Specifics as to the role this system plays in ventilation, how respiration and gas exchange transpire, and the role the lungs play in the renin-angiotensin-aldosterone system are presented. The functions of these structures have been categorized, relating specific components to the purpose relative to ventilation and perfusion .

At the capillary-alveolar bed, the primary function of the respiratory system is gas exchange . This section has delved into the physiology of the respiratory system, and how it fits in the cardiopulmonary system .

perfusion — vascular circulation powered by the pumping action of the heart that delivers oxygen and other nutrients to body tissues. cardiovascular system — structurally unique insofar as it contains the muscular four-chambered heart (the pump), fluid/blood volume (the tank), and the blood vessels (the pipes). gas exchange — the transfer of oxygen and carbon dioxide; takes place at the alveolar-capillary bed. respiration — the action of breathing, including inhalation and exhalation.