 A study examining this issue found that liquid penetrated the airway significantly more frequently when a nasogastric tube was in place in men and women older than 70 years.That study and additional evidence indicates that under stressful conditions or system perturbations, older individuals are less able to compensate due to the age-related reduction in reserve capacity (add Pendergast reference) and are more at risk to experience airway penetration or aspiration.The tongue is the primary propulsive agent for pumping food through the mouth, into the pharynx while bypassing the airway and through to the esophagus.