Gas Exchange and O2 Transport Flashcards

1
Q

Surfactant is a lipid protein complex that is produced by…

A

Type II alveolar cells.
surfactant contains hydrophobic and hydrophilic regions that allow it to incorporate into air-liquid interface

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

Surfactant reduces ___ to a greater extent in smaller v. larger alveoli and prevents ___

A

surface tension; atelectasis = alveolar collapse

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

Surfactant reduces ___ which increases lung compliance and reduces ___

A

surface tension; inspiratory work

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

Surfactant reduces ___ which also reduces ___ in the alveoli

A

surface tension; fluid accumulation

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

Elastic Properties of the Lung

A

Inward elastic recoil facilitates exhalation

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

Elastic Properties of the Chest Wall

A

Outward elastic recoil facilitates inspiration

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

At volumes above functional residual capacity, the net recoil pressure of the respiratory system factors…

A

a decrease in lung volume
maintained by the actions of the muscles of inspiration

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

At lung volumes below functional residual capacity, the net recoil pressure of the respiratory system favors…

A

an increase in lung volume
maintained by the actions of the muscles of expiration

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

If intrapleural pressure is raised to atmospheric pressure (during puncture pneumothorax) the unopposed lung tissue will recoil ___ while the opposed chest wall will spring ___

A

inward; outward
This results in a collapsed lung

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

During a pneumothorax, the intrapleural pressure becomes the same as atmospheric pressure. as a result…

A

the lung collapses inward and the chest wall springs outward

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

Gas exchange at the capillaries occurs by

A

passive diffusion

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

Typical dry air contains ___ nitrogen and ___ oxygen and negligible amounts of CO2 and other gases. Combined, they exert the barometric pressure, which at sea level is 760mmHg.

A

79%; 21%

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

the partial pressure exerted by a gas is

A

directly proportional to the percentage of that gas in the total air mixture

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

Dalton’s Law

A

Px = Pb * Fx

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

Like any gas, water vapor exerts a partial pressure. At body temperature, the partial pressure of H2O vapor is

A

47mmHg
humidification of inspired air effectively dilutes the partial pressure of other inspired gases by 47mmHg

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

PIO2 =

A

(Pb - Ph20) * FO2
Ph2o = 47mmHg
FO2 = 21%

17
Q

end tidal PO2 and PCO2 are good measures of

A

alveolar PAO2 and PACO2
towards the end of expiration, the air expired is alveolar air

18
Q

PAO2 = PIO2 - PACO2 only works if…

A

O2 consumption = CO2 production

19
Q

For a mixed diet, RQ is ___.
CO2 production =___ of O2 consumption

20
Q

Alveolar Gas Equation

A

PAO2 = PIO2 - (PACO2/RQ)

21
Q

an ___ relationship exists between PACO2 and alveolar ventilation

22
Q

if ventilation doubles, the PACO2 will be ___ by ___

A

reduced by half

23
Q

Gas Transfer across pulmonary capillaries

A

O2 partial pressure gradient from alveoli to blood = 60mmHg (100–>40)
CO2 partial pressure gradient from blood to alveoli = 6mmHg (46–>40)

24
Q

Gas Transfer across Systemic Capillaries

A

O2 partial pressure gradient from blood to tissue cell = 60mmHg (100–>40)
CO2 partial pressure gradient from tissue cell to blood = 6mmHg (46–>40)

25
Rate of Gas Exchange Across Alveolar Membrane is dependent upon 4 things:
1. Partial pressure gradients 2. Surface area for diffusion: increase with exercise and decreases with emphysema and atelectasis 3. solubility of gases 4. thickness of alveolar membrane
26
Pneumonia
inflammatory fluid accumulation within alveoli
27
Pulmonary fibrosis
chronic airway irritation replaces lung tissues with fibrous tissue
28
Pulmonary Edema
increase in vascular permeability or pulmonary pressure (congestive heart failure), increases interstitial fluid