the larynx. When it contracts, it pulls the arytenoids apart, which opens the vocal folds and allows for breathing. This abduction is essential for increasing the airway diameter during inhalation, facilitating airflow into the trachea and lungs.

Understanding the anatomy and function of the laryngeal muscles is crucial for comprehending their roles in voice and breathing. The posterior cricoarytenoid works in opposition to the adductor muscles of the larynx, which include the lateral cricoarytenoid and others, that bring the arytenoids together to close the vocal folds for phonation or protection of the airway. Thus, distinguishing the roles of these muscles highlights the posterior cricoarytenoid's unique function as the sole abductor, making it vital for understanding the mechanics of voice production and respiratory function.