Final answer:
The nasopharynx is the part of the pharynx that serves as a passageway for air only, distinct from the oropharynx and laryngopharynx which both allow the passage of air and food.
Step-by-step explanation:
The part of the pharynx that is a passageway for air only is the nasopharynx. The pharynx is a tube-like structure that serves both the respiratory and digestive systems. The nasopharynx, which lies above the oropharynx and behind the nasal cavities, is exclusively involved in the passage of air and is therefore not a conduit for food. Conversely, the oropharynx and the laryngopharynx serve as passageways for both air and food. The oropharynx is flanked by the nasopharynx, oral cavity, and the laryngopharynx, while the laryngopharynx is bordered by the oropharynx superiorly and the esophagus and trachea inferiorly.
The part of the pharynx that is a passageway for air only is the nasopharynx. The pharynx is a tube-like structure that connects the nasal cavity and the back of the mouth to other structures lower in the throat. It has three subdivisions, with the nasopharynx being the most superior and involved only in breathing and speech. The oropharynx and laryngopharynx, on the other hand, are used for both breathing and digestion.