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Flashcards in Test 2 Deck (88):
1

Blood accounts for how much of TBW

8%

2

Whole blood percentage by volume

Plasma

Formed elements

Plasma 55%

Formed elements 45%

3

4 functions of RBCs

Transport O2 via heme portion of Hgb

Transport CO2 via globin portion of Hgb

Contain enzyme carbonic anhydrosis

Acid-base buffer to regulate pH

4

Formula for CO2 to HCO3

CO2+H20. Add carboic anhydrase = H2CO3 breaks down into H + HCO3

5

Each gram of Hgb can combine with and transport how much O2

1.34ml

6

Prenatal production of RBCs

Liver, spleen, lymph nodes

7

Birth to 5 yrs production of RBCs

Bone marrow

8

After 20 yrs production of RBCs

Bone marrow

Primarily vertebrae, sternum, and ilium

9

Common ancestor to all formed elements of blood

Stem cell

Pleuropotential hematopetic stem cell

10

What determines the path stem cells take

Differentiating factors

11

Maturation of stem cell to RBC

Stem cell - proerythroblast -
Early erythroblast-
Intermediate erythroblast-
Late erythroblast-
Reticulocyte-
RBC

12

When is nucleus extruded in development of RBC

From late erythroblast to Reticulocyte

Also when cell moves into blood

13

Lifespan of mature RBC

120 days

14

RBC produces ATP via

Anaerobic metabolism (glycolysis)

15

ATP yield of anaerobic metabolism

Gross 4 ATP

Net 2 ATP

16

Do RBC contain ribosomes? Implication

No. Cannot make enzymes. All enzymes have to be created by bone marrow during development

17

High Reticulocyte count causes

Normal physiologic response to hemorrhage

18

RBC production is regulated by

Erythropoetin

19

90% of erythropoetin produced where

Peritubular epithelial cells

20

EPO is produced in response to

Hypoxia of the cells that secrete EPO

21

EPO function

Stimulates pro erythroblasts and causes them to proceed through development more rapidly

22

As RBC increase and hypoxia decreases, what decreases EPO secretion

Negative feedback system

23

2 maturation factors for RBCs

Vitamin B12 (cobalamin)

Folic Acid (folate)

24

Insufficient vitamin B12 results in

RBC maturation failure and abnormally large RBCs

25

Anemia’s caused by Vitamin B12 deficit

Megaloblastic Anemia

Macrocytic Anemia

Pernicious Anemia

26

The abnormally large RBCs results in

Abnormal oxygen transport

Easy hemolysis

27

Vitamin B12 is an ______ factor

Meaning

Extrinsic factor

Have to take in from outside the body

28

Vitamin B12 must bind with intrinsic factor secreted by

Gastric parietal cells

29

Vitamin B12 bound with intrinsic factor is absorbed from

Ileum

30

Causes of Vitamin B12 deficiency and anemia

Inadequate dietary intake
- uninformed vegetarians

Atrophy of gastric mucousa and inadequate intrinsic factor secretion

Gastric bypass or gastric reduction procedures

Small bowel resection, esp ileum

Malabsorption syndromes of small bowel

31

Causes of folic acid deficiency and anemia

Inadequate dietary intake

32

How do you differentiate Vitamin B12 deficiency and folic acid deficiency when both cause megaloblastic anemia’s

Look at folic acid and B12 levels

33

Hemoglobin composition

4 amino acid chains

Each amino acid chain ends in a heme

O2 binds with iron on the heme portion

34

Iron in Hgb remains in the

Ferrous form

35

Oxidized iron

Results in

Ferric form

Irreversible

Hgb cannot release O2 to the cells

36

Each ferrous can combine with how many oxygen molecules?

So each Hgb molecule can combine with how much oxygen?

1 oxygen molecule per ferrous

4 molecules total (8atoms of oxygen)

37

Drugs that cause methemoglobinemia

Prilocaine
Lidocaine
Benzocaine
NTG, Nipride
Phenytoin
Sulfonamides

38

Clues for methemoglobinemia

Low SpO2 with normal PO2

Chocolate, dark-red, brown/blue arterial blood

Brown urine

39

How to diagnose of methemoglobinemia

Direct measurement by co-oximetry (normal 2-3%)

Clinical cyanosis in the presence of normal arterial PaO2

Pulse oximetry- hover around 85%

40

Treatment of asymptomatic methemoglobinemia

Level <20%

Discontinue offending agent

41

Treatment of symptomatic methemoglobinemia

level >20%

Methylene blue 1-2mg/kg IV over 5 minutes

Blood transfusion

Hyperbaric oxygen

42

How methylene blue works

Reverses ferric form of iron back into ferrous form

43

Transport form of iron

Transferrin

44

Storage form of iron

Hemosiderin

45

High hemosiderin S/S and causes

Iron deposits in skin

Caused by massive blood transfusions

46

Breakdown of aged, abnormal, damaged RBC

HGB broken into heme and globin portion

Globin broken down into amino acids and returned to AA pool

Heme portion broken down- iron released. Binds with transferrin goes to storage sites (spleen, liver, bone marrow)

Heme binds with belverdin to become bilirubin (free)

Free bilirubin transferred to liver. Conjugated and excreted

47

Causes of elevated unconjugated bilirubin

Liver failure

Hemolysis of RBC faster than liver can conjugate them

48

Causes of elevated conjugated bilirubin

Obstruction- liver, bile duct, gall bladder

49

Amount of oxygen dissolved in plasma of arterial blood

2-3%

Component measured for ABG PaO2

50

Amount of oxygen combines with ferrous on heme f=portion of Hgb in RBCs

97-98%

51

Arterial side at alveolar capillary interface PO2 and PCO2

PO2 104

PCO2 40

52

Blood in LA PO2 and PCO2

PO2 95

PCO2 40

53

Capillary tissue interface arterial side PO2 and PCO2

Capillary
PO2-95. PCO2-40

Interstitial fluid
PO2- 40. PCO2 45

Tissue
PO2 20. PCO2 46

54

Capillary tissue interface venous end PO2 and PCO2

Capillary
PO2 40. PCO2. 45

Interstitial Fluid
PO2 40. PCO2 45

55

Venous side alveolar-capillary interface PO2. PCO2

Capillary
PO2 40. PCO2 45

Alveolar
PO2 104. PCO2. 40

56

PO2 lower in LA than pulmonary

Bronchial circulation

Thebesian veins

57

Oxyhemoglobin dissociation curve depicts

Relationship between PO2 and saturation of hemoglobin with O2 or affinity of Hgb for O2

58

Normally when Hgb 50% saturated the PO2 should be

27 mmHg

59

For a given PO2 sat is less than expected

Causes

Right shift

Acidosis
Increased CO2
Increased temperature
Increased 2,3 DPG

60

For a given PO2 O2 sat is higher than expected

Causes

Left shift

Alkalosis
Decreased CO2
Decreased temperature
Decreased 2,3 DPG

61

Administration of opioids shifts oxyhemoglobin dissociation curve which direction?

Why?

Right

Hypoventilation = acidosis = increased CO2 = decreased affinity of Hgb for oxygen

62

Normal physiologic shifting of the oxyhemoglobin dissociation curve

How CO2 affects transport of O2

Bohr effect

63

Bohr effect MOA

CO2 diffuses out causing blood to be more alkaline = Shifts 3% left in lungs to pick up more O2

CO2 diffuses into the blood causing acidosis = Shifts 3% right in tissues to favor O2 release

64

Normal physiologic effect

How O2 affects transport of CO2

Haldane effect

65

Haldane effect MOA

In lungs O2 diffuses into lungs displacing CO2- CO2 exhaled

In tissues O2 diffuses into cells freeing up Hgb for CO2 to bind- allows CO2 transport

66

Transport of CO2 phase 1

Tissue-capillary level

5% dissolved in plasma
95% enters RBC

30% binds with Hgb = carbamino hemoglobin
65% reacts with water to form carbonic acid
Carbonic acid dissociates into bicarb
And H+
H+ carried on Hgb (AA in globin)
HCO3 diffuses into plasma and
chloride shifts in

67

Phase 1 of chloride shift

HCO3(out) traded for Cl- (in) to maintain electrical neutrality

Hamburger Shift

Capillary tissue level

68

Phase 2 of CO2 transport

Capillary-alveoli level
-5% diffuses out for -exhale
- 30% displaced by O2 on Hgb and diffuses out for exhalation
- 65% O2 combines with Hgb displacing H+. H+ binds with HCO3 making carbonic acid. As bicarb decreases chloride moves out and bicarb moves in
- CO2 and water diffuse from RBC to be exhaled

69

Phase 2 of chloride shift

HCO3 (in) and chloride (out) at capillary alveolar level

Hamburger shift

70

Average volume of RBCs

MCV (mean corpuscular volume)

Measured in fentoliters

71

Average amount of Hgb in RBC

MCH (mean corpuscular hemoglobin)

Picograms

72

How concentrated the RBC is with HGB

MCHC (mean corpuscular hemoglobin concentration)

%

73

Variability in size of RBC

RDW. (Red cell distribution width)

%

74

Retic- LOW

MCV- HIGH

Plasma Iron- HIGH

Serum ferritin- HIGH

Serum B12- LOW

Bilirubin- SLIGHTLY HIGH

Pernicious anemia

B12 anemia

75

Retic- LOW

MCV- HIGH

Plasma Iron-HIGH

Folate- LOW

Bilirubin- SLIGHTLY HIGH

Folate deficiency anemia

Maturation factor deficit

76

Retic- NORM or SLIGHTLY HIGH/LOW

MCV- LOW

Plasma Iron- LOW

TIBC- HIGH

Serum ferritin- LOW

Iron deficiency anemia

77

Retic- HIGH

Others normal

Post hemorrhagic anemia

78

Retic- HIGH

MCV- NORMAL or HIGH

Plasma Iron- NORMAL or HIGH

Bilirubin- HIGH or SLIGHTLY HIGH

Hemolytic anemia

79

O2 is transported via which portion of Hgb

Iron in the heme portion

80

CO2 is transported on Hgb where

Globin portion

81

MCV >100fl

Descriptor

Cause/significance

Macrocytosis

Megaloblastic/macrocytic anemia

82

MCV <80 fl

Descriptor

Cause/significance

Microcytosis

Iron deficiency anemia
Anemia of chronic disease

83

MCH <26pg
MCHC <27%

Descriptor

Cause/significance

Hypochromia

Decreased cell hemoglobin

84

Variability of RBC shape

Descriptor

Cause/significance

Poikilocytosis

Sickle cell
Leukemia
Hemolysis

85

Variability of RBC size

Descriptor

Cause/significance

Anisocytosis

Reticulocytosis
Abnormal bone marrow production of RBCs

86

MCHC high
Loss of biconcave shape

Descriptor

Cause/significance

Spherocytosis

Hereditary
Increased RBC destruction

87

Cell fragments in circulation

Descriptor

Cause/significance

Shistocytosis

Trauma to RBCs
Hemolysis

88

Irregularly spiculated RBC surface

Descriptor

Cause/significance

Liver disease
Abnormal RBC membrane