Lung Volumes and Measurements

Question 1

What is spirometry?

Answer 1

A test that assesses lung function in health and disease

Question 2

What does P stand for in spirometry?

Answer 2

Gas pressure

Question 3

What does Vo stand for in spirometry?

Answer 3

Gas volume

Question 4

What does V stand for in spirometry?

Answer 4

Gas flow

Question 5

What does the subscript I stand for in spirometry?

Answer 5

Inspired gas

Question 6

What does the subscript E stand for in spirometry?

Answer 6

Expired gas

Question 7

What does the subscript A stand for in spirometry?

Answer 7

Alveolar

Question 8

What does the subscript B stand for in spirometry?

Answer 8

Barometric

Question 9

What does the subscript a stand for in spirometry?

Answer 9

arterial

Question 10

What does the subscript v stand for in spirometry?

Answer 10

Venous

Question 11

What is tidal volume(Vt)?

Answer 11

Air inhaled and exhaled during quiet respiration

Question 12

What is the typical tidal volume?

Answer 12

~500 ml

Question 13

What is the inspiratory reserved volume(IRV)?

Answer 13

Max amount that can be inspired after quiet inspiration

Question 14

What is the typical figure for IRV?

Answer 14

~3.1L

Question 15

What is the expiratory reserve volume?

Answer 15

Max amount that can be expired after normal expiration

Question 16

What is the typical ERV?

Answer 16

~1.2L

Question 17

What is the residual volume?

Answer 17

Air left in lungs at the end of max expiration

Question 18

What is the typical RV?

Answer 18

~1.2L

Question 19

What is the inspiratory Capacity?

Answer 19

Mass that can be inspired after normal tidal expiration

Question 20

What is the typical IC?

Answer 20

~3.6L

Question 21

How does one calculate the inspiratory capacity of an individual?

Answer 21

Tidal volume + Inspiratory reserve volume

Question 22

What is the functional residual capacity?

Answer 22

Amount left in the lungs following normal tidal expiration

Question 23

What is the typical FRC?

Answer 23

~2.4L

Question 24

How does one calculate their functional residual capacity?

Answer 24

ERV + RV

Question 25

What is the vital capacity?

Answer 25

Volume that can be expired after a max inspiration

Question 26

What is the typical VC?

Answer 26

~4.8L

Question 27

How does one calculate the vital capacity?

Answer 27

Tidal volume + Inspiratory reserve volume + Expiratory reserve volume

Question 28

What is the total lung capacity?

Answer 28

Amount in lungs following max inspiration

Question 29

How does one calculate the total lung capacity?

Answer 29

IRV + Tidal volume + ERV + RV

Question 30

What is the hardest figure to calculate in spirometry?

Answer 30

Residual volume

Question 31

What is peak inspiratory flow?

Answer 31

Max flow rate obtained during inspiratory manouver

Question 32

What is peak expiratory flow?

Answer 32

Max flow rate forcefully breathed out of lung

Question 33

What is the forced vital capacity?

Answer 33

Forced expiration started from full inspiration, ending at complete expiration

Question 34

What is the forced expiratory volume in one second?

Answer 34

Volume of air forcefully breathed out of lungs in 1 second starting from a position of full inspiration

Question 35

What is the % FVC expired in one second used to diagnose?

Answer 35

Airway obstruction

Question 36

What factors affect a spirometry result?

Answer 36

Position of testing (Supine/Standing) Ethnicity Size Sex Age Muscular/aerobic training

Question 37

What does the forced residual capacity measure?

Answer 37

Index of elastic recoil Weakness of thoracic muscles Presence of obstruction

Question 38

How do we calculate minute ventilation(V̇E)?

Answer 38

Tidal volume x frequency

Question 39

How do we calculate alveolar ventilation?

Answer 39

(V tidal - V Deadspace) * Frequency

Question 40

What is alveolar ventilation inversely proportional to?

Answer 40

The partial arterial pressure of CO2