Section 5 Lecture 3 Flashcards Preview

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Flashcards in Section 5 Lecture 3 Deck (72):
1

True or False? Inspiration is active at all lungs volumes.

F. not for FRC

2

When does expiration because active?

exercise, cough, vomiting, ling disease that increases airway resistance, speaking and singing

3

True or False? The more a muscle stretches the more force it can generate.

F. more stretch = less force

4

What results if the recoil > chest wall force?

FRC decreases

5

What results if the muscles of contraction are weak/

FRC decreases (why? I would think it would increase)

6

an instrument for measuring changes in volume in lungs:

plethysmograph

7

What can lead to premature airway closure?

plethysmograph > helium (?)

8

Transpulmonary pressure is aka:

transmural pressure

9

Transpulmonary pressure =

alveolar - pleural pressures

10

P (w) is:

Transmural pressure across the chest wall

11

P (w) =

pleural - barometric pressure

12

P (rs) (respiratory system) =

transmural pressure surrounding lungs + transmural pressure across chest wall OR alvelor - barometric pressure

13

What does a spirometer tracing show?

lung volumes and capacities

14

FRC =

residual volume + ERV

15

Vital capacity =

ERV + Tidal volume + IRV

16

Inspiratory capacity =

Tidal volume + IRV

17

Avg tidal volume:

500 mL

18

Avg IRV:

3000 mL

19

Avg ERV:

1100 mL

20

Avg vital capacity:

4600 mL

21

Pulmonary volumes, men vs. women:

5800 vs. 4200 (the graph was for a man)

22

Primary determinants of lung volume:

sex, age, height (20% variability)

23

Avg RV/ TLC ratio:

25%

24

Elevated RV/ TLC ratio secondary to RV elevation:

obstructive pulmonary diseases (chronic bronchitis)

25

Elevated RV/ TLC ratio secondary to TLC decrease:

restrictive lung diseases (pulmonary fibrosis)

26

Factors affecting the RV/ TLC ration:

elastic recoil of lung, compliance, muscle strength of inspiratory muscles, recoil of the chest wall

27

How is FRC affected if the chest wall muscles are weak?

FRC decreases, lung elastic recoil > chest wall muscle force

28

How is FRC affected if there is an airway obstruction?

FRC increases (premature airway closure)

29

How are measurements of RV and TLC taken?

body plethysmography or helium dilution

30

C(1) X V(1) =

C(2) X (V(1) + V(2)

31

P(1) (this is pressure before inspiration) X V (V is FRC) =

P(2) (V - delta v) (P(2) is pressure after inspiration)

32

True or False? Less than half of the FVC is exhaled during FEV(1).

F More than half, about 3/4

33

Average FEV1/FVC ratio:

3L/4L = 75%

34

What factors decrease FEV(1) /FVC ratio?

decrease muscle strength, increases airways resistance, increases lungs compliance

35

What causes the increase in resistance in emphysema?

smooth muscle constriction and mucus plugging of the airways

36

Which lungs volumes increases and which decrease in emphysema?

increase: V, FRC, and TLC, decrease: VC and FEV

37

FEV(1)/FVC ratio in patient with emphysema

1L/3L (33%)

38

How are FEV and FVC related?

FEV = 1/ FVC

39

Peek expiratory flow rate occurs around how many liters of air expired?

1 L

40

What % of VC is expired at the peek expiratory flow rate?

25%

41

True or False? Recoil of the lungs increases in inspiration.

T

42

FEF from 15-75% is called:

Mid maximal expiratory flow (MMEF)

43

How will increasing R affect the FEF?

decrease (R = resistance?)

44

Lungs compliance =

delta V/ delta P

45

Compliance must be corrected for:

changes in lungs volume

46

Diseases that cause a reduction in compliance:

emphysema, obstructive pulmonary fibrosis or restrictive diseases

47

What kind of flow occurs in the small airways?

laminar flow

48

Velocity in airways =

P(pi)(r^4)/8nl

49

R =

delta P/V

50

delta P/V =

8nl/(pi)(r^4)

51

Are the small airways in parallel or series?

parallel

52

Factors contributing to airway resistance:

resistance decreases with lung volume, conductance, density of inspired gas, neural control of airway, irritants, and agents

53

Conductance =

1/Resistance

54

How is the density of inspired gas affected by pressure?

increases pressure, increases density

55

True or False? Lung volume resistance increases as lung volume decreases.

F. resistance decreases as lung volume decreases

56

Stimulation of what increases resistance due to airway constriction via smooth muscle?

efferent vagal nerves

57

List agents that can contribute to airway resistance:

histamine, acetylocholine, throboane A(2), prostoglandin F(2), and leukotrienes due to allergens and viral infections

58

Effect of the postganglionic neurotransmitter Norepinephrine on airway resistance:

inhibits constriction, stimulation of sympathetic

59

Maximum inspiratory flow is __ dependent.

effort (1/2 TLC and RV)

60

Does force increase or decrease with lung volume?

decrease

61

Does recoil pressure increase or decrease with lung volume?

increase

62

Does resistance increase or decrease with lung volume?

decrease

63

True or False? Expiratory flow resistance is effort-dependent.

F. effort-independent

64

When does compression of the airways occur?

P outside > P inside

65

Crackles are caused by:

the "popping open" of small airways and alveoli collapsed by fluid, exudate, or lack of aeration during expiration.

66

what are the inherent mechanical properties of the lung?

elastic and flow resistance forces

67

OABCD:

elastic resistance

68

AECF:

non elastic resistance

69

AECB:

non elastic resistance during inspiration

70

ABCF:

non elastic resistance during expiration

71

What % of total body O2 gas flow does the body normally require?

2-5%

72

The expired flow rate can be increased up to:

15-20% of total body O2 gas flow