Lymphocytes Blood 2

  1. Leukocytes
    • Protect against infectious microorganisms and other pathogens
    • Spend only a few hours in the bloodstream
    • Unlike RBCs, they have most organelles
    • Separated by appearance of "granules" (vesicles and lysosomes)
  2. Granular Leukocytes
    Have large visible vesicles and lysosomes after staining
  3. Agranular Leukocytes
    Have smaller ones that cannot be visualized
  4. Diapedesis of Leukocytes
    • Leukocytes can leave bloodstream by squeezing between endothelial cells of blood vessel wall
    • Allows them to enter connective tissue and organs to fight infections
  5. Chemotaxis of Leukocytes
    • Leukocytes are attracted to specific chemical signals
    • Guides them to pathogens, damaged tissue, other active WBC
  6. Phagocytosis by Leukocytes
    Leukocytes can "swallow" pathogens and cell debris
  7. Macrophage
    Monocyte that differentiates in a specific tissue for phagocytes
  8. Microphage
    Neutrophils and eosinophils are capable of phagocytosis
  9. Neutrophils
    • 2-5 lobes of nucleus
    • Barely visible granules in cytoplasm
    • Most abundant leukocyte
    • Respond to injuries first
    • Increase in number during bacterial infection
  10. Neutrophil Response to Injury
    • 1. Engulfs bacteria
    • 2. Produces and releases antimicrobial chemicals to destroy surrounding bacteria
    • 3. Produces digestive enzymes that destroy engulfed bacteria
    • 4. Secretes prostaglandins to cause inflammation and reduce spread of injury
    • 5. Secrete leukotrienes to recruit other phagocytes
  11. Eosiniphils
    • 2 lobed nucleus
    • Large granules
    • Increased numbers in parasitic infection, allergies, spleen and CNS disease
    • Phagocytosis of antigen-antibody complex and allergens
    • Release of enzymes to destroy parasites
  12. Basophils
    • S-shaped nucleus (often obscured by granules)
    • Large granules
    • Increased numbers in chicken pox, sinus infection, and diabetes
    • Secrete histamine (vasodilator)
    • Secrete heparin (anticoagulant)
  13. Lymphocytes
    • Dark, large nucleus
    • Variable amounts of cytoplasm
    • Increased numbers during any infection or immune response
    • Destroy cells (cancer, foreign, infected)
    • Present antigens to activate other immune cells
    • Coordinate immune action
    • Secrete antibodies
  14. Types of Lumphocytes
    • T Cells: attack foreign cells
    • B Cells: produces antibodies that attack antigens throughout the body
    • Natural Killer (NK) cells: detect and kill body's own cells that have been infected or are cancerous
  15. Monocytes
    • Ovoid, kidney or horseshoe shaped nucleus
    • Increased numbers in viral infections and inflammation
    • Phagocytosis of pathogens and debris
    • Attract other leukocytes
  16. Complete Blood Count (CBC)
    A count of all the cells in the blood
  17. Leukopenia
    • Disorder caused by low WBC count
    • Increased risk of infection
  18. Leukemia
    • Cancer of hemopoietic tissue producing extraordinarily high number of abnormal WBCs
    • Impaired blood clotting; lots of infections
  19. Myeloid Leukemia
    Uncontrolled granulocyte production
  20. Lymphoid Leukemia
    Uncontrolled lymphocyte and monocyte production
  21. Acute Leukemia
    Sudden onset, rapid progression, death within months
  22. Chronic Leukemia
    Undetected for months, several year survival time
  23. Platelets
    • Small fragments of megakaryocyte cells
    • Secrete vasoconstrictors to reduce blood loss
    • Stick together to form platelet plugs to seal breaks in blood vessels
    • Secrete procoagulants to promote clotting
    • Initiate clot-dissolving enzyme when clot is no longer needed
  24. Platelet Production
    • Some stem cells become megakaryoblasts
    • Megakaryoblasts replicate DNA/proteins without dividing
    • Found in bone marrow next to blood sinusoids
    • Blood flow breaks off pieces called platelets
  25. Hemostasis
    • Cessation of bleeding (otherwise hemorrhage results)
    • 3 Mechanisms: vascular spasm, platelet plug formation, blood clotting (coagulation)
    • Platelets are critical
  26. Vascular Spasm
    • Constriction of blood vessel occurring immediately after injury
    • Endothelial cells release chemicals that facilitate repair process
    • Endothelial cells become "sticky," the ones on either side of the injury stick together
  27. Platelet Plug Formation
    • Platelets stick together and to broken blood vessels
    • Platelets constrict to draw sides of broken vessel together
    • Platelets secrete chemicals that attract more platelets (positive feedback) until vessel is sealed
  28. Coagulation
    • Blood clots to form best protection against blood loss
    • Cascade of enzymes converts fibrinogen to insoluble strands of fibrin
  29. Control of Clotting
    • Anticoagulants inhibit clotting
    • Heparin (released by basophils) helps anticoagulants
    • Aspirin inhibits release of prostaglandins, which prevents platelet aggregation and clot formation
    • Ca2+ and vitamin K required for clotting
  30. Hemophilia
    • Caused by deficiency in one of the enzymes needed for clotting
    • Wounds never heal, and blooding may last days
    • Sometimes results in hemorrhage in brain that is fatal
    • Regular injections of clotting factors used as primary treatment
  31. Thrombosis
    An abnormal clotting of blood in intact blood vessel
  32. Embolus
    Piece of clot that breaks off and travels through body
  33. Medicinal Leeches
    Secrete anticoagulants as they suck blood
Card Set
Lymphocytes Blood 2
Blood 2