Final answer:
During swallowing, the soft palate and uvula rise to close off the entrance to the nasopharynx, while the larynx and cartilaginous epiglottis function to block the trachea and bronchi. This prevents food and liquid from entering the nasal cavity.
Step-by-step explanation:
During swallowing, the soft palate and uvula rise reflexively to close off the entrance to the nasopharynx, preventing food and liquid from entering the nasal cavity. At the same time, the larynx is pulled superiorly and the cartilaginous epiglottis folds inferiorly, covering the glottis and effectively blocking access to the trachea and bronchi. This process ensures that food goes into the esophagus and not the trachea.