The respiratory system includesthe passages that transport airto and from the lungs, and airsacs in which gas exchangesoccur. Respiration is the entireprocess by which gases areexchanged between theatmosphere and the body cells.
I. Organs of the Respiratory System The respiratory system includes the nose, nasal cavity, sinuses, pharynx, larynx, trachea, bronchial tree, and lungs. The upper respiratory tract includes the respiratory organs outside the thorax; the lower respiratory organs within the thorax.