Final answer:
The pharynx is the tube that lies behind the oral and nasal cavities, connecting them to the esophagus and larynx, and functions in both respiration and digestion.
Step-by-step explanation:
The inferior funnel-shaped tube that lies behind the oral and nasal cavities is the pharynx. This organ plays a crucial role in both the respiratory and digestive systems. The pharynx is a tubular structure made up of skeletal muscle, lined with mucous membrane, and extends from the posterior part of the oral and nasal cavities to the openings of the esophagus and larynx. It is divided into three segments: the nasopharynx, which is only involved in breathing and speech, the oropharynx, and the laryngopharynx, both of which are used for breathing and digestion.
The nasopharynx is located above the oropharynx and, in turn, the oropharynx is continuous with the laryngopharynx below. The anterior portion of the laryngopharynx opens to the larynx, leading air into the bronchial tree, while its inferior border connects to the esophagus for passage of ingested foods.