Perfusion Relationships and Control of Ventilation

Homework 11

Ventilation-Perfusion Relationships and Control of Ventilation

Overall, the normal V/Q ratio is about

0.2

0.4

0.6

0.8

In a health individual in the upright position, the

V/Q ratio is highest in the lower lung regions

PACO2 is lowest in the upper lung regions

V/Q ratio is lowest in the upper lung regions

PACO2 is higher in the lower lung regions

1 only

2 only

4 only

3 and 4 only

When the V/Q ratio decreases, the 

PAO2 falls

PCCO2 increases

PACO@ rises

PCO2 decreases

1 only

3 only

2, 3, and 4 only

1, 2, 3, and 4

When the alveolar ventilation is 7L/min and the pulmonary blood flow is 9.5 L/min, the V/Q ratio is about

0.4

0.5

0.6

0.7

If tissue cells consume 275 mL of O2 per minute and produce 195 mL of CO2 per minute, what is the RQ?

0.65

0.7

0.8

0.96

List pulmonary disorders that increase the V/Q ratio:

__

__

__

__

__

List some pulmonary disorder that decrease the V/Q ratio:

__

__

__

The DRG consists chiefly of:

Inspiration neurons

Expiration neurons

Inspiratory and expiratory neurons

The VRG consists chiefly of:

Inspiration neurons

Expiration neurons

Inspiratory and expiratory neurons

Which of the following play a greater role in causing the ventilatory rate to increase in response to a decreased PaO2?

Carotid bodies

Aortic bodies

Which of the following has the most powerful effect on the respiratory components of the medulla?

Decreased O2

Increased H+

Decreased CO2

Increased pH

Which of the following protects the lung from excessive inflation?

Juxtapulmonary-capillary receptors

Hering-Breuer inflation reflex

Irritant reflex

When the systemic blood pressure increases and aortic and carotid sinus baroreceptors initiate reflexes that cause an/a

Increase heart rate

Decreased ventilatory rate

Increased ventilatory rate 

Decreased heart rate

A only

B only

C only

B and D only

Which of the following can cause a temporary cessation in breathing?

Sudden pain

Stimulation of proprioceptor

Sudden cold

Inhalation of noxious gases

A only

B only

C and D only

A and C only