The larynx (voice box) is the modified part of the respiratory tract sitting above the trachea and suspended from the hyoid bone. It consists of several cartilages that form the laryngeal skeleton, connected by the laryngeal membranes.

Its main functions are:

1. A protective sphincter for the rest of the airway
2. Phonation (speech generation), involving modifying airflow through the vocal cords controlled by the intrinsic muscles of the larynx.
3. Effort closure in coughing, sneezing, and abdominal straining.

Found in the anterior triangle of the neck, externally palpable features include the laryngeal prominence (Adam’s apple) and cricoid cartilage. The larynx is divided by the vocal cords into the upper supraglotticus. and lower infraglotticus. Muscles of the larynx are classed into intrinsic or extrinsic and respectively act on the laryngeal skeleton or modify the position of the larynx.

CLINICAL CORNER

Clinical conditions of the larynx include laryngitis (inflammation and associated swelling of the vocal folds generally causing pain, hoarseness and aphonia); vocal cord nodules (through overuse) and carcinoma (mainly squamous cell in smokers). Laryngeal nerves are at risk during thyroid surgery.