Final answer:
The pharynx is the passageway for both food or liquids and air, functioning as part of both the respiratory and digestive systems.
Step-by-step explanation:
The structure that serves as a passageway for both food and liquids as well as air is the pharynx. It is a tube-like structure located behind the nasal cavities and the oral cavity that extends to the openings of the esophagus and the larynx. The pharynx is subdivided into three regions: the nasopharynx, the oropharynx, and the laryngopharynx. The oropharynx and the laryngopharynx are specifically associated with the dual function of conducting air to the larynx and food to the esophagus. While the larynx is involved in voice production and conducts air, it does not serve as a passageway for food.