Anaphy

Cards (104)

  • Functions of blood
    • Transport of gasses, nutrients and waste products
    • Transport of processed molecules
    • Transport of regulatory molecules
    • Regulation of pH and osmosis
    • Maintenance of body temperature
    • Protection against foreign substances
    • Clot formation
  • Composition of blood
    • Plasma
    • Formed elements
  • Plasma
    55% of total blood, pale yellow liquid that surrounds cells, 91% water, 7% proteins, and 2% other
  • Formed elements

    45% of total blood, cells and cell fragments, erythrocytes, leukocytes, thrombocytes
  • Plasma proteins
    • Albumin
    • Globulins
    • Fibrinogen
  • Albumin
    58% of plasma proteins, helps maintain water balance
  • Globulins
    38% of plasma proteins, helps immune system
  • Fibrinogen
    4% of plasma proteins, aids in clot formation
  • Hematopoiesis
    1. Occurs in fetal liver, thymus, spleen, lymph nodes, and red bone marrow
    2. After birth, primarily in red bone marrow, some white blood cells produced in lymphatic tissues
    3. Stem cells differentiate to give rise to different cell lines, each ending with a particular type of formed element
  • Erythrocytes (Red Blood Cells)
    • Disk-shaped with thick edges
    • Nucleus is lost during development
    • Live for 120 days
  • Erythrocyte function
    Transport O2 to tissues
  • Hemoglobin
    Main component of erythrocytes, transports O2, each globin protein attached to a heme molecule containing one iron atom, O2 binds to iron, oxyhemoglobin is hemoglobin with O2 attached
  • Production of erythrocytes
    1. Decreased blood O2 levels cause kidneys to increase production of erythropoietin
    2. Erythropoietin stimulates red bone marrow to produce more erythrocytes
    3. Increased erythrocytes cause an increase in blood O2 levels
  • Fate of old erythrocytes and hemoglobin
    1. Old red blood cells removed from blood by macrophages in spleen and liver
    2. Hemoglobin is broken down, globin broken down into amino acids, iron recycled, heme converted to bilirubin, bilirubin taken up by liver and released into small intestine as part of bile
  • Leukocytes (White Blood Cells)

    • Lack hemoglobin
    • Larger than erythrocytes
    • Contain a nucleus
  • Leukocyte functions
    • Fight infections
    • Remove dead cells and debris by phagocytosis
  • Types of leukocytes
    • Granulocytes (neutrophils, eosinophils, basophils)
    • Agranulocytes (monocytes, lymphocytes)
  • Neutrophils
    Most common, remain in blood for 10 to 12 hours then move to tissues, phagocytes
  • Eosinophils
    Reduce inflammation, destroy parasites
  • Basophils
    Least common, release histamine and heparin
  • Monocytes
    Largest sized white blood cells, produce macrophages
  • Lymphocytes
    Immune response, several different types (T cells and B cells), lead to production of antibodies
  • Platelets
    Minute fragments of cells, each consisting of a small amount of cytoplasm surrounded by a cell membrane, produced in red bone marrow from megakaryocytes, play an important role in preventing blood loss
  • Preventing blood loss
    1. Vascular spasm (temporary constriction of blood vessel)
    2. Platelet plug formation (can seal up small breaks in blood vessels)
    3. Blood clotting (blood can be transformed from a liquid to a gel)
  • Steps in clot formation

    1. Injury to a blood vessel causes inactive clotting factors to become activated
    2. Prothrombinase (clotting factor) is formed and acts upon prothrombin
    3. Prothrombin is switched to its active form thrombin
    4. Thrombin activates fibrinogen into its active form fibrin
    5. Fibrin forms a network that traps blood (clots)
  • Clot formation control
    Anticoagulants (prevent clots from forming, e.g. heparin and antithrombin)
  • Clot retraction and fibrinolysis
    1. Clot retraction (condensing of clot, serum in plasma is squeezed out of clot, helps enhance healing)
    2. Fibrinolysis (process of dissolving clot, plasminogen breaks down fibrin)
  • Blood grouping
    • Antigens
    • Antibodies
    • Blood groups
  • ABO blood groups
    • Type A has A antigens, type B has B antigens, type AB has both A and B antigens, type O has neither A nor B antigens
    • Plasma from type A blood contains anti-B antibodies, plasma from type B blood contains anti-A antibodies, type AB blood plasma has neither type of antibody, type O blood plasma has both anti-A and anti-B antibodies
  • In Caucasians in the United States, the distribution is type O, 47%; type A, 41%; type B, 9%; and type AB, 3%. Among African-Americans, the distribution is type O, 46%; type A, 27%; type B, 20%; and type AB, 7%.
  • Rh blood group
    Rh positive means you have Rh antigens, 95 to 85% of the population is Rh+, antibodies only develop if an Rh- person is exposed to Rh+ blood
  • Rh incompatibility in pregnancy
    1. If the mother is Rh- and the fetus is Rh+, the mother can be exposed to Rh+ blood if fetal blood leaks through the placenta and mixes with the mother's blood
    2. First time this occurs, mother's blood produces antibodies against antigens
    3. Any repeated mixing of blood causes a reaction
  • Hemolytic disease of newborn
    Occurs when mother produces anti-Rh antibodies that cross placenta and agglutination and hemolysis of fetal erythrocytes occurs, can be fatal to fetus, prevented if mother is treated with RhoGAM which contains antibodies against Rh antigens
  • Diagnostic blood tests
    • Complete blood count
    • Hematocrit
    • Hemoglobin
    • Prothrombin time
    • White blood cell count
    • White blood cell differential count
  • Complete blood count

    Provides information such as RBC count, hemoglobin, hematocrit, and WBC count
  • Hematocrit
    Percentage of total blood volume composed of RBC
  • Hemoglobin
    Determines amount of hemoglobin, indicates anemia
  • Prothrombin time

    Time it takes for blood to begin clotting (9 to 12 sec.)
  • White blood cell count
    Total number of white blood cells
  • White blood cell differential count
    Determines the percentage of each 5 kinds of leukocytes: neutrophils 60-70%, lymphocytes 20-25%, monocytes 3-8%, eosinophils 2-4%, basophils 0.5-1%