Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Respiratory - Physiology > Physiology L2 - Respiratory Mechanics > Flashcards

Physiology L2 - Respiratory Mechanics Flashcards

1
Q

When do accessory muscles contract?

A

They only contract during forceful inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When do muscles of active expiration contract?

A

Only during active expiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When do the major muscles of inspiration contract?

A

Every inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When does passive expiration occur?

A

Relaxation after inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name the accessory muscles involved in inspiration?

A

Sternocleidomastoid

Scalenus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Name the muscles involved in active expiration?

A

Internal intercostal muscles

Abdominal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name the muscles/bones involved in inspiration and passive expiration?

A

Sternum
Ribs
External intercostal muscles
Diaphragm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the tidal volume (TV)?

A

The volume of air entering or leaving lungs during a single breath
(Average = 500ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the inspiratory reserve volume (IRV)?

A

Extra volume of air that can be maximally inspired over and above the typical resting tidal volume
(Average = 3000ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the inspiratory capacity (IC)?

A

Maximum volume of air that can be inspired at the end of a normal quiet expiration
(IC =IRV + TV)
(Average = 35000ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do you calculate inspiratory capacity (IC)?

A

IC = IRV + TV

IRV = Inspiratory reserve volume
TV = Tidal volume
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the expiratory reserve volume (ERV)?

A

Extra volume of air that can be actively expired by maximal contraction beyond the normal volume of air after a resting tidal volume
(Average = 1000ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does RV stand for in terms of respiration?

A

Residual volume. Minimum volume of air remaining in the lungs even after a maximal expiration (1200ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does FRC stand for in terms of respiration?

A

Functional residual capacity. Volume of air in lungs at end of normal passive expiration (FRC = ERV + RV) (2200ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does VC stand for in terms of respiration?

A

Vital capacity. Maximum volume of air that can be moved out during a single breath following a maximal inspiration (VC = IRV + TV + ERV)
(4500ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does TLC stand for in terms of respiration?

A

Total lung capacity. Maximum volume of air that the lungs can hold (TLC = VC + RV)
(5700ml)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is FEV1 or dynamic volume in terms of respiration?

A

Forces expiratory volume in one second.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is FVC in terms of respiration?

A

Forced vital capacity. It is the maximum volume that can be forcibly
Expelled from the lungs following a maximum inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is FEV1% in terms of respiration?

A

FEV1/FVC ratio.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What can be determined from plotting a volume time curve for dynamic lung volumes using spirometry?

A

FVC
FEV1
FEV1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What should normal FEV1% be?

A

> 75%

22
Q

What should asthmatic FEV1% be?

A

<75%

23
Q

Compare the normal and lung restrictive patterns on a volume time curve using FVC, FEV1 and FEV1%?

A

Curve: The curve starts later and the maximum is lower
FVC: decreases
FEV1: decreases
FEV1%: stays the same

24
Q

Compare normal and airway obstructed spirometry results using FVC, FEV1 and FEV1%?

A

FVC: low or normal
FEV1: low
FEV1%: low

25
Q

Compare normal and combination airway obstructed and restriction spirometry results using FVC, FEV1 and FEV1%?

A

FVC: low
FEV1: low
FEV1%: low

26
Q

What is airway resistance?

A

The resistance to airflow in the airways.

F = DeltaP / R

F = Flow 
P = Pressure
R = Resistance

Air flow (from atmosphere to lungs) is directly proportional to pressure gradient and inversely proportional to resistance.

27
Q

Describe normal airway resistance and pressure gradient?

A

Resistance to flow in the airway normally is very low and therefore air moves with a small pressure gradient

28
Q

What is the primary determination of airway resistance?

A

The radius of the conducting airway

29
Q

What causes bronchoconstriction?

A

Parasympathetic stimulation

30
Q

What causes bornchodilation?

A

Sympathetic stimulation

31
Q

What can cause significant resistance to airflow?

A

Disease states such as COPD or asthma

32
Q

What is more difficult (has more resistance) expiration or inspiration?

A

Expiration

33
Q

What pulls open the airways during inspiration?

A

The expanding thorax

34
Q

What effects does dynamic airway compression have on patents with airway obstruction?

A

Makes active expiration more difficult

35
Q

How does dynamic airway compression cause active expiration to be more difficult in patients with airway obstruction?

A

The rising pleural pressure during active expiration compresses the alveoli and airway. Pressure applied to alveolus helps
pushes air out of lungs however pressure applied to the airway is not desirable as it compresses it.

36
Q

Does dynamic airway compression cause any problems in normal people and why?

A

No. The increased airway resistance causes an increase in airway pressure upstream (in the alveoli). This helps open the airways by increasing the the driving pressure between the alveolus and airway (i.e. the pressure downstream)

37
Q

What happens with dynamic airway compression during active expiration in patients with airway obstructions?

A

If there is an obstruction (e.g. asthma or COPD), the driving pressure between the alveolus and airway is lost over the obstructed segment. This causes a fall in airway pressure along the airway downstream resulting in airway compression by the rising pleural pressure during active expiration

38
Q

What type of airways are more likely to collapse?

A

Diseased airways. The problem becomes worse if the patient also have decreased elastic recoil of lungs (e.g. a patient with emphysema and obstructed airway caused by COPD) The airway is unable to oppose the intrapleural pressure which means it has a tendency to collapse.

39
Q

What does a peak flow meter do?

A

Gives an estimate of peak flow rate which asses airway function.

40
Q

How is a peak flow meter used?

A

It is measured by the patient giving a short sharp below into the peak flow meter. The best of three attempts is usually taken.

41
Q

How does peak flow rate vary?

A

The peak flow rate in normal adults vary with age and height

42
Q

What is pulmonary compliance?

A

During inspiration the lungs are stretched. The compliance is the measure of efforts that has to go into stretching or dis-stretching the lungs i.e. how easy it is for the lung to stretch

Volume change per unit of pressure change across the lungs

43
Q

Are lungs which require more work to produce a given degree of inflation less or more compliant?

A

Less

44
Q

What conditions decrease compliance?

A 
Pulmonary fibrosis
Pulmonary oedema
Lung collapse
Pneumonia
Absence of surfactant
45
Q

What does decreased pulmonary compliance mean?

A

greater change in pressure is needed to produce a given change in volume (i.e. lungs are stiffer). This causes shortness of breath especially on exertion

46
Q

What does decreased pulmonary compliance cause?

A

This causes shortness of breath especially on exertion. It also may cause restrictive pattern of lung volumes in spirometry

47
Q

When might pulmonary compliance be increased and give an example?

A
  1. Compliance may become abnormally increased if the elastic recoil of the lungs is lost i.e. emphysema: patients have to work harder to get the air out of the lungs – hyperinflation of lungs.
  2. When dynamic airway obstruction is aggravated in patents with obstructed airways i.e. COPD or emphysema
  3. Compliance also increases with age.
48
Q

What is meant by work of breathing?

A

The work of breathing is the work required by the respiratory muscles in order to overcome the mechanical impedance to respiration caused by the lung, chest wall and abdominal contents during breathing. It is the sum of the work required to overcome both elastic properties and flow resistance

49
Q

What percentage of total energy expenditure is used for quiet breathing?

A

3%

50
Q

What is meant by the fact that lungs operate at “half full”?

A

The functional residual capacity is about 2200ml while the total capacity is about 5700ml

51
Q

In what situation is the work or breathing increase?

A
  1. When pulmonary compliance is decreased
    2 .When airway resistance is increased
  2. When elastic recoil is decreased
    4 .When there is a need for increased ventilation

Respiratory - Physiology (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions