the Blood final by m3pZe5x

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									The BLOOD
Introduction
   Circulatory systems:
       Open
           Hemolyph
           Arthropods, molluscs
       Closed
           Blood separate from interstitial fluid
           Earthworm, squid, octopus, vertebrates
Blood
   Type of connective tissue
       Liquid/fluid
           Solid cells suspended in fluid plasma
               Red blood cells (RBCs; erythrocytes)
               White blood cells (WBCs; leucocytes)
               Platelets (thrombocytes)
           Plasma
               Water
               Dissolved substances: proteins, food,
                excretory products
Red Blood Cells
   Mammalian
       round biconcave discs without a nucleus
       diameter: 7 μm
       thickness: 2 μm
       life span: 100-120 days in circulation
   Other vertebrates
       have a nucleus
       oval-shaped
       frequently much larger than mammalian cells
Red Blood Cells
   Hematocrit
       volume percentage of red blood cells in the
        total blood volume
           Males: 47%; females: 42%
           Infants: 50-70%; adults: 45%
Red Blood Cells (RBCs)
Hematocrit
   Polycythemia
       increase of hematocrit
           Absolute – actual increase in RBC number
           Apparent – no increase in RBC number, only in
            concentration
   Oligocythemia
       decrease of hematocrit
           Absolute – actual decrease in RBC number
           Apparent – no decrease in RBC number, only in
            concentration
Hematocrit
   Physiological reasons for change
       Change in altitude
       After strenuous activities
       --mainly due to response to physiological
        conditions


   Pathological reasons for change
       Abnormal changes due to impairment of
        production, not physiological need
            White Blood Cells
   white in color
   have a nucleus
   life span: only 2-3 weeks in circulation


                    Platelets
   size: about only one-fourth of RBCs
   no nucleus
   consist only of lumps of cytoplasm
Functions of Blood
   Transport
       Nutrients and metabolites
       Excretory products
       Gases
       Hormones
       Heat
-- diffusion is impractical over long distances
Functions of Blood
   Transmission of force
       Movement of organs
   Coagulation
       Prevents blood loss
    •   Provides suitable medium for cells and
        helps in regulation of pH and temperature
        in body fluids
    •   -- Maintenance of internal environment
        (Homeostasis)
       Medium of contact between cellular and external
        environments
Methods
  ABO Blood Typing


  A        B




                     A   B
 A             B
Clotting Time




 Recorded time until      Used a pin to draw
 fibrin thread clung to   blood from center to
 pin                      periphery
Factors affecting Coagulation

    Chicken was               Blood added to   empty
        bled                  test tubes:
                                               With paraffin

                                               Cotton fibers
                     Record time
                      of clotting              In ice bath

                                               In hot water bath
                                               Continuously stirred
                                               1% sodium
                             +5                oxalate
 Beat until fibrin
                            drops              1% sodium citrate
forms; observed
    under the              sodium
                           chloride            0.1% heparin
   microscope
Blood Pigment

        1.5 mL citrated                    Color change
        blood poured in 2                  observed
        test tubes each




Color change                Color change   Color change
observed                    observed       observed
Blood Cell Count
Hemocytometer
   Originally used in counting
    RBCs
   Consists of a thick glass
    microscope slide with a
    rectangular indentation
    that creates a counting
    chamber
   Counting chamber -
    engraved with a laser-
    etched grid of
    perpendicular lines
   Raised edges hold cover
    slip above these marked
    grids
    Hemocytometer
   Counting chamber is a 3 x 3
    mm square and divided into
    nine large squares
   Each resulting square
    measures 1 mm2, which are
    used for white blood cell
    counting (Square A)
   The center square is divided
    into 25 smaller squares. (1/25
    mm2)
   Each smaller square is
    subdivided into 16 even
    smaller squares, which are
    used for counting red blood
    cells. (Square B = 1/400 mm2)
Determination of Number of Cells per mL

    Coverslip sits 0.1 mm over the chamber
    1mm 3 = 10-3 cubic centimeters (cc) or ml
    Volume of a square = 1 mm x 1 mm x 0.1 mm = 0.1 mm3 =
     10-4 cc = 10-4 mL
    Take the average of the cells found in the 5 squares (the four
     corners and the middle one).
    Avoid counting the cells twice by disregarding the cells found
     at the upper and left borders
    Multiply this by 104 to get the # cells/ml in the suspension.
    If, however, the suspension was diluted prior to counting,
     then one would also multiply by the dilution factor to get the #
     cells/ml in the culture flask.
 Avg. # cells counted x 104 = # cells/ml (x DF if any)
Agglutination and
Blood Typing
Agglutination

   The clumping of cells such as red blood cells in
    the presence of an antibody.
   The antibody binds multiple particles and joins
    them, creating a large complex.
   Hemagglutination - specific form of agglutination
    that involves red blood cells (RBC’s) and can be
    used to identify RBC surface antigens with
    known antibodies.
   Uses anti-A and anti-B antibodies that bind
    specifically to either the A or to the B blood group
    surface antigens on RBCs.
   Result: A = 6, B = 6, AB = 1, O = 3
ABO System of Blood Typing
Rh System of Blood Typing
   Erythroblastosis fetalis: mother – fetus
    incompatibility
   Occurs when mother is Rh- and father is Rh+
   Maternal antibodies can cross the placenta and
    destroy fetal red blood cells.
   The risk increases with each pregnancy.
   The standard treatment is immediate massive
    transfusions of Rh+ blood into the baby with the
    simultaneous draining of the existing blood to
    flush out Rh+ antibodies.
   Rho-GAM serum – agglutinates fetal RBCs as
    they enter the mother’s blood
Blood Clotting
    Clotting Time
   Thrombus or blood clot –
    product of blood coagulation for
    hemostasis
   Appear as a plug of platelets
    enmeshed in a network of
    insoluble fibrin molecules.
   Thrombin – regulates platelet
    aggregation and fibrin formation
   Clotting time – measured by the
    length of time from the moment
    the blood is shed to the
    appearance of fibrin
   Presence of fibrin indicates
    macroscopically that clotting is
    in progress.
   Clotting time = 2 mins 36 secs
Blood Coagulation
Coagulation

   Clotting
   Homeostatic function preventing blood loss
   Fibrin mesh formation
   Catalyzed by thrombin



                   Fibrin
Agglutination vs Coagulation

   Agglutination
       Clumping of red blood cells
       Antigen-antibody interaction
   Coagulation
       Clotting of red blood cells
       3 steps involved
Steps in Coagulation

   1st Step
       Formation of prothrombin activator
   2nd Step
       Conversion of plasma protein prothrombin into
        thrombin by the activator
   3rd Step
       Joining of fibrinogen in the plasma
       Formation of Fibrin mesh
Factors Affecting Coagulation

   Normal
   Paraffin
   Cotton Fibers
   Temperature (Hot & Cold)
   Heparin
   Sodium Oxalate
   Sodium Citrate
   Stirring
Paraffin

   Shows decreased
    coagulation rate
   Paraffin lining
    mimics the natural
    configuration of
    blood vessels
Stirring

   Continuous stirring showed
    retarded coagulation since it
    prevents clumping of
    molecules involved in clotting
   Contact between important
    blood components for
    clotting is minimized
Cotton Fibers

   Coagulation observed
   The cotton fibers
    imitate fibrin meshes
    thus faster coagulation
    occurred
Temperature

   Cold Temperature
       Slower clotting time


   Hot Temperature
       Faster clotting time
Heparin
   Naturally-occurring inhibitor
   Prevents coagulation by
    inhibiting conversion of
    prothrombin to thrombin
   Inactivates the blood clotting
    substances thrombin and
    thromboplastin
   0.1% Heparin added to blood
   No blood clotting was
    observed
Sodium Oxalate

   Sodium Oxalate is an
    anticoagulant which
    prevents coagulation by
    precipitating or chelating
    calcium
   Calcium is known to be a
    coagulation promoter
   Sodium Oxalate forms
    complexes and deactivates
    clotting factors
Sodium Citrate

   Sodium citrate prevents
    coagulation by binding
    with Calcium
   Since free calcium ions in
    the solution is decrease
    due to binding with
    sodium citrate,
    coagulation is inhibited
Addition of Calcium Chloride

   Calcium ions were provided by calcium chloride
    when it dissociates
   Addition of calcium chloride to the blood-heparin,
    blood-sodium oxalate and blood-sodium citrate
    mixtures promotes blood clotting
   However, the calcium chelators, Sodium Oxalate
    and Sodium Citrate should have a longer
    coagulation time compared to heparin only
Blood Pigments
Functions of Blood Pigments

   Increases the carrying capacity for oxygen by
    the blood
   Oxygen and carbon dioxide transport
   Buffering systems

     complexes of proteins and metal ions,
    giving a characteristic color that changes
                 upon O2 binding
Hemoglobin
   consists of four globin
    protein subunits, each
    containing four iron-
    containing porphyrin
    prosthetic groups, called
    heme
   Hemoglobin is bright red
    when it is loaded with O2
    and a dark maroon-red
    when deoxygenated
Hemoglobin

   Deoxyhemoglobin
   Oxyhemoglobin
Hemoglobin Structure
Other Respiratory Pigments




Hemerythrin is used by worms, cephalopods,
crustaceans, and spiders - sipunculid worms - four phyla of
marine invertebrates
Other Respiratory Pigments




Chlococruorin, the extracellular hemoglobin of a
polychaete annelid (Sabella Spallanzanii)
Other Respiratory Pigments




 Hemocyanin is found in the hemolymph of many
 invertebrates
Buffer Action in Plasma
Buffer System

   one of the mechanisms by which the body
    diminishes pH changes in body fluid
   ability to oppose charges in pH when small
    amounts of acid or base are added to the
    solution
Buffer Systems

   bicarbonate system
   proteins (mainly hemoglobin)
   the phosphate system
Bicarbonate System

   reaction of HCO3- and H+ ions, forming CO2
   excretion of CO2 is limited by the rate of
    bicarbonate-chloride exchange across the
    erythrocyte membrane
Proteins: Hemoglobin

   has several buffering groups per
    molecule having different pKa values
    (6.5-7.8)
   The numerous imidazole groups, with
    pKa values of approximately 7, are
    responsible for much of the buffering
    carried out by hemoglobin in the blood
   Oxygenated haemoglobin (H:Hb02) is a
    stronger acid than deoxygenated
    haemoglobin (H:Hb)
Phosphate Buffer System

   of two elements: H2PO4- and HPO42-
   pKa of the phosphate system is 6.8
   buffering capacity of this system in the ECF is
    far less than that of the bicarbonate system
   pH is lower in the ICF than in ECF
gia ralph everly mario

								
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