Image of a human head and neck in median section in front of a red background. Parts of the cranium and facial bones (white-yellow-ish) are shown, the mandible and maxilla can be seen. The spine with its discs (grey) is shown. The choana, as well as the oral cavity, trachea and esophagus are red due to the mucosa. Muscles are hinted in the oral area. Cartilage as in the larynx is blue. As you can see, food (bolus, yellow-ish) should enter the esophagus while the trachea is closed by the epiglottis. If no or insufficiently, affected person chokes.