What is the primary structure referred to as the Adam's apple?

The primary structure referred to as the Adam's apple is the thyroid cartilage. This cartilage forms a significant part of the laryngeal framework and is particularly prominent in males, creating the noticeable protrusion in the neck known as the laryngeal prominence. The thyroid cartilage is shaped like a shield and provides protection to the vocal cords located within the larynx. This prominence is more pronounced after puberty due to the influence of testosterone, which increases the size of the cartilage.

In contrast, the epiglottis serves a different function by covering the trachea during swallowing to prevent food from entering the airway. The cricoid cartilage also contributes to the structure of the larynx but is located beneath the thyroid cartilage and is more ring-like in shape. The term laryngeal prominence describes the visible angle of the thyroid cartilage but is not itself a separate anatomical structure. Thus, the thyroid cartilage is the correct answer as it directly denotes the structure commonly known as the Adam's apple.