Exam Ii - Adv Pathophys - Transport Of O2 And Co2 In Blood And Tissue

Front 1

Once oxygen has diffused from the alveoli into the pulmonary blood it is then transported to the

Back 1

peripheral tissue capillaries

Front 2

The overwhelming majority of the oxygen is carried by the

Back 2

hemoglobin or in bound form

Front 3

Only a small portion of the the oxygen is transported in the

Back 3

unbound form

Front 4

What is the path O2 takes via diffusion gradients

Back 4

alveoli to pulmonary capillary blood to tissue

Front 5

Oxygen diffuses from the alveoli into the pulmonary capillary blood because

Back 5

The alveoli PO2 is greater than the pulmonary capillary blood PO2

Front 6

Oxygen diffuses out of the pulmonary capillary blood into the tissue because

Back 6

The pulmonary capillary blood PO2 is greater than the tissue PO2

Front 7

When O2 is metabolized and CO2 is formed

Back 7

basically the opposite of O2 - CO2 has to work from the intracellular to the alveoli

Front 8

CO2 diffuses into the capillary blood because

Back 8

the intracellular PCO2 is higher than the capillary blood PCO2

Front 9

CO2 diffuses from the capillary blood to the alveoli because the

Back 9

capillary blood PCO2 is higher than the alveoli PCO2

Front 10

What actions have a 20 year SOL?

Back 10

-Enforcement on judgment
-Action by NYS to recover real prop.

Front 11

The PO2 of the venous blood entering the pulmonary capillary averages

Back 11

40torr

Front 12

As pulmonary capillary blood passes the alveolar, as it reaches the venous end it reaches pressures of about

Back 12

104torr (nearly the same as the alveolar PO2)

Front 13

During strenuous exercise, the human body's requirements may increase as much as

Back 13

20x

Front 14

Why does increase in cardiac output during exercise cuts the time blood remains in the pulmonary capillary

Back 14

blood is traveling faster

Front 15

How does body meet increase in demand from exercise

Back 15

1. increased surface area for diffusion - entire lung V:Q rations improve
2. Since blood in resting condition stays in pulmonary capillary 3x longer than needed, there is still ample time for oxygen to meet equilibrium

Front 16

How much of the blood that enters the left atrium has passes through the alveolar capillaries

Back 16

98%

Front 17

Blood that bypasses the alveolar capillaries is called

Back 17

shunted blood

Front 18

Unoxygenated blood has a PO2 of

Back 18

40torr

Front 19

When admixture occurs, PO2 of blood entering left atrium lowers to

Back 19

95torr

Front 20

Blood reaching the tissue capillaries has a PO2 of

Back 20

95torr

Front 21

The interstitial fluid has a PO2 of

Back 21

40torr

Front 22

As blood travels through the capillary system towards the venous end, exchange occurs and venous capillary blood has PO2 of

Back 22

40torr

Front 23

Does supply affect the interstitial fluid PO2

Back 23

yes

Front 24

If blood flow to a tissue increases (increased supply)

Back 24

greater quantities of O2 are transported into the tissue and tissue O2 becomes greater

Front 25

Explain in part how vasoconstriction can lead to tissue hypoxia

Back 25

as demand increases - but there is a leveling off of the amount of oxygen than can enter the tissue because the gradient is narrowing - the maximum PO2 would be what's in the blood - 95torr
look at page 8

Front 26

Does demand impact tissue oxygen

Back 26

yes

Front 27

How does demand impact tissue oxygen

Back 27

As the demand for oxygen by the cells increases the amount of interstitial oxygen is decreases - this increases the gradient between the interstitial O2 and capillary O2 - thus the venous capillary O2 is reduced (seen in SVO2)

Front 28

Intracellular PO2 range

Back 28

5-40torr or avg 23torr

Front 29

How much intracellular PO2 is required to support function

Back 29

1-3torr

Front 30

Why is having a minimum intracellular PO2 of 1-3torr important

Back 30

it provides a huge safety margin

Front 31

Why is there a discrepancy/range of intracellular PO2

Back 31

because of the distance from capillaries

Front 32

Oxygen used by the cell generates

Back 32

CO2

Front 33

At the lung level, the high venous capillary CO2 sets up a

Back 33

gradient where the CO2 diffuses into the alveoli

Front 34

What is one major difference between O2 and CO2

Back 34

CO2 diffuses 20x faster than O2

Front 35

The intracellular CO2 is approx

Back 35

46torr

Front 36

How much of a difference in pressure is there between intracellular and interstitial/venous CO2

Back 36

only 1torr

Front 37

Arterial CO2 is

Back 37

40torr

Front 38

In the pulmonary system blood enters with a CO2 of ____ and leaves with a CO2 of ____

Back 38

45torr, 40torr

Front 39

As with O2, CO2 makes entire alveolus-capillary exchange within the first

Back 39

1/3 of capillary

Front 40

How much oxygen is bound to HGB

Back 40

97%

Front 41

How much oxygen is dissolved in plasma

Back 41

3%

Front 42

Systemic blood saturation averages

Back 42

97%

Front 43

Venous blood saturation averages

Back 43

75%

Front 44

Based on carrying capacity formula the most oxygen can carry is

Back 44

1.34ml x the HGB

Front 45

Typically the most oxygen hemoglobin is

Back 45

20.1ml/dl

Front 46

Factors that shift oxyhemoglobin curve to the left

Back 46

decreased CO2
increased pH
decreased blood temp
decreased 2,3 DPG

Front 47

Increased PaCO2 at the tissue level would shift the oxyhemoglobin curve left or right

Back 47

right

Front 48

Increased PaCO2 at the tissue level would it cause a change in oxygen loading or unloading

Back 48

unloading

Front 49

Decreased PaCO2 at the alveolar level would shift the oxyhemoglobin curve left or right

Back 49

left

Front 50

Decreased PaCO2 at the tissue level would it cause a change in oxygen loading or unloading

Back 50

loading

Front 51

The see saw effect of the oxyhemoglobin curve in response to CO2 and pH is called the

Back 51

Bohr effect

Front 52

As tissue produces CO2 - which enters the capillary blood - which causes a increase in amount of hydrogen ions shifts the curve to the

Back 52

right -

Front 53

At the lung, the CO2 diffuses into the alveoli reducing the CO2 and decreases the H+ concentration - this shifts the curve to the

Back 53

left - unloading oxygen

Front 54

What is 2,3 DPG

Back 54

diphosphoglycerate

Front 55

2,3 DPG keeps the curve shifted to the

Back 55

right with hypoxia - favoring unloading at the tissue

Front 56

2,3 DPG increases considerably in hypoxic conditions that last

Back 56

more than a few seconds to hours

Front 57

2,3 DPG is a

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protective mechanism to maintain organs

Front 58

CO has what affinity for hemoglobin

Back 58

250x

Front 59

With CO, does PaO2 change

Back 59

no because unbound

Front 60

What is tx for CO poisoning

Back 60

increased FiO2 - fights for place on HGB
hyperbaric chamber - increased gradient

Front 61

On average, how much CO2 is transported from tissue per dl

Back 61

4ml/dl

Front 62

Body makes how much CO2 per minute

Back 62

250ml

Front 63

Three ways CO2 is transported

Back 63

1. dissolved in blood - PaCO2 - 7%
2. as part of carbonic acid as part of buffer system
3. carbaminohemoglobin - reacts with amino radicals of HGB and plasma proteins forming loose bonds - 23%

Front 64

CO2 combines with H2O to form H2CO3 in the presence of carbonic anhydrase. The dissociated H+ combine with HGB - what happens to HCO3

Back 64

HCO3 is transported out of the RBC in exchange for Cl- ions by a powerful bicarb/chloride carrier protein - this is called the chloride shift

Front 65

What is a primary way CO2 is carried in the blood

Back 65

the CO2 + H2O --> H2CO3 --> H+ + HCO3 (exchanged for Cl-)

Front 66

What changes the affinity for O2

Back 66

Bohr effect

Front 67

Haldane effect is

Back 67

the displacement of CO2 from the HGB for O2 - directly impacts the transport of CO2

Front 68

O2 combining with HGB causes the HGB to to become a

Back 68

stronger acid

Front 69

Explain the Haldane effect

Back 69

O2 combining with HGB causes the HGB to to become a stronger acid - this in turn prevents CO2 from combining to the amino radicals - pushing the CO2 into the plasma and the acidity of of the HGB causes it to release H+, which combines with HCO3 in the plasma, dissociates at the lungs

Front 70

Haldane effect directly impacts the transport of

Back 70

CO2

Front 71

Why is the haldane effect a great thing

Back 71

at the issue, oxygen levels frip - based on the haldane effect the HGB becomes more acidic allowing for more CO2 pickup - at the lungs the O2 loads creating an acidic HGB which in turns causes the CO2 to move out of the HGB

Front 72

Which is more important Bohr or haldane

Back 72

Haldane effect