3. Lung Volume and Ventilation

Question 1

What is the normal value of anatomical dead space?

Answer 1

150ml

Question 2

Anatomical dead space

Answer 2

The volume of gas occupied by the conducting airways. This gas is not available for exchange

Question 3

Tidal Volume (TV)

Answer 3

The volume of air breathed in or out of the lungs at each breath

Question 4

Expiratory Reserve Volume (ERV)

Answer 4

The maximum volume of air which can be expelled from the lungs at the end of a normal expiration

Question 5

Inspiratory Reserve Volume (IRV)

Answer 5

The maximum volume of air which can be drawn into the lungs at the end of a normal inspiration

Question 6

Residual Volume (RV)

Answer 6

The volume of gas in the lungs at the end of a maximal expiration

Question 7

Vital Capacity (VC)

Answer 7

Tidal volume + inspiratory reserve volume + expiratory reserve volume

Question 8

Total Lung Capacity (TLC)

Answer 8

Vital capacity + residual volume

Question 9

Inspiratory Capacity (IC)

Answer 9

Tidal volume + inspiratory reserve volume

Question 10

Functional Residual Capacity (FRC)

Answer 10

Expiratory reserve volume + residual volume

Question 11

FEV1

Answer 11

Forced expired volume in 1 second

Question 12

FEV1:FVC

Answer 12

Fraction of forced vital capacity expired in 1 second

Question 13

Ventilation

Answer 13

The movement of air in and out of the lungs

Question 14

Pulmonary (minute) ventilation

Answer 14

Total air movement into/out of lungs

Question 15

Alveolar ventilation

Answer 15

Fresh air getting to alveoli and therefore available for gas exchange

Question 16

What is the unit of pulmonary and alveolar ventilation?

Answer 16

L/min

Question 17

Hypoventilation

Answer 17

Decreased alveolar ventilation

Question 18

Hyperventilation

Answer 18

Increased alveolar ventilation

Question 19

Partial Pressure

Answer 19

The pressure of a gas in a mixture of gases is equivalent to the percentage of that particular gas in the entire mixture multiplied by the pressure of the whole gaseous mixture

Question 20

What are the commonly expressed units of pressure?

Answer 20

• mmHg

- kPa

Question 21

Why does partial pressure increase with increase [gas]mixture?

Answer 21

All gas molecules exert same pressure

Question 22

What is the standard atmospheric pressure?

Answer 22

760mmHg/ 101kPa

Question 23

How can Po2 and Pco2 vary?

Answer 23

With hypo/hyper- ventilation

Question 24

What happens to Po2 and Pco2 during hyperventilation?

Answer 24

• Po2 rises to abut 120mmHg

- Pco2 falls to about 20 mmHg

Question 25

What happens to Po2 and Pco2 during hypoventilation?

Answer 25

• Po2 falls to 30mmHg

- Pco2 rises to 100 mmHg