Quiz 4 Physical Princiles of Gas Exchange Flashcards Preview

GNURS627/Respiration/Physiology for Anesthesa > Quiz 4 Physical Princiles of Gas Exchange > Flashcards

Flashcards in Quiz 4 Physical Princiles of Gas Exchange Deck (50):
1

What is the mechanism and rate of molecule transfer dependent on ?

-Physics of gas diffusion
-Partial pressures of gases involved.

2

What is the energy source for gas diffusion?

Kinetic motion

3

Molecular movement is continual and random?

True

4

Movement of a gas in one direction is the effect of what?

Concentration gradient

5

Direction of diffusion occurs for areas of ______ to _______ concentration.

High, low

6

Rate of diffusion is dependent on what?

Pressure

7

What is partial pressure?

The pressure a gas would exert by it's self.

8

What is the total pressure of a mixture?

The summation of all the partial pressures in a gas.

9

Each gas exerts its own individual pressure on the respiratory wall surface?

True.

10

What is the mixture of air?

Nitrogen 79%
Oxygen 21%

11

What is the total pressure of the air mixture?

760 mm Hg

12

What does 1 atmosphere equal?

760 mm Hg

13

What is the partial pressure of nitrogen in one atmosphere?

600 mm Hg

14

What is the partial pressure of oxygen in one atmosphere?

160 mm Hg

15

What does Henry's Law say about the solubility of a gas in a liquid?

Depends on the
-temperature
-partial pressure of the gas over the liquid
-nature of the solvent
-nature of the gas

16

What is high soluble mean?

When dissolved molecules are attracted by water more can be accumulated without building up excess pressure in a solution.

17

What does poorly soluble mean?

Molecules which are repelled by water will dissolve less and have lower concentration

18

What is the rate of net diffusion determined by?

Difference of partial pressure (pp).

19

If the pp of gas in the alveoli greater than blood which way will the gas move?

The gas will move into the blood.

20

What is the vapor pressure when a gas mixture is fully humidified at 37 C?

47 mmHg.

21

What is vapor pressure of water?

Partial pressure of water escaping surface into gas phase.

22

What factors affect gas diffusion rates in fluid?

-pressure differences
-gas solubility in fluid
-area of fluid
-Distance which gas must diffuse
-molecular weight of gas
-Temperature of fluid

23

What is diffusion coefficient of the gas?

characteristics of the gas which affect the ability and rate of net diffusion.
(Solubility/ *square root* Molecular weight)

24

What is the limiting factor for gas movement into tissues?

diffusion rate of gas through tissue water.

25

Alveolar air does NOT have the same gas concentration as atmospheric air?

True

26

How many normal alveolar ventilation removes half of the gas?

17 seconds

27

What is the normal alveolar PO2?

100 mm Hg

28

What is the normal alveolar PCO2?

40 mm Hg

29

Alveolar air is ______ at end of exhalation.

expired

30

How thick is the alveolar membrane?

0.6 micrometers

31

What is the total surface area of the alveolar?

70 square meters

32

How wide is the alveolar capillaries?

0.5 micrometers

33

What are the factors that affect rate of gas diffusion through the respiratory membrane?

1. Thickness of the membrane
2. Surface area of the membrane
3. Diffusion coefficient
4. pressure difference across the membrane

34

CO2 diffuses ___ times faster than Oxygen.

20

35

Oxygen diffuses _______ as rapidly as nitrogen.

twice

36

Can the factors which affect diffusion through the respiratory membrane affect the diffusion capacity?

Yes

37

What is the diffusing capacity?

Volume of a gas that will diffuse through the respiratory membrane each minute for a pressure difference of 1 mm Hg.

38

What is the diffusing capacity for O2?

21 ml/min/mmHg

39

How do you get the total quanitity of O2 diffusing across the membrane per minute?

Pressure difference multiplied by the diffusing capacity.

40

How much does exercising increases the diffusing capacity to?

65 mm/min/mmHg

41

What increases the diffusion capacity during exercising?

-recruiment of capillary fields
-better ventilation/perfusion match with blood (All ZONE 3)

42

CO2 diffusing capacity estimates based on ______ _______.

diffusion coefficient

43

Diffusing capacity of CO2 at resting is ________ and during exercise is ______?

400 mL/min/mmHg,

1200 mL/min/mmHg

44

If the V/Q ratio is either zero or infinity there is ______ exchange of gases.

NO

45

When V/Q = Zero this means what?

There is no ventilation

46

When V/Q = infinity this means what?

There is no perfusion

47

Normal deoxygenated blood PO2 is _____..

40 mmHg

48

Normal deoxygenated blood PCO2 is _____.

45 mmHg

49

Inspired air PO2 is ______ mmHg

150

50

Inspired air PCO2 is ______mmHg.

0