The arytenoid cartilages are a pair of small, pyramid-shaped structures sitting on top of the back portion of the cricoid cartilage in your larynx (voice box). Despite their tiny size, they are the primary movers of your vocal folds, controlling whether your airway is open for breathing or closed for speaking and swallowing.
Location and Basic Structure
Your larynx contains several cartilages that form its skeleton. The arytenoids sit at the very back of this framework, one on each side. Each one has two key projections. The front-facing projection, called the vocal process, anchors the vocal ligament that supports the inner edge of the vocal fold. The side-facing projection, called the muscular process, serves as the attachment point for the muscles that move the vocal folds open and closed.
The base of each arytenoid cartilage connects to the cricoid cartilage below it through a small synovial joint. This joint works somewhat like two concentric cylinders, allowing a combination of rocking and sliding motions. That range of movement is what gives the arytenoids their remarkable ability to pivot, tilt, and rotate, translating small muscular forces into precise adjustments of the vocal folds.
How the Arytenoids Control Your Voice
Voice production depends on two distinct types of vocal fold movement. First, the folds must be positioned correctly: pulled together to prepare for sound, or pulled apart for quiet breathing. Second, once the folds are in position, airflow from the lungs sets them vibrating rapidly to create sound. The arytenoid cartilages are responsible for the first part of this process, the large-scale positioning that sets the stage for vibration.
Three main muscle groups attach to the arytenoids and control this positioning:
- Posterior cricoarytenoid muscles: These originate from the back of the cricoid cartilage and insert into the muscular process of each arytenoid. They rotate the arytenoids outward, pulling the vocal folds apart and opening the airway. They are the only muscles that perform this job, which makes them essential for breathing.
- Lateral cricoarytenoid muscles: These run from the side of the cricoid cartilage to the muscular process and do the opposite. They rotate the arytenoids inward, bringing the vocal folds together to close the airway. This closure is the starting position for producing voice.
- Thyroarytenoid muscles: These connect the thyroid cartilage (the largest cartilage in your larynx) to the arytenoid cartilages. They stiffen the vocal folds and fine-tune their tension, which changes the amplitude and quality of vibration. The inner portion of this muscle, running alongside the vocal ligament, plays a different role than the outer portion: the outer fibers have a larger effect on arytenoid movement itself, while the inner fibers primarily adjust fold stiffness and pitch.
Together, these muscles give you control over pitch, volume, and voice quality. When the lateral muscles close the vocal folds tightly and the thyroarytenoid muscles increase tension, you produce a louder, higher-pitched sound. When the muscles relax, the folds loosen and pitch drops.
Breathing and Swallowing
The arytenoids do more than help you talk. Every breath you take requires the posterior cricoarytenoid muscles to rotate the arytenoids outward, widening the gap between the vocal folds (called the rima glottidis) so air can flow freely into the lungs. During vigorous exercise, this opening widens further to accommodate faster airflow.
When you swallow, the arytenoids do the reverse. The lateral cricoarytenoid and thyroarytenoid muscles bring the vocal folds firmly together while the epiglottis folds down over the top of the larynx. This double seal prevents food and liquid from entering your airway. Damage to the nerves or muscles controlling the arytenoids can compromise this protective closure, increasing the risk of choking or aspiration.
Changes With Age
Like many cartilages in the body, the arytenoids gradually harden over a lifetime. A true ossification process, in which cartilage is replaced by bone tissue, begins in the laryngeal cartilages as early as the twenties. In young adults (ages 25 to 35), ossification may appear only in small, deeper areas of the cartilage. After age 40, the process becomes more pronounced as cartilage tissue breaks down and is replaced by lamellar bone that can even contain blood-forming marrow tissue. In older adults, ossification is widespread.
This hardening is a normal part of aging, but it has practical implications. Ossified cartilage shows up on imaging like X-rays and CT scans, and it can sometimes be mistaken for abnormal calcification if a radiologist isn’t expecting it. The stiffening of the cricoarytenoid joint can also contribute to voice changes in older adults, reducing the range and flexibility of vocal fold movement.
Problems That Affect the Arytenoids
Several conditions can involve the arytenoid cartilages directly:
Contact granulomas are small growths that form on the part of the vocal folds overlying the arytenoid’s vocal process. They develop when the vocal folds slam together repeatedly or are irritated chronically. The two most common causes are voice overuse and acid reflux that reaches the throat. Symptoms include a persistent feeling of something stuck in the throat, a constant need to clear the throat, hoarseness, and a voice that tires easily.
Arytenoid dislocation or subluxation can occur when the cricoarytenoid joint is disrupted, most often during placement of a breathing tube. When the arytenoid is knocked out of its normal position, the vocal fold on that side can’t move properly, causing a breathy or weak voice and sometimes difficulty swallowing.
Cricoarytenoid joint arthritis affects people with systemic inflammatory conditions like rheumatoid arthritis. Inflammation and swelling at the joint restricts arytenoid movement, leading to hoarseness, a sensation of throat tightness, and in severe cases, difficulty breathing if both joints are affected and the airway narrows.
Role in Medical Procedures
The arytenoid cartilages are important visual landmarks during intubation, the process of placing a breathing tube into the trachea. When a clinician looks into the throat with a laryngoscope, spotting the epiglottis above and the arytenoids below confirms that the vocal cords lie between them and the trachea is just beyond. This makes the arytenoids a reliable guide for correct tube placement, especially when the vocal cords themselves are difficult to see.