About larynx cancer

The Larynx

A basic understanding of the anatomy of the larynx is necessary before laryngeal reconstruction can be defined. The larynx is positioned in the anterior neck, slightly below the point where the pharynx divides and gives rise to the separated respiratory and digestive tracts. Because of its location, the larynx plays a critical role in normal breathing, swallowing, and speaking.

The framework of the larynx is comprised mainly of two cartilages, the upper thyroid cartilage (shield-shaped structure) and the lower cricoid cartilage. The cricoid cartilage is shaped like a signet ring with the larger portion of the ring in the back. Below the cricoid are the rings of the trachea. The epiglottis lies superiorly.

Frontal view on the larynx	Internal view on the larynx

The vocal folds lie in the center of this framework in an anterior-posterior orientation. When viewed from above the right end left folds appear as a ‘V’-shaped structure. At the rear of the larynx on each side, each vocal fold is attached to a small arytenoid cartilage. Many small muscles also attach to the arytenoids. These muscles contract or relax during the various stages of breathing, swallowing, and speaking, and their action is vital to the normal function of the larynx. Control over these muscles is provided by two branches of the vagus nerve: the recurrent laryngeal nerve and the superior laryngeal nerve.

Phonation is a complicated process in which sound is produced for speech. During phonation, the vocal folds are brought together near the center of the larynx by muscles attached to the arytenoids. As air is forced through the vocal folds, they vibrate and produce sound. As the sound produced by the larynx travels through the throat and mouth, it is further modified to produce speech.

Axial section at glottic level during respiration. Vocal folds are in opened position.	Axial section at glottic level during phonation. Vocal folds vibrate during expiration.