Protective Reflexes
Sneeze reflex clears the nose of irritating substances. Sensory receptors are stimulated causing a deep inspiration followed by an expiratory burst through the nose. The cough reflex clears the trachea and bronchii and may help to clear smaller airways by increasing intrathoracic pressure. Substances are removed from the airways by expectoration or swallowing. This reflex can be consciously initiated. Reflex bronchoconstiction protects alveoli from harmful fumes or cold air.