Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

respiratory physio > physical principles of gas exchange > Flashcards

physical principles of gas exchange Flashcards

1
Q

air is composed of

A

79% nitrogen, 21% oxygen

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

total pressure of air mixture -

A

760 mmHg

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

1 atm

A

760

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

nitrogen partial pressure is

A

79% of 760= 600

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

oxygen partial pressure is

A

21% of 760 = 160

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

henrys law

A

the solubility of a gas in a liquid depends on temp, the nature of the solvent, and the nature of the gas.

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

the colder, the ___ gas is dissolved

A

more

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

gas is ____ soluble at high temps

A

less

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

gas is ___ soluble at low temps

A

more

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

net diffusion of gases is determined by

A

differences in partial pressures

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

if pp of gas in alveoli > blood,

A

gas moves into blood

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

if pp of gas in blood > alveoli,

A

gas moves into alveoli

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

vapor pressure is ___ mmHg when gas mixture is fully humidified at 37degrees

A

47

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

factors that affect gas diffusion rates

A

pressure, gas solubility, distance, molecular weight, temp

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

diffusion coefficient is dependent on

A

solubility and molecular weight

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

if a gas is highly soluble, it has a ___ diffusion coefficient

A

high. direct relationship

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

if a gas is less soluble, it has a ___ diffusion coefficient

A

low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

heavier gases move

A

more slowly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

D is ____ to the square root of the gas’ molecular weight

A

inversely proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

rate of gas movement into tissues is limited by diffusion rate of gas through

A

tissue water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

alveolar air is ___ replaced by atmospheric air during each breath

A

partially. protects you and acts as a buffer from sudden changes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

each breath replaces ___ of FRC

A

1/7th

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

normal alveolar ventilation removes 1/2 of gas in ___ seconds

A

17

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

half normal ventilation removes 1/2 of gas in __ seconds

A

34

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
twice normal removes half of gas in
8 seconds
26
normal alveolar PO2 is ___ mmHg
100
27
how much o2 do you need to consume at rest a minute
250ml
28
normal alveolar PCO2 Is ___ mmHg
40
29
alveolar PCO2 ___ in proportion to CO2 excretion
increases
30
PCO2 ___ in inverse to alveolar ventilation
decreases
31
alveolar air is expired at
end of exhalation
32
overall thickness @ ___ mm
.6
33
total surface area
70 sq meteres
34
RBC squeeze through __ mm diameter capillaries
5
35
ficks law tells you about
diffusion of gas thru a tissue membrane
36
if the resp membrane is thicker, the rate of diffusion will be ____
slower
37
increasing thickness by ___ times interferes significantly with normal resp exchange
2-3
38
decreasing surface area ____ gas exchange
decreases
39
decreasing by ___ normal impedes gas exchange significantly
1/4
40
emphysema
dissolution of many alveolar walls to collapse alveoli into larger chambers. (surface area decreased as much as 5-fold)
41
oxygen diffusion compared to nitrogen
o2 is twice as fast
42
CO2 diffusion compared to oxygen
co2 is 20 times faster
43
CO2 diffusion compared to oxygen
co2 is 20 times faster
44
diffusing capacity definition
the volume of a gas that will diffuse through the resp membrane each minute for a pressure diff of 1 mmHg
45
the pressure difference multiplied by the diffusing capacity =
the total quantity of O2 | diffusing across the membrane per minute
46
with exercise diffusing capacity increases three fold to max at
65
47
during exercise the lung is in zone
3
48
diffusing capacity of CO2 at rest
400
49
diffusing capacity of CO2 during exercise
1200
50
the more soluble in water,
the faster diffusion
51
which gas is the least soluble
nitrogen
52
pressure difference affects gas diffusion how
difference in partial pressures of gas in alveoli and pulmonary blood
53
CO2 is highly
soluble. diffuses rapidly thru resp membrane
54
if v/q ratio is either zero or infinity
there is no exchange of gases
55
if ventilation is present but no perfusion then v/q =
infinity
56
if ventilation = zero but perfusion is present, the v/q is
zero (complete airway obstruction) like mucus plug
57
if v/q is zero, alveolar concentration will equal
venous blood. air in alveoli reaches equilibrium with deoxygenated blood returning to lungs in pulm arteries
58
in normal deoxygenated blood the PO2 is
40
59
in normal deoxygenated blood the PCO2 is
45
60
when v/q equals infinity, the alveolar air..
becomes equal with humidified inspired air. no loss of oxygen into blood. no gain of co2 from blood
61
when v/q equals infinity, P02 is
150
62
when v/q equals infinity, pco@
0
63
normal alveolar po2
100
64
normal alveolar pco2
40
65
pulm embolus
infinity
66
if v/q is below normal
perfusion but no ventilation. blood is being shunted from PA to pulm vein without participating in gas exchange
67
the greater the shunt, the greater the amount of blood that
fails to be oxygenated in lungs
68
dead space
vent but no perfusion. ventilation to alveoli is good but blood flow is low
69
physiologic dead space includes
wasted ventilation, anatomical dead space
70
v/q ration greater than normal
dead space. PE and what else?
71
the more rapidly o2 is absorbed, the ____ its concentration in the alveoli becomes,
lower
72
the more rapidly new o2 is breathed into the alveoli from the atmosphere, the ___ the concentration becomes
higher
73
the greater the physiologic shunt, the greater the
amount of blood that fails to be oxygenated as it passes thru the lungs
74
ficks law
(a x pp x d) / thickness
75
diffusion coefficient depends on
solubility + .. and weight -
76
normal CO2 production at rest
200ml/min
77
PO2 100 when leaving pulm but LA blood is ___ because of?
95 because of bronchial circulation blood.
78
why is pp of o2 in upper airway 150
water vapor.. 713 + 47
79
frc is roughly
2500ml
80
___ ml air per breah
330
81
during exercise, dead space is ___
reduced

respiratory physio (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions