General Principles of Lung Physiology

Question 1

Define tidal volume

Answer 1

Volume that enters and leaves the lung with each breath

Quiet breathing

Question 2

What is the average tidal volume (L)

Answer 2

0.5

Question 3

What does tidal volume change with

Answer 3

Pattern of breathing e.g. shallow breaths vs deep breaths

Increases with pregnancy

Question 4

Define inspiratory reserve volume

Answer 4

Extra volume that can be inspired above tidal volume, from normal to quiet expiration to maximum inspiration

Question 5

What is the average inspiratory volume (L)

Answer 5

2.5

Question 6

What does inspiratory volume rely on

Answer 6

Muscle strength
Lung compliance
Normal starting point

Question 7

Define expiratory reserve volume

Answer 7

Extra volume that can be expired below tidal volume, from normal quiet expiration to maximum expiration

Question 8

What is the average volume of expiratory reserve volume (L)

Answer 8

1.5 L

Question 9

What does expiratory reserve volume rely on

Answer 9

Muscle strength
Low airway resistance

Question 10

What reduces expiratory reserve volume

Answer 10

Pregnancy
Obesity
Severe obstruction

Question 11

Define residual volume/reserve volume

Answer 11

Volume remaining after maximum expiration

Question 12

What is the average volume of residual volume/reserve volume (L)

Answer 12

1.5

Question 13

What can residual volume/reserve volume not be measured by

Answer 13

Spirometry

Question 14

Define capacities

Answer 14

Composed of two of more lung volumes

These are fixed and do not change with patterns of breathing

Question 15

Define vital capacity/forced vital capacity

Answer 15

Volume that can be exhaled after maximum inspiration

Maximum inspiration to maximum expiration

Question 16

How would you calculate vital capacity/forced vital capacity

Answer 16

Inspiratory reserve volume +

Tidal volume +

Expiratory reserve volume

Question 17

What is the average volume of vital capacity/forced vital capacity

Answer 17

4.5 L

Question 18

Define functional residual capacity

Answer 18

Volume remaining after quiet expiration

Question 19

How do you calculate functional residual capacity

Answer 19

Expiratory reserve volume +

Residual volume

Question 20

What is the average volume of functional residual capacity

Answer 20

3 L

Question 21

What is average functional residual capacity affected by

Answer 21

Height (has the greatest influence)
Gender
Posture
Changes in lung compliance

Question 22

Define inspiratory capacity

Answer 22

Volume breathed in from quiet expiration to maximum inspiration

Question 23

How would you calculate inspiratory capacity

Answer 23

Tidal Volume +

Inspiratory reserve volume

Question 24

What is the average volume of inspiratory capacity (L)

Answer 24

3L

Question 25

Define total lung capacity

Answer 25

Volume of air in lungs after maximum inspiration

Question 26

How would you calculate total lung capacity

Answer 26

Sum of all volumes

Question 27

Define restriction

Answer 27

< 80% of predicted total lung capacity

Question 28

What is the average volume of total lung capacity

Answer 28

6 L

Question 29

Define hyperinflation

Answer 29

> 120% of predicted total lung capacity