[The protective reaction of external respiratory system to the long-term action of ecological factors].

Analyzes physiological manifestations and mechanisms of defense reaction of the external respiration system in response to two ecological factors: low air temperature and dust. Clinically healthy men (without clinical and laboratory signs of lung disease) were examined, living or working under conditions of low temperature or high dust content in the air. These two factors cause mobilization of reserve tissue of respiratory compartments of the lungs by involving the reserve acini in ventilation. This brings about an increase in FRC and RV, thus decreasing the harmful effect of the ecological factor and impairing gas metabolism in the lungs. Compensatory hyperventilation develops in response to it, expressed in increase of minute ventilation and decrease of ventilation efficiency. Competitive relationships between defense reaction and gas metabolism lead to external respiration stress.