Exam 11: Control of Ventilation

Which of the following is (are) true of the Hering-Breuer reflex? I.It results in an expiratory discharge pattern. II.In adults it is activated only at small tidal volumes. III.It has been suggested to be an important control mechanism in quiet breathing. IV.It is important in regulating the respiratory rate and depth during moderate to strenuous exercise.

Which of the following peripheral chemoreceptors has the greatest influence over the respiratory centers?

Which of the following statements are true of the DRG? I.It consists mainly of inspiratory neurons. II.It sends impulses to the phrenic and external intercostal motor nerves in the spinal cord. III.It provides the main stimulus for inspiration. IV.These neurons are involved in the Hering-Breuer and Head's reflexes.

The inhibitory neurons that switch off the inspiratory ramp arise from which of the following areas? I.VRG II.DRG III.Pulmonary stretch receptors IV.Pneumotaxic center

When stimulated, the stretch receptors will have which of the following effects on respiration?

Arterial hypoxemia does not stimulate ventilation until PO₂ reaches which level?

How much reduction in cerebral blood flow is anticipated for every 1 mm Hg acute reduction in PaCO₂?

Which of the following conditions will elicit the strongest Hering-Breuer reflex?

What is the explanation for the suppression of the ventilatory stimulus present in subjects chronically exposed to high altitudes?

Which of the following statements are true of CO₂ and cerebral blood flow? I.Increased PCO₂ dilates cerebral vessels, raising cerebral blood flow. II.Normal ICP is less than 10 mm Hg. III.To sustain the cerebral blood flow, a cerebral perfusion pressure (CPP) of approximately 60 mm Hg must be maintained. IV.Increased PCO₂ constricts cerebral vessels, decreasing cerebral blood flow.

An acute increase in the PaCO₂ has an extremely powerful effect on ventilation.How long does it typically take for this effect to weaken?

What is considered the maximum level of PaO₂ on room air at maximal hyperventilation?

What is the explanation for the lack of ventilatory stimulation when anemia and hypoxemia are present?

What is the primary mechanism that drives ventilation in humans?

Which of the following are considered effects of stimulation of the motor component of the vagovagal reflexes? I.Bronchoconstriction II.Laryngospasm III.Coughing IV.Bradycardia

Transection of the brainstem between the pons and medulla results in which of the following respiratory patterns?

Which of the following procedures may elicit vagovagal reflexes? I.Endotracheal intubation II.Airway suctioning III.Administration of aerosol therapy IV.Bronchoscopy

Which of the following effects are associated with stimulation of the J-receptors? I.Rapid, shallow breathing II.Sensation of dyspnea III.Expiratory narrowing of the glottis IV.Croup in infants

Which of the following reflexes is (are) caused by stimulation of the irritant receptors? I.Bronchoconstriction II.Coughing III.Bradypnea IV.Narrowing of the glottis

Stimulation of which of the following receptors explains the stimulation of ventilation after the splashing of cold water on the skin?