respiratory system n.
The integrated system of organs involved in the intake and exchange of oxygen and carbon dioxide between the body and the environment and including the nasal passages, larynx, trachea, bronchial tubes, and lungs.
| respiratory system The system of organs and structures in which gas exchange takes place, consisting of the lungs and airways in air-breathing vertebrates, gills in fish and many invertebrates, the outer covering of the body in worms, and specialized air ducts in insects. |
The organs in the body involved in respiration. Air enters the body through the nose and mouth and travels down the trachea, through the bronchial tubes, and finally into the lungs. Once in the lungs, the air is drawn into an enormous number of thin-walled sacs richly supplied with capillaries. The exchange of oxygen and carbon dioxide in the blood takes place in these tiny sacs.