5 Written Questions

1. Impedance to ventilation caused by the movement of gas through the airways
2. • Alveoli at the apices have a higher resting volume and expand less during inspiration
   • Alveoli at the bases have a lower resting volume and receive approximately 4 TIMES as much ventilation as the apices
3. The sum of anatomical and alveolar dead space
4. WOB = ∆P × ∆V
5. 0.5 - 2.5 cmH₂O/L/sec

5 Matching Questions

1. Describe the transresipiratory pressure gradient (Prs)
2. Rule of thumb for changes in caliber of airway
3. Define hypoventilation
4. Conditions that can increase tissue viscous resistance
5. Describe exhalation below the resting level

1. a • The difference in pressure between the atmosphere and the alveoli
   • Prs = Palv - Pao
   • In a spontaneously breathing patient, Pao = Pbs = 1 atm (760 mmHg)
2. b A change in the caliber of an airway by a factor of 2 causes a 16-fold change in resistance (r⁴ = 16, if r = 2)
3. c Requires muscular effort to overcome the tendency of the chest wall to expand
4. d Ventilation that does not meet metabolic needs resulting in respiratory acidosis
5. e • Obesity
   • Fibrosis
   • Ascites

5 Multiple Choice Questions

1. 
   The ratio of driving pressure responsible for gas movement to the flow of the gas
   • cmH₂O/L/sec (cmH₂O per liter per second)
   • Think Pressure/Flow
   1. Formula for airway resistance
   2. Define tissue viscous resistance
   3. Define airway resistance
   4. Define compliance
2. In an obstructed lung there is the possibility of increased airway resistance in local areas
   • More driving pressure is needed to flow through airways
   • Less driving pressure is available for alveolar inflation
   • There is less alveolar volume change for a given pressure
   1. Describe the effect of changes in compliance and resistance on driving pressure and alveolar inflation
   2. Describe the pressure changes during inspiration and expiration
   3. Describe the differences in intraplural pressure during the breathing cycle
   4. Describe the differences in alveolar pressure (intrapulmonary pressure) during the breathing cycle
3. Ventilation is effective when it PaCO₂ is maintained at a level that maintains a normal pH
   1. Define minute ventilation
   2. Define alveolar ventilation
   3. Define hyperventilation
   4. Define effective ventilation
4. Volume of inspired gas that is wasted
   1. Define dead space
   2. Define airway resistance
   3. Define alveolar dead space
   4. Define anatomic dead space
5. 
   1. Define alveolar ventilation
   2. Dead Space Equation
   3. Alveolar ventilation equation
   4. Minute ventilation equation

5 True/False Questions

1. Define compliance → Volume change per unit of pressure change
   • Compliance is usually measured under static conditions (no airflow)

   True        False

2. Define Normal VT → Volume change per unit of pressure change
   • Compliance is usually measured under static conditions (no airflow)

   True        False

3. Average compliance of a healthy adult lung → • Supply O₂
   • Remove CO₂

   True        False

4. Identify the causes of long time constants → • Resistance or compliance is low
   • Lung unit will fill and empty more rapidly

   True        False

5. Describe the affects of alveolar ventilation in comparison to CO₂ production and removal → Requires muscular effort to overcome the tendency of the chest wall to expand

   True        False