Brainscape's Knowledge GenomeTM

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


See full index

Physiology > Gas Exchange > Flashcards

Gas Exchange Flashcards

1
Q

What does effective respiration mean?

A

enough oxygen intake to meet metabolic demands

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

In respiratory physio, solution refers to what?

A

Water vapor, body fluid, interstitial fluid, and cytosol

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

What is Dalton’s law of partial gas pressure?

A

Each gas exerts a portion of the total pressure in an environment. Thus:

Ptotal = (P1+P2+Pn)

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

What happens to the air we inhale? What is the consequence of this for Dalton’s law?

A

Water vapor added, so this much be subtracted to find partial pressure

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

What is the equation for a particular species of gas, once in the lungs and saturated with water vapor?

A

Px= Fx(Pb-Ph20)

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

What is Henry’s law? Equation?

A

The partial pressure exerted by a gas when dissolved

Partial pressure = [C] of dissolved gas / solubility coefficient

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

Does conjugated oxygen or CO2 exert any pressure?

A

No, it is the dissolved form of gas that exerts a partial pressure

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

Is CO2 more or less soluble than oxygen? What is the effect of this?

A

Much more, thus it exerts much less partial pressure than oxygen, and it much more easily uptaken in the tissues

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

What is the ideal gas law? What are the variables in human tissues?

A

PV=nRT

PV and n

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

Is respiratory physio, gas will continue to flow down its gradient until what point?

A

P1V1 = P2V2

i.e. until partial pressures in alveoli and blood are equal

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

What is Fick’s law of diffusion?

A

The amount of gas that moves across across a tissue sheet is proportional to the area, but inversely proportional to the thickness

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

What is the equation of Fick’s law?

A

diffusion = dP(A)(S) / D(MW^.5)

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

What are the two variable that need consideration with gas exchange through capillaries?

A

Diffusion

Perfusion

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

What does A mean in respiratory physio? a?

A 
A = alveolar
a= arterial
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the location of gas exchange?

A

The respiratory unit

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

What are the components of the respiratory unit?

A

Bronchiole
Alveolar ducts
Atria
Alveoli

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

How does atelectasis change the Fick’s equation?

A

∆P and A are decreased

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

How does pneumonia change the Fick’s equation?

A

Interstitial tissues and alveoli are inflamed, with increased fluid thickness, so the
distance through which gases must diffuse increases, and diffusion rate decreases

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

How does pulmonary edema change the Fick’s equation?

A

Increases D (thickness)

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

How does pulmonary fibrosis change the Fick’s equation?

A

Increases D (thickness)

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

Where does the blood comes from in hemoptysis?

A

From the respiratory membrane

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

What happens to the slope of the blood pO2 pressure curve during exercise? Why?

A

Lowers the slope

Higher perfusion (HR up), meaning less time for diffusion to happen

23
Q

What are the two factors that determine the tissue PO2?

A

Rate of blood flow

Rate of tissue metabolism

24
Q

Why is there a drop in the PO2 when it arrives at the left side of the heart?

A

Shunt of the pulmonary circulation from the bronchial arteries

25
Q

Why is only a small pressure difference needed to exchange CO2? (~5 mmHg)

A

High solubility coefficient

26
Q

What are the two variables that determine [PCO2] in tissues?

A
  1. Rate of tissue metabolism

2. Rate of blood flow

27
Q

What happens to the slope of the PCO2 in alveolar capillaries during exercise? Why?

A

Lowers slope (absolute value)

Increased HR

28
Q

What is used to measure the lungs ability to transfer gases? Why?

A

CO because it is taken up, stays in, and is not used by tissues

29
Q

What is the equation for the diffusion capacity of the lung?

A

DLCO = Jco / PAco

30
Q

A decrease in DlCO means what?

A

Lower rate of diffusion of oxygen

e.g. in thickened or damage respiratory membrane or anemia

31
Q

What does COPD do to DlCO?

A

Decreases it

32
Q

What does pulmonary fibrosis do to DLCO?

A

Decreases it

33
Q

What does interstitial lung disease do to DLCO?

A

Decreases it

34
Q

What does pulmonary HTN do to DLCO? Why?

A

Decreases it

Increase in capillary wall thickness

35
Q

What does chronic pulmonary thromboembolism do to DLCO?

A

Decreases it

36
Q

What does anemia do to DLCO?

A

Decreases it

37
Q

What does polycythemia do to DLCO?

A

Increases it

38
Q

IS DLCO sensitive? Specific?

A

Sensitive, but NOT specific

39
Q

What happens to the partial pressure of CO2 as you move from tissues to lungs?

A

Decreases

40
Q

What is the atmospheric pressure at sea level in mmHg?

A

760 mmHg

41
Q

What is the solubility coefficient of oxygen? CO2? What does this mean?

A 
Oxygen = 0.024
CO2= 0.57

Thus CO2 is much more soluble in water

42
Q

What are the two variables we can change in the partial pressure equation Px = Fx(Pb-Ph2o)? How?

A

Fx (with oxygen)

Pb (with hyperbaric chamber)

43
Q

According to Fick’s law, the larger the surface area of a tissue, the (higher/lower) the rate of diffusion

A

Higher

44
Q

According to Fick’s law, the thicker a tissue is, the (higher/lower) the rate of diffusion

A

Lower

45
Q

What is the partial pressure of oxygen in the pulmonary capillaries at the arterial end? Venous end?

A

Arterial end = 40 mmHg

Venous end = 104 mmHg

46
Q

True or false: under normal. resting conditions, the entire capillary/alveolar surface area is needed to diffuse oxygen.

What is the consequence of this?

A

False–it’s more like a third.

This allows a buffer for times during increased oxygen demand (such as exercise)

47
Q

(Summarizing the O2 diffusion graph): If there is an increase in tissue metabolism, how is the higher demand for oxygen met? How does increase oxygen demand change the curve?

A

Increasing blood flow

The curve shifts downward (more blood flow is needed to attain each PO2 mmHg)

48
Q

What does the graph of the blood flow to mmHg PO2 look like?

A

Square root

49
Q

What does the graph of the blood flow to PCO2 mmHg look like?

A

1/x

50
Q

What happens to the curve of CO2 diffusion with increased metabolism?

A

Shifts rightward (meaning that a higher blood flow is needed to achieve the same mmHg pCO2)

51
Q

In determining the diffusing capacity of the lungs, why is it that the partial pressure of CO can be used directly in the equation, rather than the amount that is dissolved in blood like the other gases?

A

Hb picks it up so readily, that the partial pressure = the dissolved pressure

52
Q

How do you convert the DLCO (diffusion rate of CO) to the diffusion rate of O2?

A

Multiply by the diffusion factor coefficient for oxygen (1.23)

53
Q

Why is there a lower diffusion rate of O2 in pulmonary HTN?

A

Increases in capillary wall d/t higher pressures

54
Q

What does the alveolar gas equation tell you?

A

What fraction of oxygen the patient is taking in

Physiology (75 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions