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Flashcards in Airway closure Deck (30)
1

What is the physiological basis of airway closure?

Pressure drops as fluid flows through a tube

P1 > P2

AKA- As gas flows through a tube, pressure falls. In the airway, pressure decreases as gas flows along the bronchioles.

2

Forces keeping airway open during inspiration and forces causing closure during forced expiration:

During forced expiration intrapleural pressure becomes what? 

 

Positive

30 cm H20 in picture

 

3

Forces keeping airway open during inspiration and forces causing closure during forced expiration:

the high intrapleural pressure (30 cm H2O) is transmitted to the what?

Alveoli 

38 cm H2O in this picture

4

Forces keeping airway open during inspiration and forces causing closure during forced expiration:

As the air flows along the airway, the pressure in the airway begins to what?

fall

(remamber as fluid or gas flows through a tube, pressure falls)

5

Forces keeping airway open during inspiration and forces causing closure during forced expiration:

At some point in the airway the intrapleural pressure sufficiently exceeds airway pressure, and the airway does what?

closes

6

Forces keeping airway open during inspiration and forces causing closure during forced expiration:

in the diagram the airway closes when the pressure falls to 19cmH2O

 

7

why does the trachea not close then?

b/c it has rings

8

what part of the airway is suceptable ro collapsing

bronchioles to alveoli 

9

why do the mainstems not collapse?

b/c they have rings also

10

Closing volume (CV) and Closing Capacity (CC):

at some point during forced expiration, airways begin to close. The volume that can subsequently be exhaled is called the 

 

closing volume

11

Closing volume (CV) and Closing Capacity (CC):

What makes up the closing capacity

the closing capacity is the closing volume plus the residual volume

CC = CV + RV

12

Closing volume (CV) and Closing Capacity (CC):

the CV and CC are measures how?

nitrogen washout test 

and

helium dilution method

13

Closing volume (CV) and Closing Capacity (CC):

what happens if your CC is higher than your FRC?

you have no reserve (no FRC)

14

Closing volume (CV) and Closing Capacity (CC):

what typw of pt may have a CC higher than FRC

Elderly

15

Closing volume (CV) and Closing Capacity (CC):

since older peoples CC exceeds their FRC what does this mean in relation to thir airway closure?

they close without forced expiration

16

Young VS Eldery CC

 

17

Fast Facts about Airway closure:

Airway closure in the yooung healthy individual during expiration at low lung volumes; expiration must be forced to acheive lung volumes where airway closure occurs

just read

18

Fast Facts about Airway closure:

In young healthy individuals airway closure (CV) occurs at a lung volume equal to about __% of VC

10%

19

Fast Facts about Airway closure:

the volume at which airway closure occurs _____ with age 

increases

20

Fast Facts about Airway closure:

CV are increased with what type of Airway dz

Obstructive

(asthma/COPD/ bronchitis)

21

Fast Facts about Airway closure:

what are other things that can increase closing volumes

Smoking

bronchospasm

Airway secretions

Fluid retention

Anesthesia/surgery

22

does pulmonary compliance increase or decrease with age?

increases

23

How does FRC change w/ age?

since the lung does not recoil inward with as much force, FRC INCREASES slightly with age ~10%

24

does chest wall compliance increase or decrease with age?

decreases

25

FRC = what

FRC = RV + ERV

26

VC = what

VC = ERV + TV + IRV

27

what happens to FRC w/ obstructive dz?

increased

28

what happens to VC with obstructive Dz

decreased

29

what happens to TLC with obstructive dz

increase

30

what happens to FRC, VC, and TLC with restricted dz

all decreased

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