M2-C9-L10 --> Gas Exchange

Front 1

OVERVIEW

- Gas travels by diffusion how?

Back 1

- from area of high concentration to low concentration

Front 2

OVERVIEW

- pO2 = ???

- pN2 = ???

- Pressure of Air @ sea level?

Back 2

160 mmHg

600 mmHg

760 mmHg

Front 3

OVERVIEW

- Vapor pressure of water (pH2O) = ???

Back 3

47 mmHg

Front 4

SOLUBILITY COEFFICIENT

- of CO2 ?

- of O2 ?

- of CO (carbon monoxide) ?

- of Nitrogen ?

- of Helium ?

Back 4

0.57

0.024

0.018

0.012

0.008

Front 5

HENRY'S LAW

- Henry's law basically tells us what? x2

Back 5

- how easily does gas diffuse through a membrane
&
- what concentration do we start with

Front 6

HENRY'S LAW

- give the equation

Back 6

Pressure =

= (Concentration of dissolved gas) / Solubility Coefficient

Front 7

CARBON MONOXIDE POISONING

- compare the solubility coefficient of CO to O2.

- what does CO do at the cellular level that causes problems?

- how does this affect pO2 in arterial?

- how does this affect pO2 in venous?

Back 7

- CO has a lower solubility coefficient
(0.018 vs. 0.024)

- binds to hemoglobin much better

- no change

- decreases
(patient becomes cyanotic)

Front 8

NET DIFFUSION RATE

- Diffusion Coefficients for CO2

- for O2

- for CO

- for Nitrogen

- for Helium

Back 8

20.1

1.0

0.81

0.53

0.05

Front 9

NET DIFFUSION RATE

- Factors that affect the rate of gas diffusion in a fluid? x5

Back 9

(MC STD)

- MW of gas
- Cross-Section Area of Fluid

- Solubility of gas in Fluid
- Temperature of Fluid
- Diffusion distance

Front 10

NET DIFFUSION RATE

- what is the Diffusion Rate equation?

Back 10

D = ((SAP) divided by MD)

Front 11

HUMIDIFIED VS. ALVEOLAR AIR

- in humidified air, what has the greatest partial pressure?

- followed by?

- followed by?

- least amount of partial pressure?

Back 11

- N2 @ 563.4 (74%)

- O2 @ 149.3 (20%)

- Water @ 47 (6 %)

- CO2 @ 0.3 (0.04%)

Front 12

HUMIDIFIED VS. ALVEOLAR AIR

- in alveolar air, what has the greatest partial pressure?

- followed by?

- followed by?

- least amount of partial pressure?

Back 12

- N2 @ 569 (75%)

- O2 @ 104 (14%)

- Water @ 47 (6%)

- CO2 @ 40 (5%)

Front 13

HUMIDIFIED VS. ALVEOLAR AIR

- as air travels through the nasal cavity, what happens to the air?

- thus what partial pressure goes up markedly when going from Atmospheric air to Humidified air?

- the above increase in partial pressure comes at the expense of what other partial pressure?

Back 13

- becomes almost 100% humidified

- Partial Pressure of Water
(from 3.7 (0.5%) to 47 (6%))

- Partial Pressure of Nitrogen
(from 597 (78%) to 563 (74%))

Front 14

HUMIDIFIED VS. ALVEOLAR AIR

- when going from Humidified air to Alveolar air, the biggest increase in partial pressure is what?

- what about the biggest decrease in partial pressure?

- what values remain the same for partial pressure? x2

Back 14

- CO2
(from 0.3 (~0%) to 40 (5%))

- O2
(from 149 (20%) to 104 (14%))

- pH2O is the same
- pN2 is the same

Front 15

HUMIDIFIED VS. ALVEOLAR AIR

- the total partial pressure of air for atmospheric air?

- for Humidified air?

- for Alveolar air?

- for Expired air?

Back 15

760 mmHg for all of them

Front 16

N2K REVIEW

- what is the pCO2 in Humidified air?

- what is the pCO2 in Alveolar air?

Back 16

~ Zero (0.03) = 0.04%

40 mmHg = ~5%

Front 17

N2K REVIEW

- what is the pO2 in Humidified air?

- what is the pO2 in Alveolar air?

Back 17

149.3 mmHg (~20%)

104 mmHg (~14%)

Front 18

ALVEOLAR AIR

- what is the FRC?

- but how much is brought in with each resting breath?

- above is considered to the rate of what?

Back 18

FRC = 2300 mL

350 mL brought in with each resting breath

Rate of Alveolar renewal

Front 19

ALVEOLAR AIR

- how many successive breaths would bring to equilibrium the excess of gas?

Back 19

- 16 breaths

Front 20

N2K REVIEW

- what is the Alveolar Respiratory Rate?

Back 20

(Vd - Dead space) x Respiratory rate

= (500 mL - 150 mL) x 12

= 4200 mL

Front 21

ALVEOLAR AIR

- Normal Alveolar Ventilation occurs when?

- Twice the normal Alveolar Ventilation occurs when?

- Half the normal Alveolar Ventilation occurs when?

Back 21

- Rest

- Exercise

- Sleep

Front 22

ALVEOLAR AIR

- over time, describe the Alveolar Ventilation rate

(rate at which alveolar air is renewed)

Back 22

- exponential decrease seen within 1 min

(slow replacement)

Front 23

ALVEOLAR AIR

- what makes the respiratory control mechanism work more smoothly?

Back 23

- Slow replacement

Front 24

ALVEOLAR AIR

- in calculating the alveolar respiration rate, what would change for an individual who is larger?

Back 24

- Dead space goes up

Front 25

ALVEOLAR AIR

- what isthe O2 consumption (absorption) at rest?

- what about during exercise?

Back 25

250 mL O2 / min

1000 mL O2 / min

Front 26

ALVEOLAR AIR

- what is the CO2 consumption (absorption) at rest?

- what about during exercise?

Back 26

200 mL CO2 / min

800 mL CO2 / min

Front 27

ALVEOLAR AIR

- during exercise, O2 consumption (alveolar absorption) changes how?

- what about with CO2?

- what values stay the same? x2

- thus, what must change and how?

Back 27

Quadruples (250 to 1000)

Quadruples (200 to 800)

- partial pressure of Alveolar pO2
- partial pressure of Alveolar pCO2

- Alveolar ventilation
(goes up...almost quadrupled)

Front 28

ALVEOLAR AIR

- which curve is steeper, O2 consumption or CO2 consumption?

- what is the rate limiting step in the O2 curve?

Back 28

- CO2 consumption

- O2 diffusion

Front 29

ALVEOLAR AIR

T/F : Expelling CO2 is the rate limiting step in CO2 consumption curve

Back 29

- False

- Ventilation rate is controlled by your need for O2, not CO2

Front 30

EXPIRED AIR

- Alveolar pO2 in Expired air is?

- Alveolar pCO2 in Expired air is?

Back 30

104

40

Front 31

N2K REVIEW

- partial pressure values for Dead space is roughly equal to?

Back 31

- outside world
(humidified air)

Front 32

N2K REVIEW

- partial pressure values for O2. x3

(humidified, alveolar, and expired air)

Back 32

Humidified Air = 149 mmHg

Alveolar Air = 104 mmHg

Expired Air = 120 mm Hg

Front 33

N2K REVIEW

- partial pressure values for CO2? x3

(humidified, alveolar, and expired air)

Back 33

Humidified Air = 0 mmHg

Alveolar Air = 40 mmHg

Expired Air = 27 mm Hg

Front 34

RESPIRATORY LOBULE

- Terminal Bronchiole divides into?

- which divides into?

- which divides into?

- which divides into?

Back 34

- Respiratory Bronchiole

- Alveolar Duct

- Alveoli

- Alveolar Sac

Front 35

RESPIRATORY LOBULE

- blood flow is like a "sheet" where?

- why?

Back 35

- in the pulmonary capillaries

- b/c there are so many and so close to each other

Front 36

RESPIRATORY MEMBRANE

- list the 6 layers of the Respiratory membrane in order

Back 36

(AA ET CC)

- Alveolar Fluid (incl. surfactant)
- Alveolar Epithelium

- Epithelial Basement Membrane
- Thin Interstitial Space

- Capillary Basement Membrane
- Capillary ENDOThelium

Front 37

RESPIRATORY MEMBRANE

- respiratory epithelium is thin or thick?

- average thickness? except over what?

Back 37

- thin

- 0.6 micrometers
- except over nucleus

Front 38

RESPIRATORY MEMBRANE

- Total surface area in average adult is?

Back 38

70 square meters

Front 39

RESPIRATORY MEMBRANE

- Total Quantity of Blood in Capillary Bed?

- Average Diameter of respiratory Capillary?

Back 39

60 to 140 mL

5 micrometers

Front 40

RESPIRATORY MEMBRANE

- average diameter of Respiratory Capillary?

- average diamter of RBC?

Back 40

5 micrometers

7 micrometers

Front 41

RESPIRATORY MEMBRANE

- what is the significance of the fact that the respiratory capillary diameter is smaller than the RBC diameter?

Back 41

- RBC has to squeeze through

- thus rubs up against the endothelium

- provides good way for exchange

Front 42

RESPIRATORY MEMBRANE

- when the RBC squeezes through the respiratory capillary for gas exchange, what are the involved players?

Back 42

(P STD)

- Pressure difference

- Surface area
- Thickness of membrane
- Diffusion coefficient

Front 43

RESPIRATORY MEMBRANE

- Diffusing capacity of Respiratory membrane increases during?

- due to? x2

Back 43

- Exercise

- Opening more capillaries
or
- Dilating more capillaries

Front 44

RESPIRATORY MEMBRANE

- During exercise, with the increase in Diffusing capacity, what else is Improved?

Back 44

- Ventilation-Perfusion ratio

Front 45

VENTILATION-PERFUSION RATIO

- if the V/Q ratio is normal in Alveoli, what are the values seen? x2

- if the V/Q ratio approaches Zero, then is that normal? if so then where?

- if the V/Q ratio approaches infinite, then is that normal? if so, then where?

Back 45

- pO2 = 104
- pCO2 = 40

- normal in Venous blood
(pO2 = 40 , pCO2 = 45)

- normal in Inspired air
(pO2 = 149, pCO2 = 0)

Front 46

"PHYSIOLOGIC SHUNT"

- the greater the physiologic shunt, the greater the what?

Back 46

- amount of blood that Fails to be oxygenated
(means greater failure of ventilation)

(as it passes thru lungs)

Front 47

"PHYSIOLOGIC SHUNT"

- what is the V/Q ratio in the physiologic shunt?

Back 47

- Zero

(Ventilation is Zero)
(Perfusion or Blood Flow is normal)

Front 48

"PHYSIOLOGIC SHUNT"

- give an example of a physiologic shunt.

- what is the Ventilation value here?
- what is the Perfusion value here?

- what is the Arterial pO2 here?
- what is the Arterial pCO2 here?

Back 48

- steak caught in trachea

- Zero ventilation
- Normal Perfusion

40 mmHg
45 mmHg

Front 49

"PHYSIOLOGIC SHUNT"

- is there gas exchange in a lung that is perfused but not ventilated?

- what are the partial pressure values in the Alveoli?

Back 49

- no

- none

Front 50

"PHYSIOLOGIC SHUNT"

- what is the equation to solve for "Physiologic shunt"

Back 50

Front 51

"PHYSIOLOGIC DEAD SPACE"

- when "Physiologic Dead Space" is great, much of the work of Ventilation is what?

- why?

Back 51

- Wasted effort

- Much of Ventilated Air NEVER reaches the blood

Front 52

"PHYSIOLOGIC DEAD SPACE"

- what is the name of the equation used to solve for "physiologic dead space"

- give the equation

Back 52

Front 53

"PHYSIOLOGIC DEAD SPACE"

- what is the V/Q ratio here?

- value for Ventilation
- value for Perfusion

Back 53

- infinite
(same as normal inspired air)

- normal
- none

Front 54

"PHYSIOLOGIC DEAD SPACE"

- what is the Alveolar pO2?
- what is the Alveolar pCO2?

- what is the Arterial pO2?
- what is the Arterial pCO2?

Back 54

149
zero

none
none

Front 55

"PHYSIOLOGIC DEAD SPACE"

- If there is ventilation but no perfusion, is there gas exchange?

Back 55

- none

Front 56

N2K REVIEW
"PHYSIOLOGIC SHUNT"

- what is V/Q ratio in "physiologic shunt"

- what is Ventilation value?
- what is Perfusion value?

- what is gas exchange value?

Back 56

- Zero

- Zero
- Normal

- None

Front 57

N2K REVIEW
"PHYSIOLOGIC SHUNT"

- what is the Alveolar pO2 ?
- what is the Alveolar pCO2 ?

- what is the Arterial pO2 ?
- what is the Arterial pCO2 ?

Back 57

- none (b/c no ventilation)
- none (b/c no ventilation)

40 mmHg
45 mmHg

Front 58

N2K REVIEW
"PHYSIOLOGIC SHUNT"

- which partial pressure values for pO2 and pCO2 have actual values?

- these will approach their values where?

Back 58

- Arterial (b/c no ventilation)

- Mixed blood

Front 59

N2K REVIEW
"PHYSIOLOGIC DEAD SPACE"

- what is V/Q ratio in "physiologic dead space"

- what is Ventilation value?
- what is Perfusion value?

- what is gas exchange value?

Back 59

- infinite

- normal
- none

- none

Front 60

N2K REVIEW
"PHYSIOLOGIC DEAD SPACE"

- what is the Alveolar pO2 ?
- what is the Alveolar pCO2 ?

- what is the Arterial pO2 ?
- what is the Arterial pCO2 ?

Back 60

- 150 mmHg
- Zero

- none
- none

Front 61

N2K REVIEW
"PHYSIOLOGIC DEAD SPACE"

- which partial pressure values for pO2 and pCO2 have actual values?

- these will approach their values where?

Back 61

- Alveolar (b/c dead space = no blood flow or perfusion)

- Normal Inspired Air

Front 62

N2K REVIEW
NORMAL V/Q RATIO

- if the V/Q is normal, then it is equal to what?

- what is the Alveolar pO2 ?
- what is the Alveolar pCO2 ?

- what is the Arterial pO2 ?
- what is the Arterial pCO2 ?

Back 62

- Normal alveolar air

- 104 mmHg
- 40 mmHg

- 104 mmHg
- 40 mmHg

Front 63

ZONES

- Zone 1 Ventilation?
- Zone 1 Perfusion?

- why?

Back 63

- Normal

- No perfusion (no flow)

- Alveolar Press. > Arterial Press.

Front 64

ZONES

- Zone 2 Ventilation?
- Zone 2 Perfusion?

- why?

Back 64

- Constant

- Intermittent

- SYSTOLIC Arterial Press. > Alveolar Press.
&
- DIASTOLIC Arterial Press. < Alveolar Press.

Front 65

ZONES

- Zone 3 Ventilation?
- Zone 3 Perfusion?

- why?

Back 65

- Normal
- Normal or Continuous

- Arterial Press. > Alveolar Press.

Front 66

ZONES

- Blood flow (Perfusion) is highest at?

- Blood flow (Perfusion) is lowest at?

Back 66

- base

- apex

Front 67

ZONES

- Ventilation is highest at?

- Ventilation is lowest at?

Back 67

- apex

- base.

Front 68

ZONES

- Graphically, when you see lines of Ventilation & Perfusion cross, it implies what?

- Graphically, it can be seen that the V/Q Ratio changes how as it goes down the lung (increasing rib #)?

Back 68

- Normal V/Q ratio

- Decreases V/Q ratio
(b/c the lower you go, the less ventilation you get)

Front 69

ZONES

- V/Q ratio at the Apex results in a high partial pressure of what?

- V/Q ratio at the Apex results in a low partial pressure of what?

- V/Q ratio at the Base results in a high partial pressure of what?

- V/Q ratio at the Base results in a low partial pressure of what?

Back 69

APEX
- pO2 high
- pCO2 low

- pCO2 high
- pO2 low

Front 70

V/Q RATIO ABNORMALITIES

- in a normal person under resting conditions, you would find some Physiologic Dead Space where?

- what about finding some Physiologic Shunt?

- Both would disappear under what conditions?

Back 70

- Apex of lung

- Base of Lung

- Exercise

Front 71

V/Q RATIO ABNORMALITIES

- in chronic obstructive lung disease caused by smoking and emphysema, physiologic shunt can result due to what?

Back 71

- Obstruction of many Small Bronchioles

- thus leaving subsequent Alveoli UNVentilated

Front 72

V/Q RATIO ABNORMALITIES

- in chronic obstructive lung disease caused by smoking and emphysema, physiologic dead space can increase due to what?

Back 72

- Alveolar wall of many lung areas are destroyed

Front 73

V/Q RATIO ABNORMALITIES

- in chronic obstructive lung disease caused by smoking and emphysema, both physiologic shunt and physiologic dead space, will seriously inhibit what?

- to what degree

Back 73

- Effiectiveness of lungs

- drops to 1/10 of normal sometimes