Question

after hyperventilating for several minutes, a person may develop short periods of apnea because multiple choice the level of co₂ decreases below the level necessary to stimulate the inspiratory center. blood ph would drop and inhibit inspiration. the level of oxygen has increased and inhibits the inspiratory center. oxygen in the lungs has not had time to diffuse into the blood. blood ph will rise and stimulate expiration.

Explanation:

Hyperventilation causes excessive exhalation of carbon - dioxide. The respiratory center in the brain is highly sensitive to the level of carbon - dioxide in the blood. When the CO₂ level drops below the threshold required to stimulate the respiratory center, short periods of apnea can occur. Blood pH would rise (not drop) due to the loss of acidic CO₂, which is related to respiratory alkalosis. An increase in oxygen level is not the main cause of apnea after hyperventilation, and oxygen diffusion into the blood is not the key factor here.

Answer:

the level of CO₂ decreases below the level necessary to stimulate the respiratory center