Quiz 5 Transport of Oxygen & Carbon Dioxide Flashcards Preview

GNURS627/Respiration/Physiology for Anesthesa > Quiz 5 Transport of Oxygen & Carbon Dioxide > Flashcards

Flashcards in Quiz 5 Transport of Oxygen & Carbon Dioxide Deck (42):
1

What is the tissue pressure for O2 at the capillaries?

PO2 > 10 mm Hg

2

What is the tissue pressure for CO2 at the Capillaries?

PCO2 > 50 mm Hg

3

Diffusion is too slow over what distance?

> 100 um

4

What is hypoxic hypoxia?

-inadequate O2 uptake into blood in lungs
-Chronic obstructive pulmonary disease

5

What is stagnant (ischemic) hypoxia?

-inadequate blood flow to an organ
-Arteriosclerosis peripheral vascular disease

6

What is anemic hypoxia?

-Inadequate blood oxygen carrying capacity
-Inactivated hemoglobin

7

What is histotoxic hypoxia?

-Interference with mitochondrial respiration
-Cyanide poisoning

8

What is diffusion disturbance?

-Long diffusion path

9

What is the normal hemoglobin concentration?

-15 g/dL or 150 g/L

10

What are the four subunits of hemoglobin?

-2 alpha
-2 beta

Normal adult HgbA has both A2 + B2

11

How much O2 can be carried by each gram of hemoglobin?

-1.31 mL of O2 (theoretically up to 1.39 mL/gm)

12

T/F: Hemoglobin is oxygenated.

False

13

T/F: Oxyhemoglobin is oxygenated.

True

14

What is oxygen saturation?

Ratio of oxygen bound to Hb compared to total amount that can be bound.

15

What is oxygen capacity?

Maximal amount of O2 bound to Hemoglobin.

16

What is the PaO2 when saturation (Hb) is 90%?

PaO2 = 60

17

What is the PaO2 when the saturation (Hb) is 75%?

PaO2 =40

18

What is the Pa02 when the saturation (Hb) is 50%?

PaO2 = 27

19

What is Ligand of hemoglobin?

-covalent bonds to the iron in Hemoglobin
-the bonds have more affinity to iron in hemoglobin than does oxygen

20

Carbon monoxide binds ______ times stronger to hemoglobin than oxygen.

-250 times the affinity then oxygen
-does not dissociate readily
-Requires hours to rid body of CO

21

Nitric oxide binds ______ times stronger to hemoglobin than oxygen.

-200,000 times the affinity then oxygen
-hemoglobin binds irreversibly to NO
-Used to treat hypertension

22

What factors would create a left shift of the Hb-O2 dissociation curve?

-Low PCO2 (alkalosis)
-Low temperature
-Low levels of 2,3 DPG
-carboxyhemoglobin
-methemoglobin
-abnormal hemoglobin

23

What factors would create a right shift of the Hb-O2 dissociation curve?

-Acute acidosis
-High CO2
-Increased temperature
-High levels of 2, 3 DGP
-Abnormal hemoglobin

24

What type of shift would you see on Hb-O2 disassociation curve after a blood transfusion?

A left shift - PRBC are stored cold and are low in 2,3 DPG

25

Packed red blood cells have a diminished level of what?

2,3 DPG

26

What is the normal CO2 production in a resting adult?

200 mL/min

27

What are the three forms carbon dioxide is transported by the blood?

1. Dissolved directly in blood.
2. Bicarbonate ion (HCO3-) and Carbonic acid (H2CO3).
3. Bound to hemoglobin and plasma proteins.

28

In what form is most CO2 transported by in the blood?

-Bicarbonate (HCO3-)

29

What is the P50 of oxygen PO2?

P50 - the pressure of Oxygen PO2 when your hgb is 50% saturated.
P50 = 27mmHg

30

Venous hgb has a PO2 of 40mm Hg, what is it's O2 Sat?

approx 75%

31

If you have a change in shape of the S-curve of the Oxyhemoglobin Curve, what does this indicate?

greater interference with O2 transport than a shift in the curve

32

Which has a greater affinity for oxygen, hemoglobin or myoglobin?

Myoglobin - binds O2 at lower PO2

33

What is Bohr effect?

An increase in H+ decreases Hgb's affinity for O2 (right shift)

34

What is the equation for CaO2 (O2 content of the blood)?

CaO2 = (SO2 * Hgb * 1.31) + (PO2 * 0.003)

SO2 will be expressed as decimal rather than %

35

In the equation for CaO2, what does the 1.31 represent?

the amount of O2 (1.31 ml) that 1 gm of Hgb can carry.

36

What is the Haldane effect?

O2 binds to Hgb --> Hgb releases CO2 and H+

37

What is the rough way to estimate PaO2 to SaO2?

PaO2: 40,50,60 ~ SaO2 70,80,90 %

38

Give an example of Hypoxic Hypoxia

COPD

39

Give an example of Stagnant (ischemic) hypoxia

Arteriosclerosis, PVD

40

Give an example of Anemic Hypoxia

hypoxia due to anemia - inactivated hemoglobin.

41

Give an example of Histotoxic Hypoxia

hypoxia due to cyanide poisoning

42

How many oxygen molecules can bind to a single hemoglobin?

4