Cricoarytenoid muscle

Cricoarytenoid muscle refers to a group of muscles that are crucial in the function of the larynx, particularly in the modulation of voice. The cricoarytenoid muscles are primarily involved in the opening and closing of the vocal folds, which is essential for phonation (voice production), breathing, and protecting the airway during swallowing. There are two main types of cricoarytenoid muscles: the posterior cricoarytenoid muscle and the lateral cricoarytenoid muscle. Each plays a specific role in the movement of the vocal folds.

Anatomy

The cricoarytenoid muscles are located in the larynx, which is situated at the top of the trachea. The larynx is made up of several cartilages, with the cricoid and arytenoid cartilages being particularly relevant to the function of the cricoarytenoid muscles.

Posterior Cricoarytenoid Muscle

The posterior cricoarytenoid muscle is the only muscle that opens the vocal folds. It originates from the posterior surface of the cricoid cartilage and inserts into the muscular process of the arytenoid cartilage. When it contracts, it pulls the arytenoid cartilages apart, which in turn abducts (opens) the vocal folds, allowing for breathing.

Lateral Cricoarytenoid Muscle

The lateral cricoarytenoid muscle, in contrast, aids in closing the vocal folds. It originates from the upper border of the side of the cricoid cartilage and inserts into the muscular process of the arytenoid cartilage. Contraction of this muscle pulls the arytenoid cartilages together, which adducts (closes) the vocal folds, facilitating phonation and protecting the airway during swallowing.

Function

The primary function of the cricoarytenoid muscles is to control the position and tension of the vocal folds. By regulating the opening and closing of the vocal folds, these muscles play a vital role in various aspects of voice production, including pitch and volume control. They are also essential in respiratory functions, as they help to regulate airflow in and out of the lungs.

Clinical Significance

Dysfunction of the cricoarytenoid muscles can lead to voice disorders, breathing difficulties, and challenges in protecting the airway during swallowing. Conditions such as laryngeal paralysis, vocal fold paresis, and cricoarytenoid arthritis can affect the function of these muscles, resulting in symptoms ranging from hoarseness and breathiness to complete loss of voice and airway obstruction.

Treatment

Treatment for cricoarytenoid muscle dysfunction depends on the underlying cause. Options may include voice therapy, surgical interventions, and in some cases, management of the underlying condition (e.g., controlling arthritis). Voice therapy aims to improve vocal function through exercises that strengthen or balance muscle activity. Surgical options may involve procedures to reposition the vocal folds or to alter the tension of the laryngeal muscles.

See Also

• Larynx
• Vocal folds
• Phonation
• Voice therapy