Physical Aspects of Breathing Flashcards
(65 cards)
1
Q
purpose of conducting airways
A
- warm, humidify, and cleanse inhaled air
2
Q
respiratory defense mechanisms
A
- anatomic
- mechanical
- immune
- general
3
Q
anatomic respiratory defense mechanisms
A
- upper airway (nose)
- epiglottis/larynx
4
Q
mechanical respiratory defense mechanisms
A
- mucociliary and cough clearance
5
Q
immune respiratory defense mechanisms
A
- innate
- adaptive
6
Q
innate immune respiratory defense mechanisms
A
- lysozyme
- lactoferrin
- defensins
- complement
7
Q
adaptive immune respiratory defense mechanisms
A
- secretory IgA
- humoral antibody
- cellular immunity
8
Q
general respiratory defense mechanisms
A
- alveolar macrophages
- inflammatory response
- anti-oxidants
- anti-proteases
9
Q
why does the amount of O2 consumed differ from the CO2 produced?
A
- depends on the source of carbon in the diet
10
Q
what do we use the alveolar gas equation for
A
- compare alveolar gas to blood gas
- determine how well the lungs are working
11
Q
Dalton’s law
A
- total pressure of a mixture of gases is the sum of the pressures exerted by each gas
12
Q
Henry’s law
A
- the amount of gas dissolved in the liquid is directly proportional to the partial pressure of the gas above the liquid
13
Q
what happens with pulmonary capillary blood and alveolar gas in a healthy lung
A
- pulmonary capillary blood equilibrate with alveolar gas
14
Q
PAO2 in the body
what does the A stand for
A
- 104 mmHg
- alveolar
15
Q
PACO2 in the body
A
- 40 mmHg
16
Q
branching pattern of the airways in the lung
A
- dichotomous branching patterns
17
Q
how many generations of branching
A
- 23
18
Q
which are the cartilaginous airways?
A
- bronchi
19
Q
which are the non cartilaginous airways?
A
- bronchioles
- terminal bronchioles
20
Q
what constitutes the conducting zone
A
- bronchi
- bronchiole
- terminal bronchiole
21
Q
important component of respiratory bronchioles
A
- alveoli
22
Q
what constitutes the respiratory zone
A
- respiratory bronchiole
- alveolar duct
- alveolar sac
23
Q
capillaries in the conducting zone
A
- not close enough to inspired air for gas exchange to occur
24
Q
capillaries in the respiratory zone
A
- close enough to inspired air for gas exchange to occur
25
what is anatomic dead space
- air in the conducting zone that cannot contribute to gas exchange
26
where do we find most vascularization in the lung?
- within the alveoli
27
importance of branching of airways in regard to cross sectional area
- aggregate cross-sectional area of the airways increases with each generation
28
expansion of the lung during inspiration is achieved by ______ in thoracic volume
- an increase in thoracic volume
29
muscles involved in quiet breathing during inspiration
- contraction and downward movement of diaphragm
| - contraction of external intercostals
30
muscles involved in quiet breathing during expiration
- no active muscular contraction
| - driven by elastic recoil of viscera, rib cage, and lung
31
muscle involved in forced expiration
- contraction of abdominal muscles and internal intercostals
| - nonmuscular: lung elastic recoil
32
how do we express alveolar pressure
- cmH2O
33
alveolar pressure at end expiration
0 cm H2O
34
alveolar pressure during inspiration
importance of this
- 1 cm H2O
| - pressure becomes more subatmospheric and creates a driving force for the inward flow of air
35
where is the intrapleural space location
- between the outer surface of the lung and the inner surface of the thoracic cavity
36
intrapleural pressure at end expiration
-5 cm H2O
37
intra pleural pressure during inspiration
-8 cm H2O
38
what pleura lines the lung
- visceral pleura
39
what pleura lines the chest cavity
- parietal pleura
40
pleural fluid originates as
- ultra filtrate from the chest wall systemic microcirculation
41
pleural fluid exits via
- via parietal pleural lymphatic stomata
42
why is there negative pressure in the pleural space?
- balance between lung wanting to collapse and chest wall wanting to spring out develops a suction (negative pressure) between them
43
sub atmospheric pressure in the pleural space at end-expiration is caused by
- tendency of the lung to collapse and ribs to spring outward
44
why does intrapleural pressure become more negative during inspiration?
- due to Boyle's Law
- thoracic cavity volume is increased
- pressure drops when volume increases
45
what is transpulmonary pressure
how do we calculate it
usual value
- pressure difference across the surface of the lung, relative to alveolar pressure
- alveolar pressure - intrapleural pressure
- usually positive
46
importance of positive value of transpulmonary pressure
- holds lungs open at end-expiration (because intrapleural pressure is negative)
- when transpulmonary pressure increases during inspiration to overcome elastance of lung, lung inflates
47
compliance of the lung formula
- change in volume / change in pressure
48
elastance definition
- inverse of compliance
49
process of lung inflation during inspiration
- inspiratory muscles contract
- thoracic cavity expands
- intrapleural pressure becomes more negative
- transmural pressure gradient increases, creates subatmospheric alveolar pressure
- air flows inward and lung inflates
50
mechanical energy transferred where during end expiration
- from chest wall to lungs to keep lungs expanded
51
mechanical energy transferred where during end inspiration
- from lung to chest wall due to elastic recoil of lungs
52
why does expiration during a quiet tidal breath take longer than inspiration
- typically passive and not driven by active muscular contraction
- driven by elastic recoil of the lung
53
volume of a single inspiration or expiration
- tidal volume
54
maximal volume that can be inhaled following a normal inspiration
- inspiratory reserve volume
55
volume which can be forcibly expired from a normal expiration
- expiratory reserve volume
56
volume remaining after a maximal expiration
- residual volume
57
volume remaining in the lungs after a tidal expiration
- volume when the system is relaxed
how to calculate
- functional residual capacity
| - ERV + RV
58
maximum volume of gas that can be inspired following a tidal expiration
- the most air you can inspire
how to calculate
- inspiratory capacity
| - TV + IRV
59
maximal volume of gas which can be expired following a maximal inspiration
- the most air you can exhale
how to calculate
- vital capacity
| - TV + IRV + ERV
60
sum of all four non overlapping lung volumes
how to calculate
- total lung capacity
| - RV + ERV + TV + IRV
61
what do we use a body plethysmograph for
- measurement of the residual volume and functional residual capacity
62
what does functional residual capacity define
- mechanical equilibrium between the lung wanting to recoil inwards and ribs wanting to spring out at the end of a tidal breath when no active force is applied to the system
63
pressures in lung compared to pressures in vascular system
- low
| - easier to move air than liquid
64
what will alveolar pressure be during expiration
- more positive
65
what will intrapleural pressure be during expiration
- less negative
