Blood

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Blood

• Easily accessable
• Frequently accessed

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Function of Blood as a Tissue

• Transport
• Defense
• 3. Maintenance of Internal Temperature and pH.

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Composition

• 6-8 of Body weight
• 5 liters
• Volume can change (some).

On average - 12 in pulmonary vessels 79 in
systemic vessels 9 in heart
Composed of 45 red cells 2 white
cells 53 plasma
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Viscosity

• Water 1
• Blood 4.5
• Plasma 2.2

Too much viscosity can be harmful to the heart,
BP, blood vessel. (polycythemia can shift crit
???????
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We can see properties of blood as a tissue
reflected in its component parts.

• A.) Plasma

centrifuge allow to clot
Blood ?Plasma (supernatant) ? Serum
(supernatant)
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Plasma is extremely complex

• 1 liter of plasma ? 930 g H2O
• 60g protein
• 8g inorganic ions
• 2g organic compounds

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Also contains gases, hormones, enzymes, vitamins,
and waste products
Anions Cations Bilirubin And other
Pigments Drugs Penicillin, Asprin, Thyroxin
Substances bound To plasma proteins
Heme Iron Vitamins Hormones Cholesterol Glycerides
Fats Lipids Vit. A,D,E,K Thyroxin Cortisol Vit
B12 Bilirubin
Lipids Triglicerides Copper Hemoglobin
?
?2
?2
?1
?1
Globulins
Albumin
Fibrinogen
Ceruloplasmin Erythropoietin Prothrombin Angiotens
inogen Haptoglobin
Transferrin Complement Low-density Liproteins Prof
ibrinolysin
IgG IgA IgM IgE
Transcortin Thyroxide-binding Globulin High-densit
y Lipoproteins Bilirubin-binding
globulin Transcobalamin
Plasma proteins
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B. Cells in Blood

• White cells-function in immunologic defense
  dealt with in immunology course
• Red cells
• Megakaryocytes ? platelets

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Red Cells

• About 5.106 per mm3.
• Biconcave ? increases surface area.
• 200-300 x 106 molecules of Hb per cell.
• Role in transport of gases and pH maintenance.
• 16g of Hb per 100ml of blood
• 1.34 ml of O2 bound per gm of Hb 20 ml of
  O2/100 ml blood.
• 6. Adult Hb is ?2 ?2
• Fetal Hb is ?2 ?2 Absorbs O2 efficiently at low
  pO2.
• 7. t1/2 of typical erythrocyte in human is 125
  days.
• 8. Red cells need steady supply of iron,
  re-utilization is efficient but we still lose
  0.5-4.0g of Ffe per day
• Erythropoiesis occurs in bone marrow of certain
  bones stimulated by Erythropoietin which released
  by kidney in response to low pO2.
• 230 billion red cells destroyed each day.

SPLEEN MACROPHAGE
BLOOD
Amino Acids
Amino Acids
Death
Globin FeII Fe III
Heme Biliverdin Bilirubin
Fe III Transferin
Albumin Liver
albumin
Bilirubin Transport Complex
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Blood Typing
A, B, AB, and O groups
A displays A antigen and possesses anti-B
agglutinin B displays B antigen and possesses
anti-A agglutinin AB displays A and B antigen and
possess no agglutinin O displays neither antigen
and possesses both anti-A and anti- B
agglutinins
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RH Blood Group
Most rhesus antigens are weak, however presence
of the rhesus D antigen elicits a powerful
response.
Rh ? contains the D antigen on the rbc Rh- ?
does not
Antibodies to the Rh factor are not normally
present in Rh- individuals however, Rh-
individuals can generate anti Rh antibodies as
a result of exposure of blood (e.g. during
childbirth).
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C. Origin of ABO Blood Groups

• The A/B antigens are not the primary gene
  products, although they are inherited!

• In the product of an N-acetylgalactosyl
  transferase
• Whereas B is the product of a glactosyl
  transferase

NAc-Gal-?l?3
?
A is
Gal?l-Carb-lipid
?
Fuc- ? 1?2
Gal-? 1?3
?
B is
Gal?l-Carb-lipid
?
Fuc- ? l?2
O is
Fuc- ? l?2 ?Gal?l-Carb-lipid
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Rh Blood Group
Most rhesus antigens are weak, however presence
of the rhesus B antigen elicits a powerful
response.
Rh ?contains the D antigen on the rbc
Rh- ?does not
Antibodies to the Rh factor are not normally
present in the Rh- individuals can generate anti
Rh antibodies as a result of exposure of blood
(e.g. during childbirth).
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A. Immunization Against Rh Blood
O- mothers often do not have children with
erythroblastosis fetalis even with multiple births
How come?
Realization of what was involved, led to the
introduction of rhogam as a treatment to avoid
this disease
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Artificial Blood
Disadvantages of using whole blood for
transfusions are many.

• Expensive.
• Blood typing can restrict use.
• Contamination issues.
• Limited storage lifetime
• Insufficient supply expected to develop soon.
• Not applicable in poor countries
• Artificial blood today is found as
• a. Hb
• b. Perfluorocarbons

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(a) Hb
Advantages

• Can be made from expired human blood.
• Some indications bovine Hb can be used.
• Binds and releases O2 as well as in red cells.
• Can be stored.
• 5. No ABO matching required.

Disadvantages

• Hb cannot be used directly as it breaks down into
  monomers and is excreted rapidly in urine.
• So Hb must be crosslinked chemically to maintain
  body lifetime.
• Tedious process to remove viruses and other
  biological agents.
• Causes oxidation problems.
• Causes hypertension.
• 6. Still expensive.

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b. Perfluorocarbons
E.g. CF3 (CF2)6 CF2 BR Perfluoroocytlbromide
Properties

• This is highly insoluble in water (and plasma).
• This solvent dissolves O2 well at normal
  atmospheric concentrations and releases this gas
  under low O2 tension in tissues.
• Vice versa for CO2.
• 4. A very stable emulsion can be made by mixing
  vigorously with egg yolk lecithin (a
  phospholipid). The emulsion is table over time.

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Advantages

• Relatively inexpensive, made on large scale.
• No contamination with biohazards.
• No ABO matching required.
• Doesnt seem to have adverse effects on human
  physiology.
• Can be stored indefinately, as sterile solution.
• 6. Perfuses tissues very well due to small size
  of emulsion droplets (1/70th of that of r.b.c.).

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Disadvantages

• Exceedingly long body lifetime.
• Still in clinical trials.
• Earlier formulations increased BP by activating
  complement system.
• 4. Still earlier days.but it looks promising.