Cross-section of a human head in front of a white background. Deglutition is shown. The section shows part of the cranial bones and choana, as well as the backbone, oral cavity, trachea, and esophagus. It shows how e.g. food (bolus) gets in the trachea instead of the esophagus when choking. It leads to choking or suffocation in the worst case. Helpers can execute Heimlich’s maneuver as a first-aid measure.