cricoarytenoidei

The cricoarytenoidei muscles are a group of intrinsic muscles of the larynx that play a crucial role in voice production and airway control. They are divided into two main muscles: the posterior cricoarytenoid and the lateral cricoarytenoid.

The posterior cricoarytenoid muscle originates from the posterior lamina of the cricoid cartilage and inserts onto the muscular process of the arytenoid cartilage. Its primary function is abduction of the vocal folds, meaning it pulls the arytenoid cartilages apart, opening the glottis. This action is essential for breathing and for producing unvoiced sounds.

The lateral cricoarytenoid muscle originates from the lateral aspect of the cricoid cartilage and also inserts onto the muscular process of the arytenoid cartilage. This muscle opposes the action of the posterior cricoarytenoid by adducting the vocal folds, bringing them together. This adduction is necessary for closing the airway during swallowing and for producing voiced sounds.

Together, the cricoarytenoidei muscles are vital for regulating the tension and position of the vocal folds, directly influencing pitch and volume. Their coordinated action allows for the complex movements required for speech, singing, and protection of the lower respiratory tract. Damage or dysfunction of these muscles can lead to voice disorders and breathing difficulties.