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Physiology 209 > Blood > Flashcards

Flashcards in Blood Deck (109):
1

Blood functions

1. Transport
-Nutritive
-Respiratory
-Excretory
-Hormone transport
-Temperature regulation

2. Acid-Base Balance
-normal pH range 7.30-7.45

3. Protective

2

Accounts for what percent of body mass?

Account for 7% of body mass
~5 L

3

Normovolemia

normal blood volume

4

Hypovolemia

Lower blood volume

5

Hypervolemia

Higher blood volume

6

Total Blood Volume occupied by blood and Plasma

blood ~2.25 L
plasma ~2.75L

7

Composition of Plasma

1. >90% water
2. Na+, K+ , (Ca++, Mg++)
Cl-. HCO3-, (PO4--)
3. Glucose, amino acids, lipids, O2, CO2
4. Proteins (colloids) = 7%g
Albumins
Globulins
Fibrinogen

8

Separating Plasma Proteins

1. Differential Precipitation by Salts
2. Sedimentation in Ultracentrifuge
3. Electrophoretic Mobility
4. Immunological Characteristics

9

Electrophoresis

-fractionation method based on movement of charged particles along a voltage gradient
-rate of migration is influenced by the number and distribution of charges and by MW of each protein.

10

Origin of Plasma Proteins

Liver: Albumin, Fibrinogen, alpha1 and 2, Beta globulins

Lymphoid Tissue produces Y globulin

11

Plasma Proteins Properties

Albumin, 69 MW, 4g% conc.
Globulin, 90-800 MW, 2.7g%
Fibrinogen 350 MW, 0.3g%

12

Role of Plasma Proteins

1. Major role in determining the distribution of fluid between the plasma and the ISF compartments by controlling transcapillary dynamics.

13

What does Plasma have more of than ISF, in regards to make up?

Plasma and ICF both have somewhat equal conc. of Na, K, Cl, HCO3.

Plasma has more protein than ISF!

14

Colloidal Osmotic (Oncotic) pressure (C.O.P.) of plasma

Only non-diffusable solutes contribute to the effective Osmotic Pressure of a solution

Diffusible solutes do not contribute

Plasma Proteins are non-diffusible , therefore, they can exert an osmotic effect.

15

Osmotic flow

tends to "pull in" or retain fluid inside the capillaries.

16

Starling Forces

1. Filtration
2. Osmotic Flow

17

How much fluid filtered out is reabsorbed directly back into capillaries?

90% reabsorbed
10% is drained by lymphatic vessels

18

Lymphatic System

-A network of blind-ended terminal Tubules, which coalesce to form larger lymphatic vessels, which converge to form large lymphatic ducts,
which drain into the large veins in the chest

19

Lymphatic Vessels

-the walls of lymphatic vessels are made up of a single layer of endothelial cells

-they are highly permeable to all ISF constituents, including proteins(which might have leaked out into the ISF from the plasma)

20

Daily Volume of fluid filtered in ISF by the Capillaries

20L

21

Daily Total blood flow

6,000 L

22

Daily Volume of fluid returned to the capillaries by absorption

17 L

23

Daily volume of fluid returned by lymph drainage into the capillaries

3 L

24

Each protein fraction exerts an osmotic pressure which is

i. directly related to its conc. in the plasma
ii. inversely related to the molecular Weight of that protein

25

COP of Plasma Proteins

Albumin ~20 mmHg
Globulins ~5 mmHg
Fibrinogen ~

26

Factors in Transcapillary Dynamics

1. Hydrostatic Pressure
2. C.O.P.
3. Capillary Permeability
4. Lymphatic Drainage

27

Edema

accumulation of excess fluid in the interstitial spaces.

28

Under which conditions can edema develop?

1. Increased hyrdostatic pressure.
2. Decreased C.O.P.

3. Increased capillary Permeability

Increased filtration
Decrease in Net absorption

29

Causes for Decreased C.O.P.

a. Failure to synthesize plasma proteins
b. Severe protein malnutrition

30

Elephantiasis

blockage of lymphatic drainage resulting from parasite infestation

31

Role of Plasma Proteins

1. Major role in determining the distribution of fluid between the plasma and the ISF compartments by controlling transcapillary dynamics
2. Contribute to the viscosity of plasma
(Viscosity is a contributing factor to the maintenance of BP)
3. Contribute to the buffering power of plasma
-normal pH range ~7.4

32

Specific Plasma Protein Functions

i. Fibrinogen and some globulins are essential to clotting
ii. Y-globulins (immunoglobulins) provide specific resistance to infection
iii. Albumin and some globulins act as carriers for lipids, minerals, hormones

33

Blood Cells

-Red Blood Cells - Erythrocytes
-Platelets - thromocytes
- WBC - Leukocytes

34

Hematopoiesis

-all blood cells are derived from a common multipotential (pluripotential) hematopoietic stem cell
- an inducer will stimulate a Stem cell to progress into a certain type of stem cells

Two phases:
1. Division
2. Differentiation

35

Eythropoiesis

production of RBC

36

Thrombopoiesis

production of platelets

37

Leukopoiesis

production of WBC

38

Cytokines

-substances (protein or peptides) which are released by one cell and affect the growth, development, and activity of another cell

39

Hematopoietic Growth Factors (HGFs)

-cytokines influencing the proliferation and differentiation of blood cell precursors

40

Sites of Hematopoiesis Prenatal

Yolk Sac, Liver and Spleen

41

Sites of Hematopoiesis Postnatal

-Distal long bones, Axial Skeleton
-Flat bones of skull, shoulder blades, pelvis, vertebrae, sternum, ribs, proxymal epiphyses of long bones.

42

Advantage of Shape of RBC (DISK)

1. Maximal surface area and minimal diffusion distance for its volume (Increases the efficiency of O2 and CO2 diffusion)
2. High degree of flexibility (Allows cells to squeeze through narrow capillaries)

43

What is there none of in a red blood cells

No subcellular organelles

44

RBC's important Enzyme Systems

Glycolytic Enzymes --> Generate Energy

Carbonic Anhydrase --> CO2 Transport

45

Carrying Capacity of blood

20 ml O2/ 100 mL blood.

Solubility of O2 in plasma is very low: 0.3 mL O2/100 mL plasma

46

Hb Functions

1. Transport of O2
2. Transport of CO2
3. Acts as a buffer

47

What are the advantages of having Hb inside the Cell (rather than dissolved in plasma)

i. re Plasma Viscosity
ii. re Plasma C.O.P.
iii. re Loss via kidney

48

Hemoglobin Values for Males and Females

female - 16g/100 mL blood
male - 14 g/100 mL blood

49

How much of each gram of Hb holds when it is fully saturated

1.34 mL O2

50

The O2 carrying capacity of blood

15x1.34 = 20 mL O2/100 mL blood

51

Factors affecting the ability of Hb to bind and release O2

1. Temp
2. Ionic Composition
3. pH
4. pCO2
5. Intracellular enzyme conc.

52

Time period for Division and Differentiation of the RBC

3-5 days,
In circulation 24 hours

53

Red Cell precursors Proliferation

1. Decrease in size
2. Lose of nucleus
3. Accumulation of Hb

54

Factors Determining # of RBCs

1. O2 requirements
2. O2 availability

55

How does altitude affect pO2

pO2 decreases with increase of altitude

56

Erythropoietin

-a glycoprotein hormone/cytokine produced largely by the kidney

-if it has been purified, sequenced, gene has been cloned, and EPO has been produced by recombinant DNA technology.

57

What is the stimulus for the release of erythropoietin?

Hypoxia: which may result from decreased RBC count, or decreased availability of O2 to blood, or increased tissue demand for O2.

58

Regulation of Erythropoiesis

Increase in O2 supply --> decreased release of erythropoietin --> erythropoietin in plasma --> bone marrow --> increase in RBCs --> increase in oxygen supply --> back to top

59

Regulation of Erythropoiesis

Erythropoietin, released from the kidney in presence of hypoxia, stimulates the bone marrow to produce more RBC's, thereby maintaining homeostasis

Once there is an increase in O2 supply there is a decreased release of erythropoietin

60

Negative Feedback Loop of Erythropoiesis

Severe accidental hemorrhage --> Less Hb available for O2 transport --> reduced supply of O2 to kidneys --> increased production and release of erythropoietin --> increased production of erythrocyte precursors in bone marrow --> increase discharge of young erythrocytes in blood --> more Hb for O2 transport --> negative feedback to stop production and release of erythropoietin.

61

Erythropoietin Action

Pluripotent Stem Cell --> Commited Stem Cell (EPO Stimulates Proliferation) --> EPO accelerates Maturation --> Reticulocytes --> Mature RBC

62

How does testosterone affect erythropoietin

-increase of erythropoietin
- increase in sensitivity of RBC precursors to Erythropoietin

63

How does estrogen affect erythropoietin

Has opposite effects of testosterone

64

Life span of RBC's

120 days

65

Does anything prolong RBC lifespan

NOTHING!!!!

66

How are RBC's removed

Old RBCs are recognized as such and are removed from the circulation by a system of highly phagocytic cells know as macrophages (in liver and spleen)

67

Jaundice

a medical condition with yellowing of the skin or whites of the eyes, arising from excess of the pigment bilirubin and typically caused by obstruction of the bile duct, by liver disease, or by excessive breakdown of red blood cells.

-excessive hemolysis
-bile duct obstruction causing bilirubin to circulate the body

68

Hemolysis

the rupture or destruction of red blood cells

69

Polycythemia

RBC production > destruction

70

Anemia

RBC production

71

Normal RBC g%

16 g%

72

Polycythemia RBC g%

> 18g% Hb

73

What causes physiological Polycythemia? (secondary of increase in O2 needs or decrease in O2 availability)

-at high altitudes
-increased physical activity
-chronic lung disease
-heavy smoking
-tumors of cells producing erythropoietin
-Unregulated production by bone Marrow

74

What is the problem in polycythemia?

-Increase in blood viscosity
= sluggish blood flow --> blood clots

75

Classification of Anemias

Morphologic:
1. Microcytic Normocytic Macrocytic

2. Normochromic Hypochromic

76

Normocytic

Normal RBC, normal size, shape HB, etc. Just abnormal amount in the plasma

77

Macrocytic

Abnormally large RBC

78

Microcytic

Abnormally small RBC

79

Normochromic

form of anemia in which the concentration of hemoglobin in the red blood cells is within the standard range. However, there are insufficient numbers of red blood cells

80

Hypochromic

red blood cells (erythrocytes) are paler than normal

81

Total Amount of Iron in Body and proportions in the body

4 g in total
65% Hb
30% stored
5% myoglobin
1% enzyme

82

Daily intake in Diet of Iron

~15-20 mg

83

Daily absorption from gut (depending on need by body)

~1 mg Males
~2 mg Females

84

How much Iron that normal erythropoiesis requires

25 mg Fe/d

85

Iron in normal RBC destruction

25 mg Fe/d

1mg/d lost, 24 mg/d recycled

86

What causes Pernicious Anemia?

Intrinsic factor deficiency, which affects Vitamin B12 absorption.
Occurs in the ileum.

87

Loss of Blood - Hemorrhage

a. External
b. Internal (into tissues)

88

Hematoma

accumulation of blood in tisses

89

Hemostasis

the arrest of bleeding following vascular injury

Vascular injury --> Vasoconstriction --> Platelet Plug Formation --> Blood clot formation

90

Primary Hemostasis

Comprised of:
-Vascular response
-Platelet Response

Begins within seconds of injury, lasts only minutes

91

Secondary Hemostasis

clot formation

92

Vascular Response to Injury

-Opposed endothelial cells stick together
-smooth muscle cells in vessel wall respond to injury by contracting

93

Platelet Response (white thrombus)

platelet plug forms

94

Platelet Structure

~2-4 um diameter
-No nucleus
-Many granules: factors for vasoconstriction, platelet aggregation, clotting, growth, etc. many filaments, microtubules, mitochondria, sER.
~ 250,000/uL
Life Span: 7-10d

95

Thrombopoietin

hormone produced by the liver and kidney which regulates the production of platelets.It stimulates the production and differentiation of megakaryocytes, the bone marrow cells that bud off large numbers of platelets.

96

Platelet Plug Formation

1. Adhesion
2. Activation and release of cytokines
3. Aggregation
4. Consolidation

97

Platelet Functions

a. Release vasoconstricting agents/ cytokines
b. Form platelet Plug (Red Thrombus)
c. Release clotting factors
d. Participate in Clot retraction
e. Promote maintenance of Endothelial Integrity

98

Abnormal Primary Hemostatic Response --> Prolonged Bleeding

1. Failure of Blood vessel to constrict
2. Platelet deficiencies
a. Numerical
b. Functional

99

How does aspirin affect TXA2

In small doses inhibits synthesis and release

100

Thrombus

blood clot

101

Clotting

-initiated by injury to blood vessel wall
-results in sequential activation and interaction of a group of plasma proteins/clotting factors (some acting as enzymes, others as cofactors) in the presence of Ca++ and some phospholipid agents

102

The effect of small amounts of thrombin?

The small amounts of thrombin generated rapidly by the extrinsic scheme are sufficient to trigger its strongly positive feedback effects on the intrinsic scheme to generate larger quantities of thrombin

103

Petechaie

a small red or purple spot caused by bleeding into the skin

104

What keeps clotting in check

Inhibitors of platelet adhesion and anticoagulants (naturally occurring chemicals which block one or more of the reactions of coagulation scheme.

105

Clotting Factor Deficiencies

Congenital: hereditary deficiencies (usually) of a single factor . e.g. VII (hemophilia)

Acquired: Usually multifactor deficiencies e.g.
i. Liver disease
ii. Vitamin K deficiency

*Vitamin K is a cofactor in synthesis of Prothrombin, VII, IX, X

106

Thrombosthenin

-contractile protein released by platelets.
-the presence of this determines the retraction of blood.

107

Clot Lysis (Fibrinolysis)

-break down of clots
helped via
1. Inhibitor of Platelet Adhesion(eg. Aspirin)
2. Anticoagulant Drugs (interfere with clot formation)
i. Coumarin
ii. Heparin
3. Thrombolytic Drugs (promote lysis)
i. Tissue Plasminogen Activator (t-PA)
ii. Streptokinase

108

Coumarin

blocks synthesis of functional Prothrombin, VII, IX, X

109

Heparin

Promotes inhibition of thrombin activation and action