Larynx

The larynx is a structure in the respiratory tract that connects the nose and mouth on one side to the windpipe (trachea) on the other. It consists of cartilage (hard elastic tissue) and small muscles that control movement. The medical term is larynx.

It has two major functions: breathing and protection of the airway, and voice production. When swallowing, a flap called the epiglottis covers the opening of the larynx, allowing food and liquid to pass into the esophagus rather than the windpipe.

Structure

The larynx is supported by several cartilages. The most prominent is the shield-shaped thyroid cartilage, which in some men is visible at the front of the neck (called the Adam's apple), and a smaller ring-shaped cartilage below it. Inside are two pairs of folds called the vocal folds. Small muscles tense, stiffen or relax these folds.

How voice is produced

When air from the lungs passes through the gap between the vocal folds, the folds vibrate. This vibration creates sound waves in the air. The pitch depends on how tightly the folds are tensed and their thickness. The sound is then shaped by the nose, mouth, tongue and lips into speech. Voice is therefore a combination of air, vibration and shaping.

Health and disorders

Damage to the vocal folds causes hoarseness or temporary loss of voice, usually after a cold or overuse of the voice. Smoking and exposure to chemicals are associated with increased risk of laryngeal cancer. During puberty, the larynx grows and the vocal folds lengthen, causing the voice to deepen. When the airway is blocked, doctors can make an opening in the neck to allow breathing.