What is the endpoint of the upper airway?

The endpoint of the upper airway is the glottis opening. This anatomical structure marks the transition point from the upper airway, which consists of the nasal passages, nasopharynx, oropharynx, and laryngopharynx, to the lower airway. The glottis is the part of the larynx that contains the vocal cords and the opening between them, which plays a crucial role in breathing and phonation. It serves as the entry point for air into the trachea and subsequently into the lower respiratory tract, including the bronchi and alveoli.

Understanding where the upper airway ends and the lower airway begins is important in clinical practice, especially during procedures related to airway management, such as intubation or ventilation, as it helps ensure proper placement and function of airway devices.