[The relative contribution of the muscles of the chest cavity and diaphragm to the work of breathing under inspiratory resistive loading].

The inspiratory resistive load decreases the relative contribution of the diaphragm into formation of the respiratory volume, as has been show in anesthetised cats. The phenomenon can be due to both a sharp increase in the external intercostal muscles activity and to a fatigue of the diaphragmatic muscle in the inspiratory load. The contraphasic changes of these muscles' activity seem to be an adaptive response aiding to a more efficient overcoming of the resistance against breathing.