The experimental report on the regulation of breathing movement in rabbits shows that the rising stage of normal breathing curve in rabbits is inhalation and the falling stage is exhalation.

analysis: inhale 2ml of air with a 2 ml syringe and the side tube of tracheal intubation, and slowly inject 2 ml into the lung after the breathing movement is stable, and clamp the other side tube at the same time. Pay attention to the change of respiratory rhythm and movement state.

After the test, immediately open the side tube and breathe normally. The same method is to use a syringe to extract lung gas at the end of exhalation and observe the difference of breathing state.

Experimental analysis of mild hypoxia:

When Po2 in inhaled air decreases, Po2 in alveolar air and arterial blood also decreases, so respiratory movement deepens and accelerates. Increased pulmonary ventilation. The direct effect of O2 deficiency on respiratory center is inhibition, which is gradually strengthened with the deepening of O2 deficiency. Therefore, the degree of O2 deficiency is different, and its performance is different.

In mild O2 deficiency, the transmission impulse through peripheral chemoreceptors such as carotid body excites the respiratory center more than the direct inhibition of O2 deficiency on the respiratory center, showing enhanced respiration.