Chapter 2

Question 1

What can be measured using a simple spirometer?

Answer 1

• Tidal Volume
• Vital Capacity

Question 2

What needs helium dilution or body plethysmography to measure?

Answer 2

• Total Lung Capacity
• Functional Residual Capacity
• Residual Volume

Question 3

Why is Helium used in the helium dilution measurement?

Answer 3

• It has very low solubility in blood

Question 4

What does the use of body plethysmograph depend on?

Answer 4

• Boyle’s Law
• PV = K at constant temp

Question 5

What is total ventilation?

Answer 5

• Tidal Volume x Respiratory Frequency

Question 6

What is Alveolar Ventilation?

Answer 6

• The amount of fresh gas getting to alveoli
• (Vt - Vd) x n

Question 7

What is Physiologic Dead Space?

Answer 7

• Volume of gas that does not eliminate CO2

Question 8

Compare the Anatomic and Physiologic Dead Space.

Answer 8

Healthy individual
- They are the same
Acute and Chronic Lung Disease
- Physiologic Dead Space is increased

Question 9

What is the average tidal volume?

Answer 9

• 500ml

Question 10

What is the average total ventilation?

Answer 10

• 7500ml/min

Question 11

What is the average breathing frequency?

Answer 11

• 15/min

Question 12

How do you calculate alveolar ventilation?

Answer 12

• (tidal volume - anatomical dead space) x frequency of breathing

Question 13

How much can pulmonary capillary blood hold?

Answer 13

• 70ml

Question 14

What is the average pulmonary blood flow?

Answer 14

• 5000ml/min

Question 15

What is Total Lung Capacity?

Answer 15

• Total Volume the lungs can hold

Question 16

What is Vital Capacity?

Answer 16

• Total Volume Inhaled after a full exhale

Question 17

What is Tidal Volume?

Answer 17

• Average inhale/exhale amount (eupnea)

Question 18

What is Functional Residual Capacity?

Answer 18

• Total Volume in lungs following tidal volume exhale

Question 19

What is Residual Volume?

Answer 19

• Volume left in the lung following a full exhalation

Question 20

How is Helium used to measure functional residual capacity?

Answer 20

V2 = V1(C1-C2)/C2
V2 = FRC
V1 = Volume 1
C = concentration

Question 21

What is Boyle’s Law? how is it used in body plethysmography?

Answer 21

P1V1 = P2(V1 - change in V)
P1 = pressure in box prior to inspiratory effort
P2 = pressure in box after inspiratory effort
V1 = Pre-inspiratory box volume
Change in V = change in volume of box (or lung)

P3V2 = P4(V2 + change in V)
P3 = mouth pressure prior to inspiratory effort
P4 = Mouth pressure after inspiratory effort
V2 = Functional Residual Capacity

Question 22

What is the equation for Alveolar Ventilation? What is the best way to increase it?

Answer 22

VT = VD + VA
VTxn = VDxn + VAxn
VA. = VE. - VD.
Best way to increase VA. is to increase Tidal Volume

Question 23

Why are the lower regions of the lung better ventilated than the upper regions of the lung?

Answer 23

• Effects of gravity on the lung