Which reflex is associated with laryngeal protection against foreign substances?

The laryngeal reflex activity, which includes coughing and spastic closure, plays a vital role in protecting the airway from foreign substances. When something irritates the larynx or triggers the laryngeal lining, this reflex occurs as a protective mechanism. It is designed to expel foreign objects or irritants from the airway, thereby preventing aspiration and maintaining clear air passages. The cough reflex specifically helps to forcibly expel substances that may have entered the larynx or trachea, allowing for a protective action to restore normal breathing.

While the swallowing reflex also involves airway protection by temporarily closing the larynx during swallowing, its primary function is to ensure food moves safely into the esophagus rather than the airway. The respiratory reflex, on the other hand, primarily governs the rhythm of breathing and does not directly serve to protect against foreign substances. The phonation reflex relates to producing sound and enabling speech, but it does not have the same protective function as the cough and spastic closure components of laryngeal reflex activity. Thus, laryngeal reflex activity is specifically geared toward the defense of the airway, making it the correct answer for this question.