Physiology 2 (Week 1)

Question 1

What is tidal volume?

Answer 1

The volume of air entering or leaving the lungs during a single breath

Question 2

What is the average tidal volume in a healthy person?

Answer 2

500ml

Question 3

What is inspiratory reserve volume?

Answer 3

The maximum volume of air that can be inspired over and above the tidal volume

Question 4

What is the average inspiratory reserve volume in a healthy person?

Answer 4

3000ml

Question 5

What is inspiratory capacity?

Answer 5

The maximum volume of air that can be inspired after a normal expiration

IC = Inspiratory reserve volume + Tidal volume

Question 6

What is expiratory reserve volume?

Answer 6

The extra volume of air that can be actively expired after the normal, tidal volume

Question 7

What is the average expiratory reserve volume in a healthy person?

Answer 7

1000ml

Question 8

What is the average inspiratory capacity in a healthy person?

Answer 8

3500ml

Question 9

What is residual volume?

Answer 9

The minimum volume of air remaining in the lungs even after a maximal expiration

Question 10

What is the average residual volume in a healthy person’s lungs?

Answer 10

1200ml

Question 11

What is functional residual capacity?

Answer 11

The volume of air in the lungs after a normal passive expiration

FRC = Expiratory reserve volume + Residual volume

Question 12

What is the average functional residual capacity in a healthy person?

Answer 12

2200ml

Question 13

What is vital capacity?

Answer 13

The maximum volume of air that can be moved out during a single breath following a maximal inspiration

VC = Inspiratory reserve volume + Tidal volume + Expiratory reserve volume

Question 14

What is the average vital capacity in a healthy person?

Answer 14

4500ml

Question 15

What is total lung capacity?

Answer 15

The maximum volume of air that the lungs can hold

Question 16

What is the average total lung capacity in a healthy person?

Answer 16

5700ml

Question 17

Give a word equation for total lung capacity.

Answer 17

Total lung capacity = Vital capacity + Residual volume

Question 18

What happens to the residual volume when elastic recoil of the lungs is lost?

Answer 18

Residual volume increases

Question 19

Give an example of a disease which reduces elastic recoil of the lungs.

Answer 19

Emphysema

Question 20

Dynamic lung volumes are useful in the diagnosis of _____ and ____ lung disease.

Answer 20

obstructive , restrictive

Question 21

What is Forced Vital Capacity (FVC)?

Answer 21

The maximum volume of air which can be forcibly expelled from the lungs following a maximal inspiration

Question 22

What is FEV1?

Answer 22

Forced Expiratory Volume in 1s - the volume of air which is expelled during the first second of an FVC determination.

Question 23

What is the FEV1/FVC ratio?

Answer 23

The proportion of the forced vital capacity which can be expired in the first second of an FVC determination

Question 24

What range of FEV1/FVC ratio values is normal for a healthy person?

Answer 24

> 70%

Question 25

In obstructive lung disease, the FEV1/FVC ratio is usually...

Answer 25

< 70%

Question 26

Why is the FEV1/FVC ratio reduced in obstructive lung disease?

Answer 26

It takes long for the lungs to expire the same volume of air

Question 27

Why, in restrictive lung disease, does the FEV1/FVC ratio still have a value > 70%?

Answer 27

Both FEV1 and FVC are reduced - ratio remains the same.

Question 28

Give an equation for flow rate of air in the lungs.

Answer 28

F = deltaP / R i.e Flow = Change in pressure / Resistance

Question 29

What is the primary determinant of airway resistance?

Answer 29

Radius of airway (r)

Question 30

Parasympathetic stimulation causes _____.

Answer 30

bronchoconstriction

Question 31

Sympathetic stimulation causes ____.

Answer 31

bronchodilatation

Question 32

Which division of the nervous system causes bronchoconstriction?

Answer 32

Parasympathetic division

Question 33

Which division of the nervous system causes bronchodilatation?

Answer 33

Sympathetic division

Question 34

Name two diseases which significantly increase airway resistance.

Answer 34

COPD | Asthma

Question 35

With regard to inspiration and expiration: _____ is more difficult than _____.

Answer 35

Expiration , inspiration

Question 36

_____ is difficult for patients with airway obstruction.

Answer 36

Expiration

Question 37

During expiration, intrapleural pressure _____.

Answer 37

increases

Question 38

What is a consequence of increasing intrapleural pressure during expiration in patients with airway obstructions?

Answer 38

Compression of the airways and alveoli

Question 39

In normal people, increased airway resistance caused by compression downstream results in...

Answer 39

Increased airway pressure upstream | Opening of the airway by driving pressure

Question 40

In people with airway obstruction, increased airway resistance caused by compression downstream results in...

Answer 40

Increased airway pressure upstream Driving pressure is lost over the obstructed segment Decrease in downstream pressure Airway collapse

Question 41

What is the name of the process in which airways and alveoli are compressed by the pleura, caused by variable pressures during inspiration and expiration?

Answer 41

Dynamic airway compression

Question 42

What exacerbates dynamic airway compression?

Answer 42

Decreased elastic recoil of the lungs (e.g in emphysema, COPD)

Question 43

A peak flow meter gives an estimate of ___ ___ ___.

Answer 43

peak flow rate

Question 44

What does peak flow rate give an indication of?

Answer 44

Airway function

Question 45

How is peak flow rate measured during a consultation with a patient?

Answer 45

1. Patient a short, sharp blow into peak flow meter | 2. Best of three attempts taken as peak flow rate

Question 46

During inspiration, the lungs are _____.

Answer 46

stretched

Question 47

What is a colloquial definition of pulmonary compliance?

Answer 47

The effort that goes into stretching the lungs

Question 48

What is the scientific definition of pulmonary compliance?

Answer 48

Volume change per unit of pressure change across the lungs

Question 49

The less compliant the lungs are, the more ___ required to produce sufficient inflation.

Answer 49

work

Question 50

Name two factors which reduce pulmonary compliance.

Answer 50

``` Pulmonary fibrosis Pulmonary oedema Lung collapse Pneumonia Lack of pulmonary surfactant ```

Question 51

Why do the lungs feel stiff in patients with reduced pulmonary compliance?

Answer 51

A greater change in pressure is required to produce the same change in volume

Question 52

What sensation do patients with reduced pulmonary compliance feel during exertion?

Answer 52

Shortness of breath

Question 53

In spirometry, reduced pulmonary compliance presents what type of lung disease?

Answer 53

Restrictive lung disease

Question 54

When the elastic recoil of the lungs is lost, pulmonary compliance _____.

Answer 54

increases

Question 55

Name a disease which can result in increased pulmonary compliance.

Answer 55

Emphysema

Question 56

What is a sign associated with increased pulmonary compliance?

Answer 56

Hyperinflation of the lungs

Question 57

Pulmonary compliance increases with ___.

Answer 57

age

Question 58

What is the name given to the outward appearance of effort going into breathing?

Answer 58

Work of breathing

Question 59

Roughly what percentage of energy expenditure goes into the work of breathing?

Answer 59

3%

Question 60

How full are the lungs normally?

Answer 60

Around half-full

Question 61

Name two cases in which the work of breathing would increase.

Answer 61

1. Pulmonary compliance decreases 2. Airway resistance increases 3. Elastic recoil decreases 4. When there is a need for increased ventilation