The larynx, sometimes referred to as the voice box, is the superior end of the respiratory tube and acts as a valve to prevent food from entering the lower respiratory passages. It also, by virtue of the vocal folds (cords) found within the larynx, is capable of phonation or the production of sounds. These sounds are modified into intelligible speech by the pharynx, tongue, teeth, mouth and lips.

The skeleton of the larynx consists of a series of articulating cartilages (which are really modified tracheal rings) joined together by ligaments and membranes. This skeleton is responsible for maintaining the shape of this organ.

Several sets of small intrinsic muscles act to move the laryngeal cartilages collectively. Through the movements of these cartilages, the larynx varies the tension of the vocal folds and the opening between them to vary the pitch and volume of the sounds emitted.

These same muscles, by virtue of their affect on the opening between the vocal cords, control the entrance to the respiratory airway. The larynx receives motor innervation from cranial nerve X, the vagus nerve.

While we have artificially categorized and separated the neck, pharynx and larynx, it is important to realize the mandible, tongue, hyoid bone, larynx and trachea and esophagus are all interconnected by muscle, membranes and/or ligaments. All of these areas work together in activities such as chewing, swallowing, breathing and vocalization.