Posterior cricoarytenoid muscle

The posterior cricoarytenoid muscle (in red) is located in the larynx. Image courtesy of Wikimedia Commons.

The Posterior Cricoarytenoid Muscle is a small, paired muscle that is located in the larynx. It is the only muscle that has the ability to open the vocal folds, and is therefore crucial for breathing.

Anatomy

The posterior cricoarytenoid muscle originates from the posterior surface of the cricoid cartilage and inserts into the muscular process of the arytenoid cartilage. It is innervated by the recurrent laryngeal branch of the vagus nerve.

Function

When the posterior cricoarytenoid muscle contracts, it pulls the arytenoid cartilages laterally. This action opens the vocal folds, allowing air to pass through the glottis and into the trachea. This muscle is therefore crucial for breathing and vocalization.

Clinical Significance

Damage to the posterior cricoarytenoid muscle or its nerve supply can result in vocal cord paralysis, which can cause difficulty breathing and changes in voice quality. Treatment typically involves surgery to reposition the vocal folds.

See Also

• Larynx
• Vocal folds
• Cricoid cartilage
• Arytenoid cartilage
• Vagus nerve