The human body's respiratory organs are located in the chest and upper abdomen. These organs, collectively referred to as the respiratory system, consist of three major parts and supply the body with the constant stream of oxygen necessary to stay alive.
The three major parts of the respiratory system are the airway, the lungs and the muscles of respiration. The airway sits at the top of the respiratory system and starts with the trachea, which reaches up to the base of the neck. The lungs are below the airway and the main muscle of respiration, the diaphragm, sits at the bottom of the respiratory system at the point on the body where the chest and abdomen meet.