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EXCI 357 Pulmonary Physiology > 1.Pulmonary_ventilation_mechanics_compliance_work of breathing > Flashcards

1.Pulmonary_ventilation_mechanics_compliance_work of breathing Flashcards

1
Q

4 major functions of respiration

A
  1. Pulmonary ventilation
  2. Diffusion of O2 and CO2 between alveoli and blood
  3. Transport of O2 and CO2 in blood and body fluids to and from tissue cells

4 .Regulation of ventilation and other facets

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2
Q

What is pulmonary Ventilation?

A

inflow and outflow of air between atmosphere and lung alveoli

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3
Q

Inspiration and expiration are two entirely ________ processes that rest on variations of _______in thoracic cavity

A

mechanical

pressure

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4
Q

Volume variations result in pressure variation which ultimately leads to?

A

movement of air –> pressure equalization

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5
Q

Air always goes from an area of _____ pressure to an area of _____ pressure

A

high

low

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6
Q

Volume of chest cavity can be modified in two ways. What are they?

A

Vertically

Antero-posteriorly

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7
Q

Elevation or depression of the ribs to increase or decrease the ______of the chest cavity is accomplished by what muscles and is known as?

A

diameter
intercostal muscles
Antero-posterioral modification of the chest volume

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8
Q

Vertical modification of the chest cavity volume by ______or _______movement of the ________ to lengthen or shorten the chest cavity

A

downward
upward
thorax “floor“

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9
Q

Major muscles responsible for volume changes during inspiration?

A

Diaphragm

–> Actively contracts and flattens

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10
Q

Increase in intra-thoracic volume in the antero-posterior direction is due to which muscles?

A 
External intercostals (mainly)
Parasternal intercostals
Anterior serrati
Scaleni (in deep breath)
Sternocleidomastoid (in deep breath)
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11
Q

Is elastic recoil powerful enough to cause rapid expiration during exercise?

A

No.
During Exercise Elastic recoil plus contraction of abdominal muscles (vertical expansion) and internal intercostals (antero-posterior) results in forced expiration. As elastic recoil is not enough to meet the needs of exercise.

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12
Q

Elastic recoil plus contraction of ________ (vertical ) and ________ (antero-posterior)

A

abdominal muscles

internal intercostals

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13
Q

Internal intercostal, further ________of the ribs______and _____ thereby ______ total lung volume

A

depression
down
In
Decreasing

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14
Q

At rest, Inspiration begins with contraction of ______ and ________

A

diaphragm and

external intercostals

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15
Q

A .Which actions “lower floor” of thorax and lift ribs up and out.
B. This marks the beginning of inspiration or expiration?

A

A. contraction of diaphragm and external intercostals

B. inspirations

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16
Q

The “lowering floor” of thorax and lifting of the ribs up and out cause the Volume of _______ to (increase/decrease)_____ and intrapulmonary pressure to (increase/decreases)_______ below _________ pressure.

A
  • thorax
  • increase
  • Decrease
  • atmospheric pressure
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17
Q

What causes Atmospheric air moves into pulmonary system, and why does this result in the movement of air into the pulmanry system?

A
  1. Volume of thorax increases and intrapulmonary pressure decreases below atmospheric pressure –. Thereby creating a pressure gradient between atmospheric air and pulmonary air.
  2. To equilibrate pressure gradient between lung and atmosphere
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18
Q

True or false. During exercise breathing frequency goes up markedly inorder to meet the metobolic needs of the system?

A

False.
TL;DR : Expiration becomes ACTIVE increase in pulmonary ventilation without a dramatic increase in breathing:

Contractions of the internal intercostals pull the ribs down and in, and contractions of the abdominal muscles increase abdominal pressure, forcing diaphragm up into thorax. Which greatly increase maximal amount of ventilatory airflow, so pulmonary ventilation can increase greatly without a dramatic increase in breathing frequency

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19
Q

Describe the elastic nature of the lungs

A

Collapses like a balloon and pushes all its air out through trachea if no force to keep it open => RECOIL

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20
Q

true or false? The lung has no attachments between lung and chest walls except at its hilum.

A

True. Lung floats in thoracic cavity, surrounded by thin layer of pleural fluid

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21
Q

What maintains slight suction between visceral and parietal layers of pleura?

A

Continual suction of excess fluid into lymphatic channels

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22
Q

Pleural pressure (PPL) Is?

A

pressure of fluid in pleural space

23
Q

True or False. Pleural pressure is slightly Positive?

A

False. If it were postive the lungs would collapse on itself and breathing would require A LOT more energy. it is actually negative as result of continual lymphatic draining/ suction; keeping the lungs open

24
Q

What is Normal PPL at beginning of inspiration?

25
True or false? During normal inspiration, expansion of chest cage creates more positive pressure PPL
False. PPL needs to drop well bellow Pair in order for air to flow inwards. Thus it has to become more negative
26
What is (PALV)?
Alveolar pressure: pressure of air inside lung alveoli
27
True or False? When glottis is open and no air is flowing in or out of lungs, pressures in all parts of respiratory tree (including alveoli) equals atmospheric pressure ?
True. This is known as the zero reference.
28
Normal PALV at beginning of inspiration is equal to?
0 cm H2O ( b/c it's = to atmopheric air at this point; zero reference)
29
During normal inspiration PALV Increase or decreses? Why?
Decreases to  -1 cm H2O needs to fall bellow the zero refence ( atmospheric air pressure) in order for in flow of air to occur.
30
During expiration, PALV increases or decreases?Why?
increases to +1 cm H2O Needs to be above zero reffeence ( Atmospheric air pressure) in order for air to flow outwards
31
What is PTran?
Transpulmonary pressure it is the difference between PALV and PPL
32
What does Ptran measure?
Measure of elastic forces in lungs
33
What pressure measures the recoil pressure of the lungs?
Transpulmonary pressure
34
Lung compliance is the measure of? | How is it calculated?
The extent to which lungs expand for each unit of increase in transpulmonary pressure C= delta V/ delta Ptran
35
Average compliance for normal adult ?
200 ml/cm H2O of PTRAN
36
The characteristics of the compliance diagram are determined by what?
The elastic forces of lung
37
Elastic forces of lungs are divided into 2 parts. What are they?
1. Elastic forces of lung tissue itself | 2. Elastic forces caused by surface tension of fluid that lines inside walls of alveoli
38
True or false? Elastic forces of lung tissue | is Determined mainly by elastin and collagen fibers interwoven among lung parenchyma.
True. When lungs are expanded these fibers are stretched | Force that acts to resist distention
39
When lungs are expanded these fibers are ______ | Force that acts to resist distention. This accounts for which one the factors affecting compliance?
Elastin and collagen fibers Stretched Elastic forces of lung tissue
40
The Force that acts to resist distention of the lungs?
Elastic forces of lung tissue | Surface tension of the alveoli
41
This is caused by the attraction between alveolar lining fluid and the air in the alveoli. it results in a force that_______?
Surface tension of the alveoli Acts to resist distention
42
When water forms a surface with air, water molecules on surface of water have a _______attraction to one another, such that water surface is always attempting to?
strong contract (e.g., raindrops held together by tight contractile membrane of water molecules)
43
True or false? On the inner surfaces of alveoli: water surface is attempting to contract; results in attempt to force air out of alveoli through bronchi; causes alveoli to try to collapse; ends up causing elastic contractile force of entire lungs
true
44
What is the Surface active agent in water
Surfactant
45
Surfactant, affects surface are tension how?
Greatly reduces surface tension of water in alveoli
46
true or false surfactant is Secreted by special surfactant-secreting epithelial cells called Type I alveolar cells
False. Secreted by special surfactant-secreting epithelial cells called Type II alveolar cells
47
This surface has from 1/12 to ½ the surface tension of pure water
Surfactant
48
The surface tension produces a force that is directed inward towards the centre of an alveolus and creates a pressure within the alveolus. The pressure (P) can be determined by _______ Law as follows
Laplace Law P= (2xT)/R where T = surface are tension R= Radius of alveolus
49
Ture or false. If Alveoli were lined with pure water instead of surfactant the SA tension would be lower.
False . Surfactant reduced SA tension. Sa tension would be about 4.5 times higher if lined with pure water
50
True or false. The smaller the alveolus, the smaller the alveolar pressure caused by surface tension
False. The smaller the alveolus, the greater the alveolar pressure caused by surface tension
51
Babies having little or no surfactant in alveoli would result in? This is called...
Lungs have an extreme tendency to collapse, sometimes 6-8 times more than in normal adults Respiratory distress syndrome of the newborn
52
True or false. Thoracic cage does not have it's as own elastic characteristics.
False
53
Pressure needed to inflate total pulm. system isalmost ____pressure needed to inflate lungs alone. This measn that compliance of entire pulm. system isabout ___ that of lungs alone?
2x | ½
54
Compliance of total pulmonary system = ?
lungs + thoracic cage

EXCI 357 Pulmonary Physiology (7 decks)

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