PGY 300 Respiratory Physiology Review

Interactions of Major Organ System of Human Body ○ Respiration involves ventilation (breathing), gas exchange (between air and capillaries in lung or systemic capillaries and tissues of body), and oxygen utilization (cellular respiration) ○ Respiration as two separate processes: gas exchange and cellular metabolism ■ Pulmonary respiration: primarily obtain oxygen for use via cells of body and to eliminate carbon dioxide produced by cells ● Pulmonary gas exchange: ventilation (between atmosphere and alveoli) ○ Diffusion: transport over short distances ○ Convection (bulk flow): transport over long distances ○ Both diffusion and convection driven by pressure differences ■ Cellular respiration: set of metabolic reactions within cell or organism converting nutrient biochemical energy into adenosine triphosphate (ATP) ○ Four integrated processes for respiration ■ Ventilation (breathing): inspiration and expiration ■ Exchange of O2 and CO2 between lungs and blood ■ Transport of O2 and CO2 in blood ■ Exchange of gases between blood and cells ■ Diseases affecting respiration can occur at any of these processes ● Anaerobic and Aerobic Respirations ○ Anaerobic respiration: glycolytic metabolism or glycolysis ■ No oxygen used; no carbon dioxide produced; but only small amount of ATP produced ○ Aerobic respiration ■ Glycolysis in cytoplasm; citric acid cycle in mitochondria