1 / 24

Ch 16: Blood

Ch 16: Blood. Plasma and Cellular Elements of Blood Hematopoiesis RBC Physiology Coagulation. Blood = connective tissue. Extracellular matrix:. Specialized cells:. Fig 16-1. Plasma. Blood Components Overview. Blood. 20-40%. Total WBC: 4,000 - 11,000. 2-8%. Cellular Elements.

lane
Télécharger la présentation

Ch 16: Blood

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ch 16: Blood Plasma and Cellular Elements of Blood Hematopoiesis RBC Physiology Coagulation

  2. Blood = connective tissue Extracellular matrix: Specialized cells: Fig 16-1

  3. Plasma Blood Components Overview Blood 20-40% Total WBC: 4,000 - 11,000 2-8% Cellular Elements 50-70% 1- 4% Fig 16-1/3

  4. Red Blood Cells O2 Fig 16-5

  5. Hem(at)opoiesis = Blood Cell Formation • Few uncommitted stem cells in red bone marrow throughout life time (Fig 16-2) • Controlled by cytokines. Examples: • Erythropoietin • CSFs and ILs: e.g. M-CSF, IL-3 (= multi CSF) • Thrombopoietin • Leukemia vs. leukocytosis vs. leukopenia

  6. Controlled by ____________,specifically CSFs and ILs Compare to Fig 16-2

  7. EPO Regulates RBC Production • “Hormone” synthesized by kidneys in response to hypoxemia • EPO gene cloned in 1985  Recombinant EPO now available (Epogen, Procrit) • Use in therapy, abuse in sport

  8. Erythropoiesis EPO release Mitotic rate  Tissue O2 RBC  bag of Hbfor carrying O2 lifespan ~ 120 days source of ATP for RBC? Maturation speed  Tissue O2 Reticulocytes enter circulation

  9. Hemoglobin (Hb) • Requires iron (Fe) + Vit. B12 (cobalamin) p.698/Ch21 • Quaternary protein structure ? • Reversible binding between Fe & O2 • CO: a toxic gas (not in book) • Bilirubin to bile. Hyperbilirubinemia • HbA vs. HbF

  10. Hb Structure Porphyrin ring with Fe in center How many O2 can 1Hb carry?

  11. RBC Disorders • Polycythemia vera (PCV ~ 60-70%) • Anemias(O2 carrying capacity too low) • Hemorrhagic anemia Fe deficiency anemia • Hemolytic anemia, due to genetic diseases (e.g. Hereditary spherocytosis) or infections • Pernicious anemia • Renal anemia

  12. Sickle Cell Anemia 1st genetic illness traced to a specific mutation: DNA:CAC CTC aa: glutamic acid valine (aa #6 of 146) HbA HbS  crystallizes under low oxygen conditions

  13. Platelets = Thrombocytes • Megakaryocytes (MKs) are polyploid. Mechanism? • MK produces ~ 4,000 platelets which live an average of 10 days. • Platelets contain gra-nules filled with clotting proteins & cytokines • Activated when blood vessel wall damaged

  14. Hemostasis = Opposite of hemorrhage  stops bleeding Too little hemostasis  too much bleeding Too much hemostasis  thrombi / emboli Three major steps: • Vasoconstriction • Platelet plug(temporary blockage of hole) • Coagulation (clot formation seals hole until tissues repaired)

  15. Steps of Hemostasis Vessel damage exposes collagen fibers Platelets adhere to collagen & release factors local vasoconstriction & platelet aggregation decreased blood flow platelet plug formation + feedback loop Fig 16-11

  16. Platelet Plug Formation Platelet activating factor (PAF)

  17. Steps of Hemostasis cont. Two coagulation pathways converge onto common pathway • Intrinsic Pathway. Collagen exposure. All necessary factors present in blood. Slower. • Extrinsic Pathway. Uses TF released by injured cells and a shortcut. • Usually both pathways are triggered by same tissue damaging events. Fig 16-12

  18. The Coagulation Cascade “Cascade” is complicated network! Numbering of coagulation factors according to time of discovery Fig 16-12

  19. Common Coagulation Pathway Intrinsic pathway Extrinsic pathway Active factor X Prothrombin  thrombin fibrinogen  fibrin reinforces platelet plug clot

  20. Structure of Blood Clot Plasmin, trapped in clot, will dissolve clot by fibrinolysis Clot formation limited to area of injury: Intact endothelial cells release anticoagulants (heparin, antithrombin III, protein C). SEM x 4625

  21. Clot Busters & Anticoagulants Dissolve inappropriate clots Enhance fibrinolysis Examples:Urokinase, Streptokinase & t-PA Prevent coagulation by blocking one or more steps in fibrin forming cascade Inhibit platelet adhesion  plug prevention Examples:

  22. Hemophilia

  23. Hemophilia A (Factor VIII Deficiency)

  24. Blood Doping the end

More Related