The vocal cords are formed by the vocal ligaments (free superior edge of the cricothyroid membrane) that are covered in mucous membrane. Although crucial for phonation, the vocal folds are constantly held open at other times by the posterior cricoarytenoids for breathing. Only when speaking do the vocal folds intermittently close, vibrating and causing sound waves as air is pushed out. When closed for phonation, … Continue reading Vocal cords

The laryngeal cavity starts as the the laryngeal inlet, and ends at the cricoid cartilage which is continous with the trachea below. The larynx is divided at the vocal folds into the vestibule (supraglottic cavity) above and infraglottic cavity below. The two vocal folds form the glottis, with the space in between being known as the rima glottidis. The vestibule is supplied by the superior … Continue reading Laryngeal cavity

The cartilages of the larynx are connected by several membranes. They include the thyrohyoid, cricothyroid and quarangular membranes. Thyrohyoid membrane The thyrohyoid membrane passes between the upper border of the thyroid cartilage and the upper border of the posterior surface of the hyoid bone. In the midline, it is thickened as the median thyrohyoid ligament. At the posterior edges are the lateral thyrohyoid ligaments, which … Continue reading Laryngeal membranes

The laryngeal skeleton comprises of 5 main cartilages: the cricoid, thyroid, epiglottis and the paired arytenoids. Epiglottis The epiglottis is a leaf-shaped elastic cartilage deep to the body of the hyoid. It never calcifies, unlike the other cartilages that are made of hyaline cartilage which can even ossify in old age. The stem of the “leaf” points inferiorly while the tip rises approximately 1cm above … Continue reading Laryngeal skeleton

The intrinsic muscles of the larynx can be divided into three groups based on on their actions. All are innerveated by the recurrent laryngeal nerve, except for cricothyroid which is innervated by the external branch of the superior laryngeal nerve (all branches of CN X) Laryngeal inlet muscles The inlet of the larynx is closed by aryepiglotticus, which runs in the aryepiglottic folds of the … Continue reading Intrinsic laryngeal muscles