Spirometry

Question 1

Total lung capacity

Answer 1

5. 7L - male

4. 2 L - female

Question 2

Normal breath

Answer 2

500ml of air moves in/out of lungs

Question 3

End of Expiration

Answer 3

2,200ml air in lungs

Question 4

End of max expiration

Answer 4

1200ml In males

1000ml females

Question 5

Why can’t lungs be maximally deflated?

Answer 5

Gas exchange occurs continuously: ensures gas content of blood relatively constant throughout respiratory cycle
Reduced WOV: less effort to inflate something that’s partly inflated

Question 6

What is lung capacity?

Answer 6

5.7 litres

Question 7

What are factors that may affect lung volumes?

Answer 7

Age - decrease lung volumes with age 
Gender - generally females < males
Anatomic build - tall people have large lung volumes 
Fitness - large lung volume
Smoking 
Respiratory disease 
High altitude

Question 8

TV

Answer 8

Tidal Volume

Question 9

IRV

Answer 9

Inspiratory reserve volume

Question 10

IC

Answer 10

Inspiratory capacity

Question 11

ERV

Answer 11

Expiratory reserve volume

Question 12

RV

Answer 12

Residual volume

Question 13

FRC

Answer 13

Functional residual volume

Question 14

VC

Answer 14

Vital capacity

Question 15

TLC

Answer 15

Total lung capacity

Question 16

TV

Answer 16

Volume of air entering/leaving lungs during a single breath

500ml

Question 17

IRV

Answer 17

Extra volume of air that can be maximally inspired
3000ml
Deceases with age

Question 18

IC

Answer 18

IRV + TV

3500ml

Question 19

ERV

Answer 19

Extra volume of air that can be maximally expired
1000ml
Decreases with age

Question 20

RV

Answer 20

Min volume of air remaining in the lungs after maximum expiration
1200ml
Increases with age

Question 21

FRC

Answer 21

ERV + RC

2200ml

Question 22

VC

Answer 22

TV + IRV + ERV

4500ml

Question 23

TLC

Answer 23

Maximum volume of air lungs can hold
VC + RV
5700ml

Question 24

Factors that affect WOB

Answer 24

1. Pulmonary compliance decreased
   (More work to expand the lungs)
2. Airway resistance increased (COPD)
   (More work to achieve greater pressure gradient to ensure adequate blood flow)
3. Elastic recoil decreased (emphysema)
   (Passive expiration inadequate to expel vol of air normally exhaled - abdominal muscle must work to empty lungs at rest)
4. Need for increased ventilation (exercise)
   (More work to achieve greater deeper and faster breaths

Question 25

Strenuous exercise

Answer 25

Amount of energy required for pulmonary ventilation to increase 25 fold Total EE: 15-20 fold Energy used for increased ventilation only represents 5% of total EE

Question 26

Disease state

Answer 26

Energy required for breathing to increase May be 30% of total EE at rest Effect: exercise ability decrease and breathing is exhausting

Question 27

What does a normal healthy lung have?

Answer 27

High compliance | Low airway resistance

Question 28

If compliance is abnormally high...

Answer 28

Lung emphysema Tissue destruction: alveoli to fuse form large air sacs Cause bronchioles to collapse more easily upon expiration

Question 29

If compliance is abnormally low...

Answer 29

Work of breathing is increased Lung fibrosis (scar tissue) Restrictive lung tissue

Question 30

What is radius of bronchi affects by?

Answer 30

Physical Chemical Neural factors

Question 31

What acts on airway smooth muscle

Answer 31

Chemical and neural factors

Question 32

Examples of dilators

Answer 32

Adrenalin C02 Peptide from sensory nerve

Question 33

Constrictors

Answer 33

Acetylcholine (parasympathetic - vagus - stimulated by irritiant receptors) Inflammatory mediators

Question 34

What is surface tension

Answer 34

Force at an air-fluid interface

Question 35

What causes surface tension?

Answer 35

Water molecules attract each other forming intermolecular bonds

Question 36

What determines lung compliance?

Answer 36

1. Resistance of tissues to stretch influenced by composition of extracellular matrix Too much - fibrosis (lung compliance) Not enough - emphysema (high compliance) 2. Resistance due to surface tension

Question 37

What does lung compliance measure?

Answer 37

Measure how easily lungs are expanded by a given change in pressure

Question 38

What does lung compliance determine?

Answer 38

Determine the amount of work that has to be done by respiratory muscles

Question 39

What does lung compliance define?

Answer 39

Stretchability of lung tissue

Question 40

traditional wet spirometer

Answer 40

Air-filled drum in water filled chamber Person breathes in/out through tube - air chamber Drum rises/falls during resp cycle > Spirograph

Question 41

Obstructive pathology

Answer 41

``` TLC - increased VC - decreased FEV1:FVC - decreases FRC - increased RV - increased ``` Difficult emptying lungs than filling Over-inflated air trapped FEV/VC (<80%)

Question 42

What is FEV1/VC an indication of?

Answer 42

Maximal airflow rate

Question 43

Restrictive pathology

Answer 43

``` Compliance of lung reduced Difficulty filling lungs E.g. pulmonary fibrosis, pneuomoniae, pulmonary oedema TLC - decreased VC - decreased ``` FEV/VC - >80%