What is the primary function of the pharynx in animals?

The primary function of the pharynx in animals is to serve as a crossover point for air and food. This anatomical structure connects the nasal cavity and the mouth to the esophagus and the larynx, making it crucial for both the respiratory and digestive systems. In mammals and many other animals, when food is swallowed, it passes through the pharynx on its way to the esophagus, while air enters the larynx and continues to the trachea for respiration.

This dual role is essential for the effective functioning of both systems, allowing for the passage of food and air without interference. The design of the pharynx helps ensure that air can be directed into the trachea, while food can safely move into the esophagus.

While the pharynx may play a role in sound production, filtering of air, and respiration, its vital function as a crossover point for both air and food distinguishes it as the primary role in the context of this question.