Respiratory System: Gas Exchange and Gas Transport in the Blood Flashcards

1
Q

What is the process of randomly moving molecules making their way back and forth across respiratory membrane?

A

diffusion

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

What is termed the molecular impact on surface?

A

pressure

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

What is the term for the pressure exerted by each gas?

A

partial pressure

    • multiple gases in the air
    • rate of diffusion directly related to partial pressure of gas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Partial pressure equation

A

concentration of dissolved gas / solubility coefficient

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

Direction of net diffusion depends on what? (6)

A
  • pressure difference
  • solubility of gas in fluid
  • cross-sectional area of fluid
  • distance gas must diffuse
  • molecular weight of the gas (smaller = better)
  • temperature of fluid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Diffusion equation

A

(change in pressure x area x solubility coefficient) / (distance to diffuse x square root of molecular weight)

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

Do respiratory gases diffuse across a membrane easily?

A

yes

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

What is a limiting factor to rate of diffusion?

A

water

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

Rate of diffusion thru tissue is similar to what?

A

diffusion thru water

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

What respiratory gas is constantly being absorbed from alveoli?

A

O2

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

What respiratory gas is constantly diffusing from blood to alveoli?

A

CO2

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

What is humidified in the respiratory tract?

A

H2O

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

How many mmHg of O2 in alveoli?

A

104 mmHg

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

Amount of O2 in alveoli is controlled by what? (2)

A
  • rate of absorption by pulmonary capillaries

- rate of O2 entry into alveoli via ventilation

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

How many mmHg of CO2 in alveoli?

A

40 mmHg

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

Amount of CO2 in alveoli is controlled by what? (2)

A
  • rate of excretion by pulmonary capillaries

- rate of alveolar ventilation

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

Increase expiration equals what?

A

increase expiration = decrease in CO2 = decrease in PCO2

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

Amount of PO2 in venous blood of capillary?

A

40 mmHg

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

Amount of PCO2 in venous blood of capillary?

A

45 mmHg

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

The amount of O2 in the alveoli can never exceed what?

A

149 mmHg @ sea level if breathing normally

– because that is the max PO2 in the system after it has become humidified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
Diffusion coefficients for the following:
O2
CO2
CO
N2
He
A
O2 = 1.0
CO2 = 20.3
CO = 0.81
N2 = 0.53
He = 0.95
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Alveolar air replacement – how much new air goes into the alveoli with each breath?

A

350 mL

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

What fraction of alveolar air is replaced by new air with each breath?

A

1/7

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

Do we have a quick exchange of O2/CO2?

A

No – it is a more tempered response to partial pressures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What causes diffusion to be rapid?

A

large surface area of respiratory membrane w/ small amount of blood spread throughout

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Pulmonary capillaries have a large or small diameter?

A

small diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What 4 factors is diffusion affected by?

A

a. thickness of membrane
b. surface area of respiratory membrane
c. diffusion coefficient
d. pressure difference across membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The volume of gas that will diffuse thru the membrane from the lungs to the blood each minute for a partial pressure difference of 1 mmHg?

A

Diffusion capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Diffusion capacity of oxygen at rest? During exercise?

A

Rest: ~ 230 ml O2/min
Exercise: max 3x diffusion capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Diffusion capacity of carbon dioxide at rest? During exercise?

A

Rest and exercise: increase proportionately to O2 given that CO2 has a diffusion coefficient > 20x of O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Q =

A

perfusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Va =

A

ventilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Va/Q = normal

A

Va for an alveolus is normal and Q is normal for the same alveolus

34
Q

Va/Q = 0

A
  • Va is zero and there is blood flow

- No gas exchange

35
Q

Va/Q = infinity

A
  • Va is adequate and there is no blood flow

- No gas exchange

36
Q

What do bronchial arteries supply?

A

supply deep tissues of lungs and do not come into contact w/ lung air

37
Q

Blood from the bronchial arteries to the deep tissues of the lungs returns to the left atrium via which veins?

A

pulmonary veins

38
Q

What happens when the blood returns from the lungs to the left atrium? Drops PO2 to levels to what?

A

oxygenated blood mixes with unoxygenated blood and drops PO2 to 95 mmHg

39
Q

How much PO2 in the interstitial fluid surrounding cells?

A

40 mmHg

40
Q

How much PO2 in cells?

A

23 mmHg (O2 diffuses from cells to interstitial fluid)

41
Q

How much PO2 in venous return?

A

40 mmHg

42
Q

How much CO2 flow out of the cell –> interstitial fluid –> capillaries?

A

45 mmHg

43
Q

Is there a less pressure difference to cause CO2 diffusion than O2 diffusion?

A

YES

44
Q

How much PCO2 in cells?

A

46 mmHg

45
Q

How much PCO2 in interstitial fluid?

A

45 mmHg

46
Q

How much PCO2 in the capillaries?

A

45 mmHg

47
Q

How much PCO2 in alveolar air?

A

40 mmHg

48
Q

Decreased blood flow to interstitial fluid _______ PCO2 in fluid

A

increases

49
Q

Increase in blood flow at interstitial fluid _______ PCO2 in fluid

A

decreases

50
Q

Increase in metabolism _______ interstitial fluid PCO2 at all blood flow levels

A

increases

51
Q

How much oxygen does hemoglobin transport from lungs to tissues (hemoglobin saturation)?

A

97% of O2

52
Q

What does the dissociation curve illustrate?

A

% of hemoglobin saturated by O2 @ any given point along transport route

53
Q

When O2 binds with hemoglobin, is PCO2 high or low?

A

high

54
Q

When O2 is released from hemoglobin, is PCO2 high or low?

A

low

55
Q

What causes the dissociation curve to shift to the RIGHT?

A

(more O2 to tissues):

a. increase blood acidity (lower pH)
b. increase CO2
c. increase temperature
d. increase BPG
e. Bohr effect: increase in H+ and CO2 shifts curve to the right
f. exercise

56
Q

What causes the dissociation curve to shift to the LEFT?

A

(less O2 to tissues):

a. Higher pH

57
Q

O2 leaving the lungs has partial pressure of what?

A

95 mmHg

58
Q

O2 leaving the tissues has a partial pressure of what?

A

40 mmHg

59
Q

Hemoglobin saturation percentage of O2 leaving the tissues?

A

75%

60
Q

How many grams of hemoglobin can carry 20 ml O2 in 100 ml blood?

A

15g

61
Q

Normal conditions of O2 release from hemoglobin to tissues?

A
  1. 4 ml O2 to tissues

- - leaves tissues with 14.4 ml O2

62
Q

How much O2 is left in tissues per 100 ml blood?

A

5 ml

63
Q

How much does interstitial fluid PO2 drop during strenuous exercise?

A

40 mmHg –> 15 mmHg

64
Q

How much O2 is delivered to the tissues during strenuous exercise?

A

net delivery of 15 ml to tissues ( 3x the normal amount of O2 delivered)

65
Q

How much does PO2 drop in alveoli?

A

104 mmHg –> 60 mmHg

66
Q

How much does hemoglobin saturation drop in alveoli?

A

97% to 89%

67
Q

PO2 of tissues?

A

35 mmHg

68
Q

PO2 in alveoli can increase to what?

A

500 mmHg

69
Q

hemoglobin saturation cannot increase higher than what percentage?

A

100%

70
Q

Carbon monoxide poisoning?

A
  • CO combines with Hgb @ same location as O2

- CO has higher affinity for Hgb than O2

71
Q

What amount of PCO is lethal?

A

0.6 mmHg

72
Q

What amount of CO2 per 100 ml of blood is transported from tissues to lungs?

A

4 ml

73
Q

Amount of CO2 in plasma?

A

7%

74
Q

CO2 combines with H2o to form what?

A

carbonic acid

75
Q

How much CO2 per 100 ml of blood?

A

50 ml

76
Q

Normal range of CO2 in tissues?

A

45 mmHg

77
Q

Normal range of CO2 in arterial blood?

A

40 mmHg

78
Q

Respiratory Exchange Ratio (RER) compares what?

A

CO2 output to O2 intake

79
Q

Normal uptake of O2?

A

5 ml O2 is taken up by the tissues and 4 ml of CO2 transported from tissues to lungs

80
Q

RERE equation

A
RER = (rate of CO2 output) / (rate of O2 uptake)
Normal values:
a. Carbs: R = 1.0
b. Fats: R = 0.7
c. Carb/Fats/Protein: R = 0.85