Food and liquid both go down the esophagus to the stomach, while air goes down the windpipe or bronchial tubes to the lungs. Both the esophagus and windpipe are connected. Occasionally, a small amount of food or liquid may start to go down the windpipe. Typical involuntary responses would include gagging, coughing, and choking. Difficulty in coughing up the food or liquid may cause a person to panic, while food lodged in the bronchial valve may quickly cause unconsciousness caused by the person being unable to cough out blockage, leading to a lack of of oxygen to the brain.