Choking occurs when a piece of food becomes firmly lodged in the

The answer is Trachea. When there is an object blocking the windpipe, it interferes with the flow of air to the lungs and the reflex reaction of the body is to try and dislodge the object through forceful  coughing. The chocking interferes with gaseous exchange in the lungs hence the brain is not supplied with oxygen hence the person can lose consciousness if the choking persists for some time.