Representation of a human head in a cross-section in front of a white background. Deglutition is shown. Parts of the chranium and choana are visible, as well as the back bone, oral cavity, trachea and esophagus. Food (bolus) that gets into the trachea instead of the esophagus is shown here. This leads to choking or suffocation. Helpers can execute the Heimlich maneuver.