What is Blood by vmarcelo

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									What is Blood?
      Characteristics of Blood
 Complex mixture of cells, cell fragments,
  and dissolved biochemicals
 Transports nutrients, oxygen, wastes, and
  hormones
 Helps maintain interstitial fluid and
  distributes heat
 Links the body’s internal and external
  environments
 Plays a vital role in homeostasis
              What is it?
 Blood is a type of connective tissue
 Cells are suspended in a liquid
 Major component of the cardiovascular
  system along with the heart and blood
  vessels
          Blood and Blood Cells
   Blood is heavier and
    3 – 4 times more
    viscous than water.
   Most blood cells are
    formed in bone
    marrow
   Blood platelets = cell
    fragments
                Blood Volume
   Factors that affect Blood volume:
    – body size
    – changes in fluid intake
    – electrolyte concentration
    – amount of adipose tissue
   An average adult has about 5.3 liters of
    blood in their body
            Blood Composition
   Blood is usually about 45% cells
    – Most blood cells are red
    – Small number of white cells and platelets
   The remaining 55% is a clear straw-
    colored liquid called plasma
    – Plasma is a mixture of water, amino acids,
      proteins, carbohydrates, lipids, vitamins,
      hormones, electrolytes and cellular waste
              Red Blood Cells
   Erythrocytes = Red
    Blood Cells
   Shape = biconcave
    discs
   Shape allows for
    increased surface
    area through which
    gases can diffuse
         Red Blood Cells Cont.
 Red blood cells contain hemoglobin which
  carries the oxygen in the blood
 Hemoglobin is a protein and is responsible
  for the red color of blood
    – Oxyhemoglobin – oxygen combined with
      hemoglobin = bright red
    – De-oxyhemoglobin – hemoglobin after oxygen
      is released = darker red
         Red Blood Cells Cont.
   Red blood cells have nuclei during early
    stages of development but get rid of them
    as they mature to make room for
    hemoglobin
                   Question
   Describe the limitations of red blood cells
    given that they don’t have a nucleus?
Red Blood Cells
         Red Blood Cell Counts
 Red Blood Cell Count = # of RBCs in a
  cubic millimeter of blood
 Typical range for adult
    – Females = 4,200,000 – 5,400,000 cells per cubic mm
    – Males = 4,600,000 – 6,200,000 cells per cubic mm
       Red Blood Cells Cont.
 The more RBCs the greater the blood’s
  oxygen carrying capacity
 Changes in the number of RBCs may
  affect health
 RBC counts are routinely conducted to
  help diagnose and evaluate disease
     Control of RBC Production
 Formation of RBC = hemopoiesis
 RBC are produced in the red bone marrow
 The average life span of a red blood cell is
  120 days

     What type of mechanism could control
     production of RBC’s?
              RBC Production
   Homeostatic control of RBC production
    – Negative feedback mechanism
    – Controlled by hormone – erythropoietin
    – Hormone produced in the liver and kidneys
      due to prolonged oxygen deficiency.

     What physiological stresses could cause
    prolonged oxygen deficiency?
        RBC Production Cont.
 1. Decrease on blood oxygen
 2. Release of erythropoietin from liver
  and kidneys
 3. Erythropoietin travels via blood to red
  bone marrow
 4. Stimulates RBC production
          RBC Production Cont.
   Takes a few days for new RBC to appear in the
    circulating blood
   Production of new RBC’s continues until the
    number of erythrocytes in circulation is sufficient
    to supply tissues with oxygen requirements.

 Recall the issue of oxygen debt in the muscular
 system. Why might the liver produce the
 hormone to stimulate RBC production?
         Question #1
   Which of the following is a function of
    blood?
       A. Prevents fluid loss
       B. Involved in regulation of body
           temperature
       C. Carries oxygen to cells
       D. All of the above
  Question #2

Erythrocytes
  A. Are the least numerous formed
  element in blood
  B. Are cylindrically shaped cells
  C. Are produced in yellow bone marrow
  D. Do not have a nucleus
             Question #3
Erythropoietin
  A. Is produced mainly by red bone
      marrow
  B. Inhibits the production of erythrocytes
  C. Production increases when blood
      oxygen levels decrease
  D. All of the above
           Question #4
The composition of blood is:
 A. 55% plasma, 45% formed elements
 B. 45% plasma, 55% formed elements
 C. 50% plasma, 50% formed elements
 D. none of the above
             Question #5
Which of the following formed elements
 carry oxygen?
    A. Leukocytes
    B. Erythrocytes
    C. Thrombocytes
    D. Monocytes
              Question #6
The structure of red blood cells is that of
     A. A disk that is convex on one side
          and concave on the other
     B. Irregularly shaped fragments
          without a nucleus
     C. Relative large cells with multiple
          nuclei that stain blue
     D. Biconcave disks that carry
          hemoglobin
              Question #7
Erythropoietin is released by the kidney in
  direct response to
      A. A decrease in the number of red
            blood cells
      B. An increase in circulating biliverdin
      C. Stimuli originating in the lungs
      D. A decrease in circulating oxygen
            concentration
    Dietary Factors Affecting RBC
             Production
   B-complex vitamins (B12 and folic acid)
    significantly influence RBC production
    – These vitamins are essential to DNA synthesis
   Iron
    – Required for hemoglobin synthesis and RBC
      production
    – Iron can be reused by the body after cell
      decomposition or RBC’s
        Too few RBC’s or not enough iron causes anemia
            Sickle Cell Disease
   Read Blue box on pg 309.
    – What causes the disease?
    – How does the disease affect a person’s ability
      to carry oxygen? How?
    – What are the symptoms of the disease?
    – What treatments exist?
    Destruction of Red Blood Cells
   Macrophages phagocytize and destroy
    damaged red blood cells
    – Hemoglobin molecules are broken down into
      subunits
        Heme – iron-containing portion
           – Decomposes into iron and greenish pigment called
             biliverdin
           – Iron can be reused in red bone marrow to make new
             hemoglobin
           – Or it can be stored in the liver where it is converted
             into an orange pigment called bilirubin
           – Both biliverdin and bilirubin are excreted in the liver
             as bile
        Globin – protein
                  Jaundice
   Read Blue Box pg 311
    – What is jaundice?
    – What causes jaundice?
    – How is it treated?
             Question #8
The diagnostic blood test that detects
 anemia is
     A. Type and cross match
     B. Hemoglobin measurement
     C. White blood cell count
     D. Prothrombin time
              Question #9
Sickle Cell anemia is a genetic disease which
  causes hemoglobin in red blood cells to
  crystallize is response to
      A. Low iron content in blood
      B. High oxygen levels in blood
      C. Low oxygen levels in blood
      D. High lipoprotein content
            Question #10
As red blood cells are broken down, the iron
  decomposes into two sub-units of:
     A. Biliverdin and bilirubin
     B. Heme and globin
     C. Iron and biliverdin
     D. Protein and bilirubin
White Blood Cells and
      Platelets
          White Blood Cells
 White Blood Cell = Leukocyte
 Function – protect against disease
 Develop from hemocytoblasts (stem cell)
 Blood transports white blood cells to sites
  of infection
 White blood cells have the ability to leave
  the blood stream
       Types of White Blood Cells
   Granulocytes –       develop in red bone marrow, short
    life span (12 hrs)
    – Neutrophils
    – Eosinophils
    – Basophils
   Agranulocytes –      develop in red bone marrow and
    lymphatic system, long life span (months to years)
    – Monocytes
    – Lymphocytes
       White Blood Cell Function
   Protection against infection
    – Phagocytize bacterial cells
    – Produce proteins (anitbodies) that destroy or
      disable foreign particles
    – Some can leave the circulation
    – Inhibition of blood clotting
        Heparin – prevents intravascular blood clot
         formation
        Histamine – Increases blood fowl to injured tissue
        White Blood Cell Counts
   The number of WBC’s in a cubic millimeter
   A WBCC normally contains 5,000 – 10,000 cells
   Changes in response to abnormal conditions (ex.
    infection)
    – Leukocytosis - acute infection with more than 10,000
      WBC’s per mm3 (ex. appendicitis)
    – Leukophenia – WBCC below 5,000 per mm3 (typhoid
      fever, influenza, measles, mumps, chicken pox, AIDS)
    White Blood Cell Counts Cont.
   Differential white blood cell count
    – % of each type of WBC
    – Neutrophils increase during bacterial infection
    – Eosinophils increase during parasitic infections
      or allergic reactions
    – Lymphocyted decrease sharply in individuals
      with AIDS
              Blood Platelets
 Platelets = Thrombocytes
 Cell fragment
 Help close breaks in damaged blood
  vessels, begin clot formation
 Formed from megakaryocytes: cells in
  the red bone marrow
    – Larger fragments shrink and become platelets
    – Develop from hemocytoblasts (stem cells) in
      response to hormone thrombopoietin
Blood Plasma and
   Hemostasis
                Blood Plasma
   Clear straw-colored
    liquid portion of the
    blood in which cells
    and platelets are
    suspended
   It is composed of
    92% water
   Contains a mixture of
    organic and inorganic
    biochemicals
    Function of Blood Plasma
 Transports nutrients, gases and vitamins
 Helps regulate fluid and electrolyte
  balance and maintains an appropriate pH
            Plasma Proteins
 Most abundant dissolved substance in
  plasma
 Remain in the blood and interstitial fluid
  and are not used as an energy source
    Three Types of Plasma Proteins
   Albumins
    – Account for 60% of plasma proteins
    – Important in regulation of osmotic pressure in the plasma which
      translates to blood volume which is directly related to blood pressure
    – Smallest plasma protein
   Globulins
    –   Accounts for 36% of the plasma proteins
    –   Can be divided into alpha, beta and gamma globulins
    –   Beta globulins transport lipids and fat-soluble vitamins
    –   Gamma globulins are a type of antibody
   Fibrinogen
    – Accounts for 4% of the plasma proteins
    – Functions in blood coagulation
    – Largest of the plasma proteins
             Blood Gases
 The most important blood gases are
  oxygen and carbon dioxide
 Plasma also contains a significant amount
  of nitrogen
            Blood Nutrients
 Include: amino acids, simple sugars,
  nucleotides and lipids
 Plasma lipids include fats (triglycerides),
  phospholipids, and cholesterol
                   Lipoproteins
   Fats combine with proteins in the plasma to
    form lipoprotein complexes
   Lipoproteins are classified on the basis of their
    density which reflects their concentration of fat
    – VLDL (Very low-density lipoproteins) have a high
      concentration of triglycerides
    – LDL (Low-density lipoproteins) have a relatively high
      concentration of cholesterol and are the major
      cholesterol-carrying lipoproteins
    – HDL (High-density lipoproteins) have a high
      concentration of protein and a lower concentration of
      lipids
    Other Components of Plasma
   Nonprotein Nitrogenous Substances –
    molecules that contain nitrogen atoms but
    are not proteins
    – Includes amino acids, urea, and uric acid
   Plasma Electrolytes – absorbed from the
    intestine or released as by-products of
    metabolism
    – Includes sodium chloride ions and bicarbonate
      ions
                  Hemostasis
 The stoppage of bleeding to damaged
  blood vessels
 Includes the following processes:
    – Blood vessel spasm
    – platelet plug formation
    – Blood coagulation
            Blood Vessel Spasm
   Cutting or breaking of
    blood vessels stimulates
    the smooth muscles in its
    walls to contract, and
    blood loss lessens almost
    immediately –
   Allows time for platelet
    plug to form
   Platelets release
    serotonin which contracts
    walls of blood vessel
    walls helping to reduce
    further blood loss
          Platelet Plug Formation
   Platelets stick to any
    rough surface
   When a blood vessel
    breaks, platelets adhere
    to the collagen lining of
    the blood vessels
   Platelets also stick to
    each other forming a
    platelet plug
   Platelet plugs control
    blood loss only from small
    breaks. Larger breaks
    require a blood clot
                  Blood Coagulation
   Causes the formation of a blood clot
   Blood coagulation is complex and utilizes many biochemicals called
    clotting factors
     – Some factors promote coagulation and others inhibit it
          Whether or not blood coagulates depends on the balance between the two
           groups
   Abnormal clot formations
     – Antherosclerosis – accumulation of fatty deposits that change the
       arterial linings
     – Coronary thrombosis – blood clot forming in the vessels that supply the
       heart
     – Cerbral thrombosis – blood clot forming in the vessels that supply the
       brain
     – Infarction – when tissue is killed due to clot
     – Empolism – that travels and then blocks a vessel that supplies a vital
       organ (pulmonary embolism)
Blood Clot Formtation
            Question #11
Which of the following is not a component
 of plasma?
    A. Albumin
    B. Globulin
    C. Fibrinogen
    D. Platelets
               Question #12
Platelet   plug begins to form when platelets
  are
     A.    Exposed to air
     B.    Exposed to a rough surface
     C.    Exposed to calcium
     D.    Crushed
             Question #13
Lipoproteins are categorized by their
     A. Size
     B. Density
     C. Solubility
     D. Shape
Blood Groups and
   Transfusions
        Antigens and Antibodies
   Agglutination – clumping of red blood cells
    following a transfusion reaction
    – Due to reaction between red blood cell
      surface molecules (antigens) and protein
      (antibodies) carried in plasma
   Mismatched blood transfusion quickly
    produces signs of agglutination
    – Anxiety, difficulty breathing, facial flushing,
      jaundice and ultimately kidney failure
                ABO Blood Group
   The ABO blood group is based on the presence
    (or absence) of two major antigens on red blood
    cell membranes
    – Antigen A
    – Antigen B
   A person has one of four antigen combinations
    on their erythrocytes
    –   Only A – A Blood Type
    –   Only B – B Blood Type
    –   Both A and B – AB Blood Type
    –   Neither A nor B – O Blood Type
ABO Blood Types
                Antibodies
   Antibodies are synthesized in the plasma
    – When antigen A is absent, anti-A (antibody) is
      produced
        Persons with type B blood have anti-A in their plasma
    – When antigen B is absent, anti-B is produced
        Persons with type A blood have antibody anti-B in their
         plasma
    – When both antigen A and B are present, neither
      antibody is produced
    – When neither antigen is present, both antibodies
      are produced
                  Blood Types
   In the U.S.
    – Type O (47%) and Type A (41%) are the most
      common, Type B (9%) and AB (3%) are rarer


           Blood Type Antigen           Antibody
           A          A                 Anti-B
           B          B                 Anti-A
           AB         A and B           Neither anti-A nor anti-B
           O          Neither A nor B   Both anti-A and anti-B
                Blood Types Cont.
   A person with type A blood cannot receive blood type B or AB,
    either would clump in the presence of anti-B
   A person with type O blood must not receive type A, B or AB blood
   Persons with AB blood can receive any type of blood (Universal
    recipient)
     – Type A blood, type B blood and type O blood still contain
        antibodies that could agglutinate type AB cells if transfused
        rapidly. For this reason, AB recipients usually receive AB blood
   Persons with O blood can donate to any other blood type (Universal
    donor)
     – Same issues as with type AB blood, must be transfused slowly.
              Rh Blood groups
   Rh blood group was named after the rhesus
    monkey in which it was first studied.
   This group includes several Rh antigens (factors)
   If any of the factors are present on the RBC
    membrane, the blood is said to be Rh positive.
   If the RBC lacks Rh antigens, the blood is Rh
    negative
             Question #14
Type AB blood
     A. Has type A antigens
  B. Has type B antibodies
     C. Will not cause a transfusion
          reaction if given to a person with
          type O blood
     D. All of the above
            Question #15
A person with antibody A in his or her
  plasma would have which blood type?
     A. Type A
     B. Type B
     C. Type AB
     D. Type O
             Question #16
People with type O blood are considered to
  be universal donors because their blood
  contains:
     A. Neither A or B antigens on their
        RBCs
     B. Both A and B antigens in their blood
        plasma
     C. The Rh antigen on their RBCs
     D. None of the above
            Question #17
The only people who can ever have anit-Rh
 antibodies in their plasma are:
     A. Rh-negative men who have been
        transfused with Rh positive blood
     B. Rh-negative women who have been
         transfused with Rh positive blood
     C. Rh-negative women who have
         carried an Rh-positive fetus
     D. All of the above

								
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