Thyroid cartilage

Thyroid cartilage is the largest of the nine cartilages that make up the laryngeal skeleton, the cartilage structure in and around the trachea that contains the larynx. It is named for its shield-like shape.

Structure

The thyroid cartilage is composed of two laminas that form the walls of the thyroid cartilage. These laminas are fused at the front, forming the laryngeal prominence, commonly known as the "Adam's apple". The superior thyroid notch is a small notch in the top of the laryngeal prominence. The angle at which the laminas meet can vary between individuals and between sexes, with a sharper angle (less than 90 degrees) often seen in males.

The posterior side of the thyroid cartilage is open, allowing for the passage of the vocal cords. The superior and inferior thyroid horns project from the back of the laminas. The superior horns are longer and are connected to the hyoid bone by the thyrohyoid membrane. The inferior horns are shorter and articulate with the cricoid cartilage.

Function

The thyroid cartilage protects the vocal folds ("vocal cords"), which are located directly behind it. When the vocal folds vibrate, they produce sound that is then modulated by the rest of the vocal tract to produce speech. The size and shape of the thyroid cartilage can affect the pitch and quality of the voice.

Clinical significance

The thyroid cartilage can be felt through the skin of the neck, and its size and shape can be altered through surgery, such as thyroid cartilage reduction or chondrolaryngoplasty, often sought by those undergoing gender transitioning. It can also be injured by trauma to the neck, such as a blow to the throat or strangulation.

See also

• Larynx
• Cartilage
• Vocal folds
• Adam's apple

References

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  External view of the larynx
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  Detailed view of the larynx