Respiratory physiology

The normal FRV1/FVC ratio is 

• 0.95

• 0.80

• 0.60

•  0.50

• 0.40

The functional residual capacity is composed of the

• Expiratory reserve volume and residual volume

• Inspiratory capacity and vital capacity

• Expiratory reserve volume and tidal volume

• Inspiratory reserve volume and residual volume

• Expiratory capacity and tidal volume

Which of the following statements correctly defines the relationship between minute ventilation (VE), dead space ventilation (VD), and PaCO2?

• If VE is constant and VD increases, then PaCO2 will increase.

• If VE is constant and VD increases, then PaCO2 will decrease.

• If VD is constant and VE increases, then PaCO2 will increase.

• If VD is constant and VE increases, then PaCO2 will decrease.

• None of the above

The predominant stimulus for activation of hypoxic pulmonary vasoconstric­tion is

• Increased PaCO2

• Increased PaO2

• Decreased PaCO2

• Decreased PAO2

• None of the above

The P50 for normal adult hemoglobin is 

• 15

• 35

• 50

• 45

• 25

During a normal Vt (500 mL) breath, the transpulmonary pressure in­creases from 0 to 5 cm H2O). The product of transpulmonary pressure and Vt is 2,500 cmH2O-ml. This expression of the pressure-volume relationship during breathing determines what variable of respiratory mechanics?

• Lung compliance

• Airway resistance

• Pulmonary elastance

• Work of breathing

• Closing capacity

The most important mechanism for the transport of CO2 from peripheral tissues to the lungs is

• CO2 dissolved in plasma

• Carbonic acid

• Carbaminohemogiobin

• HC03-

• (CO3)-2

Which of the following muscles or muscle groups of respiration is not used for inspiration?

• Diaphragm

• Internal intercostal muscles

• External intercostal muscles

• Scalene muscles

• Sternomastoids

The anatomic dead space in a 70-kg male is

• 50 mL

• 150 mL

• 250 ml

• 500 ml

• 750 ml

Reynold's number is an important factor in the determination of

• O2 transport

• Surface tension

• Turbulent vs. laminar flow

• Physiologic dead-space ventilation

• Functional residual capacity