Brainscape's Knowledge GenomeTM

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


See full index

Cardiopulmonary Exam 3 > 5A - Resp. Mechanics and Pathophys of Asthma > Flashcards

5A - Resp. Mechanics and Pathophys of Asthma Flashcards

1
Q

5a4. What are the pressures involved with breathing?

A

Atmospheric pressure
Intra-alveolar pressure (intrapulmonary)
Intrapleural pressure
Transpulmonary pressure (i.e. the difference between intra-alveolar and intrapleural pressure)

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

5a5. What is intrapleural pressure?

A

The pressure that pulls the lungs (visceral pleura) away from the chest wall (parietal pleura) and cause the lungs to collapse

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

5a5. What generates negative intrapleural pressure?

A

Two forces in the thoracic cavity

  1. The lungs’ natural tendency to recoil. (The lungs always assume the smallest size possible because of their elasticity.)
  2. The surface tension of the alveolar fluid. (The surface tension of the alveolar fluid constantly acts to draw the alveoli to their smallest possible dimension.)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

5a5. The force to collapse the lungs is opposed by what force?

A

The natural elasticity of the chest wall, a force that tends to pull the thorax outward and to enlarge the lungs

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

5a6. In a healthy person, which side of the intrapleural forces wins out ultimately?

A

Neither in a healthy person, because of the strong adhesive force between the parietal and visceral pleura.

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

5a6. What is the net result of the dynamic interplay between the intrapleural forces?

A

A negative P(ip). The pleura may slide from side to side easily, but they remain close to each other and separately them requires extreme force.

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

5a7. What is transpulmonary pressure?

A

The difference between the intrapulmonary and intrapleural pressures (Ppul - Pip).

It keeps the air spaces of the lungs open (or keeps it from closing).

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

5a7. Does lung size increase or decrease with high transpulmonary pressure?

A

Lung size will increase

The greater the transpulmonary pressure, the larger the lungs

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

What is the equation for Boyle’s Law?

A

P1V1 = P2V2

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

5c9. Respiratory Cycle

What is the alveolar pressure equal to at rest (before inspiration begins)?

A

Alveolar pressure equals atmospheric pressure

Because lung pressures are expressed relative to atmospheric pressure, alveolar pressure is said to be zero.

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

5c9. Respiratory Cycle

What is intrapleural pressure at rest (before inspiration begins)?

A

Negative

The opposing forces of the lungs trying to collapse and the chest wall trying to expand, creating a negative pressure in the intrapleural space between them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

5c9. Respiratory Cycle

What is lung volume at rest (before inspiration begins)?

A

Lung volume is the FRC (Functional residual capacity)

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

5c10. Respiratory Cycle - During inspiration
- The inspiratory muscles do what?
- This cause what?

A

Inspiratory muscles contract

This causes the volume of the thorax to increase

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

5c11. Respiratory Cycle - During inspiration

- Intrapleural pressure becomes?

A

Intrapleural becomes more negative

Because lung volume increases, the elastic recoil strength of the lungs also increases. As a result, intrapleural pressure becomes even more negative than it was at rest.

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

5c11. Respiratory Cycle - During inspiration

- Lung volume?

A

Lung volume increases by one TV (tidal volume)

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

5c12. Respiratory Cycle - During expiration
- Alveolar pressure?
- Why?
- What happens to air flow?

A

Alveolar pressure becomes greater than atmospheric pressure

  • Alveolar pressure becomes greater because alveolar gas is compressed by the elastic forces of the lung
  • Air flow flows out of lungs due to alveolar pressure > atmospheric pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

5c13. Respiratory Cycle - During expiration

- Intrapleural pressure?

A

Intrapleural pressure returns to its resting value during a normal (passive) expiration

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

5c13. Respiratory Cycle - During expiration

- What happens during intrapleural pressure during a “forced expiration”?

A

Intrapleural pressure goes from negative to resting value to positive. This positive intrapleural pressure compresses the airways and actually makes expiration more difficult

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

5c13. Respiratory Cycle - During expiration

- Lung volume?

A

Lung volume returns to FRC (Functional residual capacity)

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

5c14. In addition to the inspiratory muscles consuming energy to enlarge the thorax, energy must also be used to overcome what factors?

A

Various factors that hinder air passage and pulmonary ventilation

  • Airway resistance
  • Alveolar surface tension
  • Lung compliance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What muscle is airway resistance directly related to?

A

Contraction and relaxation of bronchial smooth muscle

  • Airway resistance is changed by altering the radius of their airways
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which factors increase airway resistance?

A

Contraction of the bronchial smooth muscles

  • Parasympathetic stimulation
  • Muscarinic agonists
  • Iritants
  • Slow-reacting substances of anaphylaxis (asthma)

They constrict the airways, decrease radius, and increase airway resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which factors decrease airway resistance?

A

Relaxation of the bronchial smooth muscles

  • Sympathetic stimulation
  • Sympathetic agonists

They dilate the airways via B-2 receptors, increase radius, and decrease the resistance to airflow

24
Q

5c16. What does alveolar surface tension result from?

A

Results from the attractive forces between liquid molecules lining the alveoli.

25
Q

5c16. What is Laplace’s Law?

A

P = 2T / R

P = Collapsing pressure on alveolus or Pressure required to keep alveolus open
T = Surface tension
R = Radius of the alveolus
26
Q

5c16. Which of the factors that hinder air passage and pulmonary ventilation is related to Laplace’s Law?

A

Alveolar surface tension
- it results from the attractive forces between liquid molecules lining the alveoli.

These forces create a collapsing pressure that is directly proportional to surface tension and inversely proportional to alveolar radius.

P = 2T / R

27
Q

5c17. What is the purpose of pulmonary surfactant and what cells make it?

A

To prevent the collapse of alveoli within the lung

Made by type 2 alveolar cells and coasts the inside of each alveoli

28
Q

5c17. What does pulmonary surfactent consist of?

A

Phospholipid DPPC
Other lipids
Proteins
Carbohydrates

29
Q

5c17. Why are phospholipids the major component of surfactent?

A

Its amphipathic properties

30
Q

5c18. What is the function of surfactent?

A

To lower surface tension and subsequently reduce the tendency of the alveoli to collapse completely

31
Q

5c18. What age demographic primarily has issues with no surfactent?

A

Pre-mature babes (surfactent isn’t made until around the 7th month or later)

32
Q

5c19. Alveolar surface tension - large alveoli
- High or low collapsing pressure
- Hard or easy to keep open
- Large or small radii

A

Low collapsing pressure
Easy to keep open
Large radii

33
Q

5c19. Alveolar surface tension - small alveoli
- High or low collapsing pressure
- Hard or easy to keep open
- Large or small radii

A

High collapsing pressure
Difficult to keep open
Small radii

34
Q

5c19. What is atelectasis?

A

The tendency for small alveoli to collapse in the absence of pulmonary surfactent

35
Q

5c20. What does compliance describe?

What is compliance inversely related to?

A

Compliance describes the distensibility (stretchability) of the lungs.

Compliance is inversely related to “stiffness”

36
Q

5c20. What is the mathematical definition of compliance?

A

C = V / P

Compliance is the change in volume for a given change in pressure

37
Q

5c20. Describe compliance and lung distensibility at the middle range of pressures

A

Compliance is greatest and the lungs are most distensible at the middle range

C = V / P

38
Q

5c20. Describe compliance and lung distensibility at high expanding pressures

A

Compliance is lowest and the lungs are least distensible

(On the graph, the curve flattens)

C = V / P

39
Q

5c20. Under what conditions does it take more energy to breath?
- In relation to lung distensibility
- In relation to compliance

A

The stiff the lungs (low distensibility) and low compliance, the more energy it takes to breathe

40
Q

5c21. What triggers an asthma attack?

A

It begins when an allergen is inhaled. The allergen binds to IgE antibodies on mast cells in the lungs.

41
Q

5c21. When an allergen binds to IgE antibodies on mast cells in the lungs, what is triggered?

A

Binding triggers exocytosis of the mast cells with the release of:

  • Histamine
  • Leukotrienes
42
Q

5c22. What do histamines and leukotrienes do to smooth muscle cells of the bronchi?

What phase of asthma is this?

A

Smooth muscle cells of the bronchi contract, narrowing the lumen of the bronchi - typically within 1 hour of exposure to the antigen

Known as the “early phase/reaction”

43
Q

5c22. What do histamines and leukotrienes attract and produce?

What phase of asthma is this?

A

Attract an accumulation of inflammatory cells - especially eosinophils

The production of mucus

Known as the late phase/reaction (4-5 hours after exposure to antigen)

44
Q

5c22. What can occur with repeated late phase/reactions?

A

Repeated attacks can cause damage to the lining of the bronchi

(Accumulation of inflammatory cells - eosinophils - and the production of mucus)

45
Q

5c23. What is “probably” the genetic component associated with asthma?

A

For reasons that are not yet understood, some people have a predisposition to respond to antigens by making antibodies of the IgE class.

46
Q

5c23. Asthma typically begins as an allergic response, but in time can be triggered by what?

A

Non-specific factors like:

- Cold air, exercise, and tobacco smoke

47
Q

5c24. What are the four things that asthma is physiologically and pathologically characterized by?

A
  1. Increased responsiveness of the trachea and bronchi (to various stimuli/triggers)
  2. Bronchoconstriction (airway smooth muscle constriction)
  3. Inflammation (Mucosal thickening from edema and cellular infiltration)
  4. Thick plugs of mucus collection (in the airways)
48
Q

What are the symptoms of obstructive lung disease?

  • Breath duration?
  • Exhaled air speed?
  • Air levels in the lungs?
A

Shortness of breath due to difficulty exhaling all the air from the lungs.

Due to lung damage/increased airway resistance, exhaled air comes out more slowly than normal.

At the end of a full respiration, an abnormally high amount of air may still linger in the lungs.

49
Q

What are the most common causes of obstructive lung disease?

A
  1. COPD - chronic obstructive pulmonary disease (includes emphysema and chronic bronchitis)
  2. Asthma
50
Q

5c26. What is restrictive lung disease?

A

Patients diagnosed with restrictive lung disease cannot fully fill their lungs with air. Their lungs are restricted from fully expanding.

51
Q

5c26. Restrictive lung disease generally results from what type of condition?

A

Results from a condition causing stiffness in the lungs themselves. In most cases, stiffness of the chest wall, weak muscles, or damaged nerves may cause the restriction in lung expansion.

52
Q

5c28. What are some examples of conditions that cause restrictive lung disease?

A
  1. Interstitial lung disease such as idiopathic pulmonary fibrosis
  2. Obesity
  3. Neuromuscular diseas, such as muscular dystrophy or amyotrophic lateral sclerosis (Lou Gehrig’s Disease)
53
Q

5c27. What is forced expiratory volume (FEV)?

A

The percentage of the vital capacity that can be exhaled in a given time interval.

A way to clincally assess pulmonary function via analysis of airflow. Airflow can be measured via rapid exhalation into a spirometer.

54
Q

5c27. What valve of FEV is termed FEV 1.0?

A

75-85% of vital capacity expelled in 1.0 seconds (for a healthy adult)

55
Q

5c28. What general FEV pattern for obstructive diseases?

What’s an example of an obstructive airway disease?

A

The FEV 1.0 is reduced much more than the FVC (forced vital capacity), giving a low FEV 1.0 / FEV%.

Asthma is an example

56
Q

5c28. What general FEV pattern for restrictive diseases?

What’s an example of restrictive airway disease?

A

Both FEV and FVC (forced vital capacity) are reduced, but characteristically the FEV 1.0 / FVC% is normal or increased.

Pulmonary fibrosis

57
Q

5c28. Frequently, what type of FEV patterns seen in patients?

A

Mixed restrictive and obstructive patterns

Cardiopulmonary Exam 3 (4 decks)

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