RS Lec 6

Question 1

O2 in blood forms

Answer 1

• dissolved (2%)

- combined with hemoglobin (98%)

Question 2

dissolved O2 proportional to (2)

Answer 2

PO2

solubility

Question 3

98% (197 ml/L) of O2 carried on

Answer 3

hemoglobin in red blood cells

Question 4

hemoglobin made of

Answer 4

• globins: 4 subunits (a.a) - 2 alpha/ 2 beta

- 4 heme groups

Question 5

heme (def.)

Answer 5

porphyrin ring structure that has Fe2+ that O2 binds

Question 6

each HB molecule can bind

Answer 6

4 O2- one per subunit (O2 + Hb HbO2)

Question 7

Hb

Answer 7

deoxyhemoglobin

Question 8

HbO2

Answer 8

oxyhemoglobin

Question 9

O2 capacity

Answer 9

max amount of O2 that is combined with Hb

Question 10

1 g Hb combines with (amount of O2)

Answer 10

1.39 ml O2

Question 11

normal conditions (g Hb/ 100 ml blood)

Answer 11

15g Hb/100 ml

Question 12

max O2 capacity (g Hb/100 ml)

Answer 12

20.8 ml O2/100 ml blood

Question 13

Hb saturation

Answer 13

• percentage of available Hb binding sites that have O2 attached
• O2 with Hb/ O2 capacity x 100%

Question 14

Hb saturation of arterial blood (100 mmHg PO2)

Answer 14

97.5%

Question 15

Hb saturation of mixed venous blood (40 mmHg PO2)

Answer 15

75%

Question 16

factors that determine Hb saturation

Answer 16

• arterial PO2 (most important)

- cooperative binding (sigmoidal dissociation curve)

Question 17

dissociation curve sensitive to

Answer 17

• pH
• pCO2
• temp.

Question 18

cooperative binding

Answer 18

O2 binding causes change from T (tense) to R (relaxed) state in a globin, facilitates change in other globin and additional O2 binding

Question 19

plateau in dissociation curve

Answer 19

60-100 mmHg

Question 20

plateau in dissociation curve can indicate

Answer 20

reduced arterial PO2 (therefore reduced alveolar PO2

Question 21

plateau in dissociation curve (saturation drop)

Answer 21

10 % over 100 to 60 mmHg of PO2

Question 22

steep portion in dissociation curve

Answer 22

40 - 60 mmHg

Question 23

steep portion in dissociation curve unload

Answer 23

large amounts of oxygen with small decrease in PO2

Question 24

steep portion in dissociation curve changes leads to

Answer 24

changes in O2 unloading by the binding of compounds produced in peripheral tissue

Question 25

increases metabolic rate facilitates

Answer 25

diffusion from plasma leading to a drop in plasma PO2

Question 26

anemia

Answer 26

reduction in Hb amount in blood

Question 27

polycythemia

Answer 27

increase of Hb amount in blood or reduction of blood volume that increases Hb concentration

Question 28

carbon monoxide affinity for Hb compared to O2

Answer 28

200x

Question 29

carbon monoxide effects on HB

Answer 29

- reduction in O2-Hb binding - shift to the left in curve (no sigmoidal curve). - decrease of unloading of O2 to tissue

Question 30

pH changes effects on curve

Answer 30

increase pH=shift to left

Question 31

temp changes effects on curve

Answer 31

increase temp=shift to right

Question 32

PCO2 changes effects on curve

Answer 32

increase PCO2=shift to right

Question 33

DPG (2,3 diphosphoglycerate) is

Answer 33

an end product of RBC metabolism

Question 34

DPG changes effects on curve

Answer 34

shift to right

Question 35

changes to the right (on the curve)

Answer 35

O2 affinity of Hb is reduced = more unloading

Question 36

changes to the left (on the curve)

Answer 36

O2 affinity of Hb is increased = less unloading

Question 37

3 forms that carbon dioxide exist in the blood

Answer 37

- dissolved (5%) - HCO3- (60-65%) - carbamino compounds (25-30%)

Question 38

CO2 solubility is high

Answer 38

- 0.067 ml CO2/100 ml blood (each mmHg) | - @ 40 mmHg 2.68 ml CO2/ 100 ml blood

Question 39

CO2 and Hb (affinity)

Answer 39

deoxyHb has higher affinity or CO2 compared to OxyHb

Question 40

Hb buffers pH of blood

Answer 40

H+bounded to Hb and not dissolved in RBC/plasma | -deoxyHb has a higher affinity for H+ compared to OxyHb

Question 41

Hypoventilation (CO2 production > CO2 elimination)

Answer 41

PCO2/H+ increase

Question 42

Hyperventilation (CO2 production < CO2 elimination)

Answer 42

PCO2/ H+ decrease

Question 43

respiratory acidosis

Answer 43

increase in blood H+ concentration dependent on changes in PCO2

Question 44

metabolic acidosis

Answer 44

increase in blood H+ concentration independent on changes in PCO2

Question 45

respiratory alkalosis

Answer 45

decrease in blood H+ concentration dependent on changes in PCO2

Question 46

metabolic alkalosis

Answer 46

decrease in blood H+ concentration independent on changes in PCO2