Question

If the carotid and aortic chemoreceptors are denervated

A. Increasing alveolar PCO2 by 25 per cent fails to stimulate ventilation.

B. Halving the alveolar PO2 fails to stimulate ventilation.

C. The resting ventilation rate is depressed by more than 40 per cent.

D. Ventilation does not increase during exercise.

E. The ability to adapt to life at high altitude is impaired.

Answer 1

A. False Raised PCO2 can still stimulate breathing by acting on central chemoreceptors.

B. True In fact, hypoxia depresses ventilation by its action on the respiratory centre.

C. False Normal ventilation is driven mainly by the effect of CO2 on central chemoreceptors.

D. False Central and other peripheral effects increase respiratory drive in exercise.

E. True The individual is unable to increase ventilation in response to hypoxia.