BLOOD

• Functions of Blood


  • Transport of gases, 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
• Compositions of Blood


  • 55% Plasma
  • 45% Formed Elements
• Plasma


  A pale yellow fluid that consists of about 91% water, 7% proteins, and 2% other components, such as ions, nutrients, gases, waste products, and regulatory substances
• Plasma Composition


  • 91% Water
  • 7% Proteins (Albumins, Globulin, Fibrinogen)
  • 2% Other solutes (Ions, Gases, Waste products, Nutrients, Regulatory substances)
• Formed Elements


  • Red Blood Cells
  • White Blood Cells
  • Platelets
• Hematopoiesis


  The continuous process that produces formed elements
• Stem Cells


  Also called hemocytoblasts, where all formed elements are derived
• Red Blood Cells


  • Disk-shaped cells that have thicker edges than the center
  • Most abundant formed cells (95% of all formed elements)
  • Lose their nuclei in order to create more space in transporting blood
  • Contains hemoglobin, the protein responsible for the red blood cells' red color
• Functions of Red Blood Cells


  1. Transports oxygen and carbon dioxide from the lungs to the various tissues in the body and vice versa

  2. Hemoglobin picks up oxygen in the lungs and releases oxygen in other tissues

  3. Carbon Dioxide is produced in tissues and transported in the blood to the lungs
• Life History of Red Blood Cells


  1. Stem cells form proerythroblasts that gives rise to a new red blood cell line

  2. Red blood cells divide. The new cells change and mature after each division

  3. The newly formed cells manufacture large amounts of hemoglobin

  4. Finally, the cells lose their nuclei and become completely mature red blood cells
• Types of White Blood Cells


  • Granulocytes (Neutrophil, Basophil, Eosinophil)
  • Agranulocytes (Lymphocyte, Monocyte)
• Neutrophil


  • Only remain 10 to 12 hours in our blood
  • Nucleus has 2 to 4 lobes connected by thin filaments
  • Cytoplasmic granules stain pink or reddish purple color and stains both acidic and basic dyes
  • Function: Phagocytizes microorganisms and other substances
• Basophil


  • Nucleus has 2 indistinct lobes
  • Cytoplasmic granules stain blue-purple color with basic dyes
  • Function: Releases histamine and heparin
• Eosinophil


  • Nucleus is often bilobed
  • Cytoplasmic granules stain orange-red or bright red in eosin (acidic dye)
  • Functions: Participates in inflammatory response of allergic reactions and asthma and attacks certain worm parasites
• Lymphocyte


  • Lymphocytic cytoplasm forms a thin ring around the nucleus
  • Functions: Produces antibodies and other chemicals responsible for destroying microorganisms, Contributes to allergic reactions, graft rejection, tumor control, and regulation of immune system
• Monocyte


  • Becomes macrophages after leaving the blood and entering the tissues
  • Functions: Phagocytizes bacteria, dead cells, cell fragments, and other debris within tissues, Break down phagocytized foreign substances and present the processed substances to lymphocytes
• Platelets


  Minute fragments of cells, each consisting of a small amount of cytoplasm surrounded by a cell membrane, Produced from megakaryocytes in the red bone marrow
• Functions of Platelets


  • Forms platelet plugs
  • Releases chemicals necessary for blood clotting
• Preventing Blood Loss


  • Vascular Spasm
  • Platelet Plug Formation
  • Blood Clotting
• Vascular Spasm


  An immediate but temporary constriction of a blood vessel that results when smooth muscle within the wall of the vessel contracts, Stimulated by chemicals released by cells of the damaged blood vessel wall and by platelets
• Formation of Platelet Plug

  1. Platelet Adhesion

  2. Platelet Release Reaction

  3. Platelet Aggression
• Blood Clotting (Coagulation)


  1. Injury to vessel, Connective tissue exposed, chemicals released

  2. Inactive clotting factors, Calcium and platelet chemicals

  3. Active clotting factors, Prothrombinase, Prothrombin, Thrombin, Fibrinogen (clot)
• Anticoagulants


  Prevent clotting factors from forming clots under normal conditions (e.g. heparin, warfarin)
• Clot Retraction


  1. Platelets form small extensions that attach to fibrin through surface receptors

  2. Contraction of the extensions pulls on the fibrin and leads to clot retraction

  3. During clot retraction, serum is squeezed out of the clot
• Fibrinolysis


  1. An inactive plasma protein called plasminogen is converted to its active form, plasmin

  2. Thrombin and tissue plasminogen activator (t-PA) released from surrounding tissues stimulate this conversion

  3. Over a few days, plasmin slowly breaks down the fibrin
• Streptokinase


  A bacterial enzyme, and t-PA, produced through genetic engineering, have been used successfully to dissolve clots
• Transfusion


  Transfer of blood or blood components from one individual to another
• Infusion


  Introduction of a fluid other than blood, such as a saline or glucose solution, into the blood
• Antigens


  Molecules on the surfaces of red blood cells
• Antibodies


  Proteins usually present in the plasma of blood
• Agglutination


  The clumping of the cells
• Hemolysis


  The rupture of the red blood cells
• ABO Blood Group


  • Type A Blood
  • Type B Blood
  • Type AB Blood
  • Type O Blood
• Transfusion reactions can occur if a person receives blood that does not match her blood type


  • Red blood cells with type A surface antigens and plasma with anti-B antibodies
  • Red blood cells with type B surface antigens and plasma with anti-A antibodies
  • Red blood cells with type AB surface antigens and plasma with neither anti-A nor anti-B antibodies
  • Red blood cells with neither antigen A nor antigen B and plasma with anti-A and anti-B antibodies
• Agglutination


  The clumping of cells
• Hemolysis


  The rupture of red blood cells
• ABO Blood Group


  • Type A
  • Type B
  • Type AB
  • Type O
• ABO Blood Group


  • Used to categorize human blood (two types of antigen: type A and type B)
• Antigens


  • Type A
  • Type B
  • Type AB
  • Type O
• Antibodies


  • Anti-A
  • Anti-B