Final answer:
The complex structure formed by many independent cartilaginous structures that marks where the upper airway ends and the lower airway begins is called the larynx.
Step-by-step explanation:
The complex structure formed by many independent cartilaginous structures that marks where the upper airway ends and the lower airway begins is called the larynx.
The larynx is located below the laryngopharynx and connects the pharynx to the trachea. It helps regulate the volume of air that enters and leaves the lungs.
The larynx is composed of several cartilage pieces including the thyroid cartilage, epiglottis, and cricoid cartilage. These cartilages form the major structure of the larynx.