Physiology of the larynx

The larynx consists of the cartilaginous-osseous framework, elastic membranes and ligaments, joints, muscles, nerves, vessels, and interior cavity. The laryngeal functions are the protection of the airway during swallowing, respiration (i. e. maintainance of the airway) and phonation. During the pharyngeal phase of swallowing the swallow reflex induces a laryngeal closure in three levels and a superior-anterior movement of the larynx and hyoid bone. The laryngeal airway is maintained by the circumference of the cricoid cartilage. Phonation is the phylogenetically recent function of the larynx and was made possible by the laryngeal descent. The sound production is explained according to the myoelastic-aerodynamic theory. The diagnostics of laryngeal diseases is performed in close cooperation between otorhinolaryngology and radiology. For diagnostic purposes, the physiology of the larynx requires to take into account not only morphological, but also functional aspects.