B4-035 O2 and CO2 Transport

Question 1

CO2 diffuses [….] than O2

Answer 1

more readily

Question 2

perfusion or diffusion limited?

gas equilibrates early along the length of the capillary

Answer 2

perfusion limited

Question 3

perfusion or diffusion limited?

exchange can only be increased if blood flood increases

Answer 3

perfusion limited

Question 4

perfusion or diffusion limited?

O2 (normal health), CO2, N2O

Answer 4

perfusion limited

Question 5

perfusion or diffusion limited?

gas does not equilibriate by the time blood reaches the end of the capillary

Answer 5

diffusion limited

Question 6

perfusion or diffusion limited?

O2 (empysema, fibrosis) CO

Answer 6

diffusion limited

Question 7

O2 diffuses […] across the alveolar membrane

Answer 7

slowly

Question 8

CO2 diffuses […] across the cell membrane

Answer 8

rapidly

Question 9

dissolved oxygen contributes to the […] of oxygen in blood

Answer 9

partial pressure

Question 10

[…] dictates hemoglobin/O2 characteristics

Answer 10

partial pressure of oxygen in blood

Question 11

very little O2 is carried in the […]form

Answer 11

dissolved

Question 12

• partial pressure of O2 in blood
• determined by molecules of O2 contained in the liquid phase

Answer 12

blood PO2

Question 13

right shift of curve results in

Answer 13

more oxygen being unloaded where needed

Question 14

left shift of curve indicates

Answer 14

more O2 saturation to carry oxygen where its needed

Question 15

downward shift of curve indcates

Answer 15

change in Hemoglobin amount

Question 16

upward shift of curve indicates

Answer 16

increase in dissolved PO2

Question 17

a-v O2 difference reflects

Answer 17

oxygen consumption by the body

Question 18

three forms of CO2 in blood

Answer 18

HCO3-
HbCO2
dissolved

Question 19

as CO2 enters the blood […] leaves O2

Answer 19

hemoglobin

Question 20

in lungs, oxygenation of Hb promotes dissociation of

Answer 20

H+

shifts equilibrium toward CO2 formation

Question 21

in lungs, oxygenation of Hb promotes H+ dissociation, CO2 is

Answer 21

released from RBCs

Question 22

causes decreased transit time through capillaries

Answer 22

exercise

Question 23

pressure gradient of […] is much higher

Answer 23

O2

Question 24

pressure gradient of […] is lower

Answer 24

CO2

10x less than O2

Question 25

a thicker capillary membrane will have a greater effect on [...] diffusion

Answer 25

O2

Question 26

oxygen has a more difficult time diffusing across the membrane due to the

Answer 26

high pressure gradient

Question 27

a severe reduction in PaO2 will trigger compensatory

Answer 27

hyperventilation

Question 28

factors that effect DLO2

Answer 28

* surface area available for diffusion * distance from alveolus to RBC

Question 29

an increase in the capillary membrane thickness can be detected by

Answer 29

testing the diffusing capacity of CO

Question 30

PO2 of 45mm Hg is a Hb saturation of

Answer 30

75%

Question 31

PO2 of 100 mmHg is a Hb saturation of

Answer 31

95%

Question 32

normal O2 content in blood

Answer 32

20 ml/dl

Question 33

higher than normal hemoglobin is a compensatory mechanism for

Answer 33

long term hypoxia will still have normal O2 content, even though Hb saturation is low

Question 34

PPL at end of expiration at FRC is

Answer 34

-5 cm H2O

Question 35

a less negative PPL indicates

Answer 35

reduced elastic recoil | high compliance

Question 36

increased compliance means easy to

Answer 36

inflate | less elastic recoil

Question 37

hypoxia causes pulmonary arterial

Answer 37

vasocontriction

Question 38

increasing arterial blood PO2 only affects

Answer 38

dissolved O2, minimal change in graph

Question 39

arterio-venous O2 difference is affected by

Answer 39

O2 consumption in the tissues

Question 40

a decreased in PCO2 would signal

Answer 40

hyperventilation

Question 41

breathing 100% O2 causes a several fold increase in

Answer 41

PaO2

Question 42

if cardiac ouput and O2 consumption remain unchanged, the arterio-venous O2 difference

Answer 42

remains unchanged

Question 43

Fick Principle

Answer 43

VO2=Q x (CaO2-CvO2)

Question 44

how would anemia alter the PO2 and the total O2 content?

Answer 44

PO2 remains normal Total O2 content is low | Hb is well oxygenated, just not enough Hb

Question 45

will mild/moderate anemia increase ventilation?

Answer 45

no, PO2 is normal so chemoreceptors do not fire

Question 46

if lung function is normal, the difference between alveolar and arterial PO2 is

Answer 46

5-10 mmHg

Question 47

O2 carrying capacity is determined by | 2

Answer 47

1. Hb concentration 2. O2 affinity

Question 48

PCO2 at normal alveolar ventilation

Answer 48

40 mmHg

Question 49

PCO2 of >40 mmHg indicates

Answer 49

hypoventilation