Arytenoid Cartilages

1. Overview

The arytenoid cartilages are a pair of small, pyramid-shaped structures in the larynx that play a central role in phonation, vocal cord movement, and airway protection. They are integral to the functioning of the glottis and are involved in controlling the tension, position, and opening of the vocal folds. As part of the internal laryngeal skeleton, they articulate with the cricoid cartilage and are the posterior attachment point for the vocal cords.

2. Location

The arytenoid cartilages are located:

• In the posterior part of the larynx, sitting atop the posterolateral lamina of the cricoid cartilage.

• Posterior to the thyroid cartilage and superior to the cricoid lamina.

• They form part of the posterior wall of the glottis and lie within the laryngeal cavity.

They are best visualized during laryngoscopy, positioned symmetrically on either side of the midline.

3. Structure

Each arytenoid cartilage has a pyramidal shape with three key surfaces and two processes:

• Apex: The pointed top, which supports the corniculate cartilage.

• Base: Broad and articulates with the cricoid cartilage below via a synovial joint.

• Vocal process: Projects anteriorly; provides attachment for the vocal ligament (true vocal cord).

• Muscular process: Projects laterally; attachment site for intrinsic laryngeal muscles, such as:

  • Posterior cricoarytenoid (abductor)

  • Lateral cricoarytenoid (adductor)

  • Thyroarytenoid (tensor/relaxer)

• Surfaces: Anterolateral, medial, and posterior, with ligament and muscle attachments.

The cartilages are composed of hyaline cartilage, which may undergo calcification or ossification with age.

4. Function

The arytenoid cartilages are key controllers of vocal cord movement and airway modulation. Their functions include:

• Phonation: Adjust position and tension of the vocal folds to produce sound.

• Airway control: Open and close the glottis during breathing, speaking, and swallowing.

• Support structure: Provide a movable framework for the posterior part of the glottis.

5. Physiological Role(s)

The arytenoid cartilages are involved in multiple vital respiratory and phonatory roles:

• Voice modulation: By altering tension, length, and position of the vocal cords, they affect pitch, volume, and timbre.

• Breathing: Abduction of vocal cords (via posterior cricoarytenoid muscles) opens the airway during inspiration.

• Swallowing: Adduction of vocal cords (via lateral cricoarytenoid and interarytenoid muscles) closes the glottis, preventing aspiration.

• Cough reflex: Closure of the glottis increases intrathoracic pressure before sudden release during coughing.

6. Clinical Significance

Vocal Cord Paralysis

Damage to the recurrent laryngeal nerve, which innervates most intrinsic laryngeal muscles, affects arytenoid cartilage motion. This can lead to:

• Unilateral or bilateral vocal fold immobility

• Hoarseness, breathy voice, or stridor

• Risk of aspiration

Common causes include thyroid surgery, trauma, or malignancy.

Arytenoid Dislocation

Rare but can occur during difficult intubation or trauma. Symptoms:

• Acute hoarseness

• Breathiness or loss of voice

• Dysphagia

Diagnosis is confirmed by laryngoscopy and treated with voice therapy or surgical repositioning.

Laryngeal Cancer

Tumors involving the vocal cords or posterior glottis may infiltrate the arytenoid region, affecting mobility and voice quality. Arytenoid fixation is a poor prognostic sign indicating deep invasion.

Aging and Ossification

With age, the arytenoid cartilages may ossify or calcify, which can affect laryngeal flexibility. This is often asymptomatic but may influence voice characteristics in the elderly.

Arytenoid Arthritis

Seen in autoimmune conditions like rheumatoid arthritis. Inflammation of the cricoarytenoid joint can cause:

• Pain during speaking or swallowing

• Hoarseness or laryngeal obstruction in severe cases

Managed with immunosuppressants and, in rare cases, surgical intervention.