Practice Questions: Respiratory Regulation


1. A stroke that destroyed the respiratory center of the medulla would be expected to lead to

A. immediate cessation of breathing
B. apneustic breathing
C. ataxic breathing
D. rapid breathing (hyperpnea)
E. none of the above, since breathing would remain normal

2. The afferent (sensory) endings for the Hering-Breuer reflex are stretch receptors (mechanoreceptors) in the

A. aorta and carotid arteries
B. arteries in the cerebral circulation
C. lungs
D. heart
E. diaphragm and intercostal muscles

3.  Stimulation of the reticular activating system of the brainstem (RAS) plays what role in ventilation?

A. stimulates ventilation
B. inhibits ventilation
C. stimulates inhalation but inhibits exhalation (apneustic breathing) D. stimulates exhalation but inhibits inhalation

E. causes ventilation to cease entirely ("Ondine’s Curse")

4. Hyperventilating allows one to hold one’s breath for a longer period of time, because hyperventilation

A. increases the oxygen reserve of systemic arterial blood
B. decreases the PCO2 of systemic arterial blood
C. decreases the pH of systemic arterial blood
D. increases brain blood flow
E. none of the above, since hyperventilation reduces the time one can voluntarily stop breathing

5. The most important afferent (sensory) receptors for the respiratory response to systemic arterial carbon dioxide (Pa-CO2) are the

A. CO2 receptors of the aortic and carotid bodies
B. H+ receptors of the aortic and carotid bodies
C. CO2 receptors in the medulla of the brain
D. H+ receptors in the medulla of the brain
E. CO2 receptors in the airways and lungs