What is the primary abductor of the vocal folds (VF)?

The primary abductor of the vocal folds is the posterior cricoarytenoid muscle (PCA). The PCA plays a crucial role in the abduction, or opening, of the vocal folds during breathing. When the PCA contracts, it pulls the arytenoid cartilages away from each other, which subsequently opens the glottis—the space between the vocal folds—allowing air to flow freely into the trachea.

Understanding the function of the PCA is essential for grasping the mechanics of phonation and respiration. While other muscles are involved in the movement of the vocal folds, they primarily serve different functions. For instance, the interarytenoid muscle is responsible for adduction, or closing, the vocal folds, while the cricothyroid muscle adjusts the tension and pitch of the vocal folds by tilting the thyroid cartilage forward. The lateral cricoarytenoid muscle also contributes to adduction, bringing the vocal folds closer together during speech or vocalization.

Thus, recognizing the distinct role of the PCA in abducting the vocal folds highlights its importance in the overall dynamics of vocal fold movement and respiratory function.