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Chapter 11 - Blood! Chapter 11 - Blood! 1! Cardiovascular System! Parts:! Fluid! " Blood, a fluid CT! Pump! " " Heart! Conduits! " " Blood vessels! 2! 1! Chapter 11 - Blood! Functions of Blood - 1! 1. Transportation of:! • Dissolved gases! • Nutrients! • Hormones! • Metabolic wastes! • Heat! 2. Regulation of pH and ion composition of ECF! • Contains buffers (Chapter 2)! • Diffusion eliminates differences between blood and ECF! 3! Functions of Blood - 2! 3. "Hemostasis – blood clotting minimizes fluid loss at injuries! 4. Defense against pathogens, toxins! • White blood cells! 5. Body temperature regulation! • Redistributes heat! • Facilitates heat loss or heat gain! 4! 2! Chapter 11 - Blood! Composition of Whole Blood " " Figure 11.1! 5! Composition of Whole Blood! 1. Plasma is the fluid portion of blood! 2. Formed elements in blood! • Red blood cells (erythrocytes)! • White blood cells (leukocytes)! • Platelets (thrombocytes)! Hemo- or hematopoiesis = blood cell formation! 6! 3! Chapter 11 - Blood! Characteristics of Normal Whole Blood! 1. Temperature about 38° C! 2. Viscosity = stickiness, cohesiveness! • 5 times more viscous than water"! 3. pH: 7.35 - 7.45 (normal)! 4. Blood volume! • Adult male: 5 - 6 liters! • Adult female: 4 - 5 liters! 7! Composition of Plasma! Composition:! A. 92% water! B. 7% plasma proteins! "Albumins, globulins, fibrinogen! • Much higher [protein] (5X) than ECF! Proteins too large to leave vessels! • Osmotic pressure, clotting, immune responses, etc.! C. 1% other solutes! • Electrolytes, organic nutrients/wastes, etc.! 8! 4! Chapter 11 - Blood! Red Blood Cells - Erythrocytes! Contain hemoglobin carry O2 and CO2! 99% of formed elements are RBCs! Hematocrit = % of whole blood that is cells" • Average male: 46%! • Average female: 42%! Plasma! WBCs in “buffy layer”! RBCs! 9! RBC Structure! Biconcave discs - about 8 µm in diameter! No nucleus or most other organelles! • No nucleus → limited lifespan! • No mitochondria (why?)! About 3 million new RBCs produced per second in red bone marrow!!!! Table 11.1! 10! 5! Chapter 11 - Blood! Hemoglobin (Hb) Structure! Hb Structure:! 4 polypeptides and 4 heme groups! • Heme = iron-containing pigment! • O2 reversibly binds to iron in heme! In adults: ! • 2 α and 2 β chains (4 polypeptides, 4 hemes)! • Each Hb molecule can therefore carry 4 O2! Oxyhemoglobin abbreviation: HbO2! 11! Hemoglobin Structure " " " Figure 11.5! “-globin” means globular protein! 12! 6! Chapter 11 - Blood! Stimulus for RBC Production! Stimulus = hypoxia = low tissue O2! • Causes erythropoietin (EPO) release from kidneys! Causes of tissue hypoxia! • Anemia:! Decreased hematocrit or [Hb]! • Low blood flow to kidneys! • Decreased O2 content of air (e.g. high altitude)! • Lung damage! 13! RBC Production " "Figure 11.6! Hypoxia! 14! 7! Chapter 11 - Blood! Blood Typing! Antigen = a substance that triggers an immune response! Antibody = globular protein that binds antigen! • RBC membranes may or may not have glycolipid or glycoprotein surface antigens (agglutinogens)! • Plasma may or may not contain antibodies (agglutinins)! • Binding of antibodies to antigens causes:! ü Agglutination (clumping)! ü Hemolysis (rupture of RBCs)! " You should be able to figure this out." ABO Blood Groups " " " 15! Table 11.2! ….FYI only.......16! 8! Chapter 11 - Blood! The Bottom Line on Transfusion Reactions! ! The bottom line question to ask is:" Does the recipient’s blood have antibodies that can attack antigens on the donated blood cells? ! ! ! L! If No - Theoretically O.K. J! If Yes - “Major Bummer” 17! Transfusion Example #1! (Assume Rh factor (later) is compatible.)! Recipient (large volume) Donor (small volume) Type RBC antigens Plasma antibodies A A Anti-b B B Anti-a Will this transfusion be successful? ! • I.e. will a transfusion reaction occur? ! • Why or why not?! 18! 9! Chapter 11 - Blood! Transfusion Example 2 (Assume Rh factor (later) is compatible)! Recipient (large volume) Donor (small volume) Type RBC antigens Plasma antibodies AB AB None A A Anti-b Will this transfusion be successful?! Why or why not?! 19! Rh Factor! “Rh” comes from Rhesus monkey in which this was first studied! • Also called D antigens! • Person with Rh antigens on RBCs is Rh+" • Person without Rh antigens on RBCs is Rh-" • E.g. AB+ has A, B and Rh antigens on RBCs" Major difference from ABO grouping:! A Rh- person who has never been exposed to Rh+ blood DOES NOT have anti-Rh antibodies.! 20! 10! Chapter 11 - Blood! Importance of Rh Factor - 1! 1. Rh- person (male or female) receives Rh+ blood (proper ABO match) transfusion! • First transfusion O.K. (mild or no reaction)! • But recipient now begins making antibodies against Rh factor! • Second transfusion now a potential problem! 21! Importance of Rh Factor - 2! 2. Pregnant female:! "Rh- mother and Rh+ father → Rh+ fetus (by chance )! A. First pregnancy probably O.K., but! • During delivery, maternal and fetal blood may mix! • Mother makes anti-Rh antibodies! B. Next pregnancy with Rh+ fetus:! • Maternal antibodies may cross placenta! • Produce hemolytic disease of the newborn! " "(a.k.a. erythroblastosis fetalis)! 22! 11! Chapter 11 - Blood! Rh Factors and Pregnancy! First pregnancy with Rh+ fetus! Second pregnancy with Rh+ fetus! RhoGam:" • Anti-Rh antibodies" • Destroy fetal Rh+ " RBCs before " mother’s " Rh+ fetus! body makes " antibodies against " them" • Generally given " last trimester and" delivery" 23! White Blood Cells (WBCs or Leukocytes)! Have a nucleus, unlike RBCs! About 1% of all formed elements! • Circulate in blood for limited times! • Migrate to connective tissues of body! Granulocytes:! • Neutrophils, basophils, eosinophils! Agranulocytes:! • Monocytes, lymphocytes! 24! 12! Chapter 11 - Blood! White Blood Cells (WBCs) = Leukocytes! Table 11.1! ……….FYI only.......... 25! 1. Neutrophils! Normally the most numerous WBC! Functions:! • “First line of defense”! • Phagocytize pathogens! • Release chemicals that! "attract other WBCs! 26! 13! Chapter 11 - Blood! 2. Eosinophils! Normally rare" Functions:! • Phagocytize antigenantibody complexes! • Attack some parasitic worms! • Release antihistamine! Turns off inflammation response! (No, they don’t always look like E.T.)! 27! 3. Basophils! Normally extremely rare" Intensify inflammation:! Release histamine" • Dilates small vessels! • Increases capillary permeability! 28! 14! Chapter 11 - Blood! 4. Monocytes Become Macrophages! Normally <10% of WBCs! Functions:! • Phagocytic! • Act as antigenpresenting cells! • Call other WBCs to infection site! 29! 5. Lymphocytes! 20 - 30% of WBCs in blood! But most lymphocytes are in the tissues and lymphatic organs at any one time (i.e. not in the blood).! 30! 15! Chapter 11 - Blood! Lymphocyte Types and General Functions - 1! A. B cells attack a specific antigen! Differentiate into plasma cells which:! • • Secrete antibodies! (Label invader for destruction)! Act as antigen-presenting cells! B. T cells attack a specific antigen! • Attack virus-infected and cancerous cells, transplanted tissues! • • • Cytotoxic (Killer) T cells! Helper T cells! Suppressor T cells! 31! Lymphocyte General Functions - 2! C. Natural Killer (NK) cells perform “immune surveillance”! Function:! • Each can attack a variety of antigens" "(B and T cells are much more specific)! • Kill microbes, cancerous cells! 32! 16! Chapter 11 - Blood! Platelets (Thrombocytes)! Fragments of megakaryocytes! (i.e. are not really cells)! Very small compared to RBC! ! Function in blood clotting! 33! Hemostasis! Hemostasis = stoppage of bleeding! Three phases:! 1. Vascular phase (vascular spasm)! 2. Platelet phase (platelet plug formation)! 3. Coagulation phase (blood clotting)! ...FYI only... 34! 17! Chapter 11 - Blood! Platelet and Clotting Phases " Figure 11.9! (Factor X)" (Prothrombinase)" “Inactive blood protein” = Factor X" “Prothrombin activator” = Prothrombinase" 35! 18!