Respiratory System Functions Gas exchange: Oxygen enters blood and carbo leaves Regulation of blood pH: Altered by changing blood carbon dioxide levels Voice production: Movement of air past vocal folds makes sound and speech Olfaction Smell occurs when airborne molecules drawn into nasal cavity Protection: Against microorganisms by preventing entry and removing them Metabolism: Synthesize and metabolize different compounds(Nonrespiratory Function of the Lung)66 Respiratory System Functions • Gas exchange: Oxygen enters blood and carbon dioxide leaves • Regulation of blood pH: Altered by changing blood carbon dioxide levels • Voice production: Movement of air past vocal folds makes sound and speech • Olfaction: Smell occurs when airborne molecules drawn into nasal cavity • Protection: Against microorganisms by preventing entry and removing them • Metabolism: Synthesize and metabolize different compounds (Nonrespiratory Function of the Lung)