Ventilation and compliance 1

Question 1

Spirometer

Answer 1

Apparatus used to measure the volume of air expired and inspired in the lungs - breathed in and out

Question 2

Anatomical dead space + the volume

Answer 2

Volume is about 150ml

Volume of gas occupied by the conducting airways and this gas is not available for gas exchange

Question 3

Residual volume

Answer 3

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

Question 4

Expiratory reserve volume

Answer 4

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

Question 5

Tidal volume

Answer 5

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

Question 6

Inspiratory reserve volume

Answer 6

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

Question 7

Vital capacity

Answer 7

IRV+TV+ERV

Question 8

Total lung capacity

Answer 8

Vital capacity + RV

Question 9

Functional residual volume

Answer 9

RV+ERV

Question 10

Inspiratory capacity

Answer 10

TV + IRV

Question 11

FEV1:FVC

Answer 11

Fraction of forced vital capacity expired in one second

Question 12

What units is ventilation measured in?

Answer 12

L/min

Question 13

Pulmonary ventilation

Answer 13

Total air movement into/out of lungs

Question 14

Alveolar ventilation

Answer 14

Fresh air getting to alveoli and therefore available for gas exchange

Question 15

Which type of ventilation is more functionally significant?

Answer 15

Alveolar

Question 16

How efficient is breathing at rest and why?

Answer 16

70%

Stale air in the dead space dilutes the fresh air and prevents the full volume of fresh air entering the alveoli

Question 17

What is more important in breathing - the rate or the depth?

Answer 17

Depth

Question 18

Partial pressure

Answer 18

The percentage of the gas multiplied by the pressure of the whole gaseous mixture which gives the gas’ partial pressure

Question 19

What 2 units can be used for pressure?

Answer 19

mmHg or kPa

Question 20

Why does the partial pressure increase with the concentration of gas molecules in the mixture?

Answer 20

All gases molecules exert the same pressure

Question 21

What vary with hypo and hyper ventilation?

Answer 21

PO2 and PCO2

Question 22

What is Hypoventilation? State what happens to PO2 and PCO2

Answer 22

Decreased alveolar ventilation
PO2 decreases to 30mmHg
PCO2 increases to 100mmHg

Question 23

What is hyperventilation? State what happens to PO2 and PCO2

Answer 23

Increased alveolar pressure
P02 increases to 120mmHg
PCO2 decreases to 20mmHg