Larynx

The larynx is an inferior continuation of the oropharynx. It extends from the epiglottis (namely the glossoepiglottic and pharyngoepiglottic folds) to the inferior aspect of the cricoid cartilage. Inferiorly, it continues as the cervical trachea.

Gross anatomy

The larynx consists of a cartilage "skeleton", as well as internal structures that are divided into three subsites, mainly for the purposes of laryngeal cancer staging:

Relations

Arterial supply

Venous drainage

Lymphatic drainage

  • supraglottic: the supraglottic lymphatic network follows the superior laryngeal artery, piercing the thyrohyoid membrane and then draining into the superior deep cervical nodes and the pre-epiglottic nodes . 
  • subglottic: the infraglotttic lymphatic network drains to the inferior deep cervical nodes, following the inferior laryngeal artery, and/or the prelaryngeal (Delphian) nodes via the conus elasticus (aka the lateral cricothyroid ligaments) . 

Both the superior and inferior deep cervical nodes then drain into the right and left jugular trunks, which subsequently empty into the right lymphatic duct and the thoracic duct on the left.

Innervation

Development

  • the larynx is formed from the laryngotracheal groove, which is related to the caudal aspect of the floor of the primordial pharynx
  • the cartilages of the larynx develop from the 4 and 6 pharyngeal arches