Measures of lung physiology

Question 1

Inspiratory reserve volume definition

Answer 1

amount of air in excess tidal inspiratory that can be inhaled wth maximum effort

Question 2

what does IRV stand for

Answer 2

inspiratory reserve volume

Question 3

what is the average value of IRV

Answer 3

3l

Question 4

Expiratory reserve volume definition

Answer 4

amount of air in excess tidal expiration that can be exhaled with maximum effort

Question 5

what does ERV stand for

Answer 5

expiratory reserve volume

Question 6

what is the average value of ERV

Answer 6

1.2L

Question 7

residual volume definition

Answer 7

amount of air remaining in lungs after maximum expiration

Question 8

what does RV stand for

Answer 8

residual volume

Question 9

what is the average value of RV

Answer 9

1.2L

Question 10

what is the purpose of RV

Answer 10

keeps alveoli inflated between breaths and mixes with fresh air on next inspiration

Question 11

vital capacity definition

Answer 11

amount of air that can exhaled with maximum effort after maximum inspiration

Question 12

what does VC stand for

Answer 12

vital capacity

Question 13

what is the average value of VC

Answer 13

4.7L

Question 14

what is useful about VC

Answer 14

assess strength of thoracic muscles as well as pulmonary function

Question 15

what is an equation for VC

Answer 15

ERV + TV + IRV

Question 16

functional residual capacity definition

Answer 16

amount of air remaining in lungs after normal tidal expiration

Question 17

what is FRC

Answer 17

functional residual capacity

Question 18

what is the average value of FRC

Answer 18

2.4L

Question 19

what is an equation for FRC

Answer 19

FRC = RV + ERV

Question 20

inspiratory capacity definition

Answer 20

maximum amount of air that can be inhaled after a normal tidal expiration

Question 21

what is IC

Answer 21

inspiratory capacity

Question 22

what is an average value for IC

Answer 22

3.5L

Question 23

what is an equation for IC

Answer 23

IC = TV + IRV

Question 24

total lung capacity equation

Answer 24

maximum amount of air the lungs can contain

Question 25

what does TLC stand for

Answer 25

total lung capacity

Question 26

what is an average value for TLC

Answer 26

5.9L

Question 27

what is an equation for TLC

Answer 27

TLC = RV + VC

Question 28

tidal volume definition

Answer 28

amount of air inhaled or exhaled in 1 breath

Question 29

what does TV stand for

Answer 29

tidal volume

Question 30

what is an average TV

Answer 30

500ml

Question 31

what is an equation for pressure

Answer 31

pressure = flow x resistance

Question 32

what is Poiseuilles law

Answer 32

airways resistance is proportional to 4th power of radius

Question 33

describe a flow volume curve

Answer 33

flow greatest at start of expiration and declines linearly with volume

Question 34

what is carbon monoxide single breath transfer factor used for

Answer 34

good measure of gas exchange in alveolar capillary

Question 35

why is CO used to estimate DLco

Answer 35

has high affinity for binding to Hb

Question 36

what is the exhaled nitric oxide test

Answer 36

indirect measure of airway inflammation

Question 37

what does total blody plethysmography measure

Answer 37

total lung capacity including air trapped in bullae

Question 38

what does gas dilution measure

Answer 38

all air in lungs that communicates with airways - doesn't measure air in non-communicating bullae

Question 39

what gas is used in gas dilution

Answer 39

helium

Question 40

what is compliance (in regard to lungs)

Answer 40

change in volume per unit change in pressure gradient between pleura and alveoli (transpulmonary pressure)

Question 41

what does a larger lung compliance mean

Answer 41

lungs are more readily expanded

Question 42

what determines lung compliance

Answer 42

Stretchability if lung tissue and surface tension of air-water interfaces in alveoli

Question 43

what is FEV1

Answer 43

forced expiration volume in 1st second of expiration OR volume of air expelled after 1 second of forced expiration

Question 44

what is a value of FEV1

Answer 44

80% of VC in health

Question 45

what does FVC stand for

Answer 45

forced vital capacity

Question 46

FVC definition

Answer 46

volume of air that can be forcefully exhaled with a maximal inspiration

Question 47

what does FVC measure

Answer 47

lung size

Question 48

what does a low value FVC show

Answer 48

restriction

Question 49

what is peak expiratory flow

Answer 49

single measure of highest flow during expiration

Question 50

what shows airway obstruction

Answer 50

FEV1/ FVC ratio < 0.70

Question 51

what shows airway restriction

Answer 51

low value FVC (< 80%)

Question 52

why does airway restriction have low value FVC

Answer 52

reduced compliance of lungs so FEV1 and FVC reduced, but ratio remains the same

Question 53

describe the signs of asthma

Answer 53

obstruction PEF variation reduced mix-expiratory flow good response to treatment

Question 54

describe the signs of COPD

Answer 54

``` obstruction lack of significant PEF variation reduced mid-expiratory flow partial/ poor response to treatment low DLco because capillary interface destroyed so transfer problems ```

Question 55

describe the signs of pulmonary fibrosis

Answer 55

restriction lack of PEF variation reduced mid-expiratory volume