The organs that are part of the human respiratory system can be divided into three groups: lungs, airway and respiratory muscles.
The lungs are the right and the left lungs made of alveoli where gas exchange (entrance of oxygen and exit of carbon dioxide) takes place; the lungs are covered by the pleura (a serous membrane). The airway comprehends the nose, the pharynx, the larynx (including the vocal cords), the trachea, the bronchi and the bronchioles. The muscles upon which the breathing process depends are mainly the diaphragm and the intercostal muscles (muscles between the ribs).
