PATHWAY (ROUTE) TAKEN BY CO2:
blood(within capillary) >wall of capillary >wall of alveolar >moisture lining >alveolar space >bronchiole >bronchus >trachea >nose
PATHWAY (ROUTE) TAKEN BY O2:
nose >trachea >bronchus >bronchiole >alveolar space >moisture lining >wall of alveolar >wall of capillary >blood(within capillary)
