BLOOD 血液. Hui-pingWANG( 王会平 ),PhD DepartmentofPhysiology RoomC541,BlockC,ResearchBuilding,SchoolofMedicine Tel:

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1 BLOOD 血液 Hui-pingWANG( 王会平 ),PhD DepartmentofPhysiology RoomC541,BlockC,ResearchBuilding,SchoolofMedicine Tel:

2 Components of blood Plasma( 血浆 ) Blood Cells Red Blood Cells (RBC) or Erythrocytes( 红细胞 ) White Blood Cells (WBC) or Leucocytes( 白细胞 ) Platelets (PLT) or Thrombocytes( 血小板 )

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7 Plasmaincludes water,ions,proteins, nutrients,hormones, wastes,etc. Thehematocrit( 血细胞比容 ) isa rapidassessment ofbloodcomposition. Itisthepercentofthe bloodvolumethatis composedofrbcs (redbloodcells).

8 Hematocrit(packed cell volume, 血细胞比容 ) the volume of red blood cells as a percentage of centrifuged whole blood M: 40~50% F: 37~48% InternationalCouncilforStandardizationinHematology(ICSH) Recommendationsfor "SurrogateReference" MethodforthePackedCell the Volume

9 Physical & chemical properties of blood 1. Specific Gravity( 比重 ) Depending on hematocrit & protein composition Whole blood: 1.050~1.060 Plasma: 1.025~1.035 Red blood cells: 1.090

10 2. Viscosity( 粘度 ) relative viscosity of whole blood 4~5 depending on hematocrit relative viscosity of plasma 1.6~2.4 related to the protein composition of the plasma

11 3. Osmotic Pressure( ( 渗透压 ) Ability of a fluid to hold or attract water The osmotic pressure of a solution depends on the number of solute particles in the solution, NOT on their chemical composition and size

12 Plasma osmotic pressure (~300 mosm/l) Crystalloid Osmotic Pressure( 晶体渗透压 ) Pressure generated by all crystal substances, particularly electrolytes Important in maintaining fluid balance across cell membranes Colloid Osmotic Pressure( 胶体渗透压 ) Osmotic pressure generated by plasma proteins, particularly albumin. Approximately 25 mmhg, but important in fluid transfer across capillaries

13 isosmotic solution ( 等渗溶液 ) a solution having the same osmotic pressure as blood 0.9% saline 5% dextrose (glucose) Ringer's solution

14 4. Plasma ph Normal range: 7.35~ Buffer systems( 缓冲系统 ): NaHCO 3 /H 2 CO 3, Pro-Na/Pro, Na 2 HPO 4 /NaH 2 PO 4 Hb-K/Hb, HbO 2 -K/HbO 2, K 2 HPO 4 /KH 2 PO 4, KHCO 3 /H 2 CO 3

15 Functions of blood

16 Plasma Body Fluid = 60% of Body Weight (BW) Plasma 5% of BW Extracellular Fluid 1/3, 20% of BW 15% of BW Internal Environment Interstitial Fluid 15% f BW 70 kg Male, 42 L Intracellular Fluid Homeostasis( 稳态 ): 2/3, 40% of BW maintenance of static or constant conditions in the internal environment

17 is prepared by spinning a tube of fresh blood containing an anti-coagulant in a centrifuge the yellow liquid id component of blood

18 Composition Water (92% of plasma) serves as transport medium; carries heat Proteins (6~8% of plasma) Inorganic constituents (1% of plasma) e.g., Na +,Cl -,K +,Ca 2+ Nutrients glucose, amino acids, lipids & vitamins Waste products e.g., nitrogenous wastes like urea Dissolved gases O 2 & CO 2 Hormones

19 Plasma proteins The protein groups are separated into bands by protein electrophoresis.

20 Plasma proteins Albumins ( 白蛋白 )(60-80% of plasma proteins) most important in maintenance of osmotic balance produced by liver Globulins li ( 球蛋白 )( 1 -, 2 -, -, -) ) important for transport of materials through the blood (e.g., thyroid hormone & iron) clotting factors produced by liver except -globulins g which are immunoglobulins (antibodies) produced by lymphocytes Fibrinogen( 纤维蛋白原 ) important in clotting produced by liver

21 Red blood cells (Erythrocytes) y ( 红细胞 )

22 Structure Biconcave Nonucleus cannotperformrepair Feworganelles Without mitochondria anaerobic metabolism Small Hemoglobinmolecules

23 Count RBC count M: 4.0 0~ /L F: 3.5~ /L Hemoglobin(Hb, ( 血红蛋白 ) M: 120~160 g/l F: 110~150 g/l Hemoglobin is composed of four protein chains, two alpha chains and two beta chains, each with a ring-like heme

24 Physiological properties 1. Plastic deformability ( 可塑变形性 )

25 2. Suspension stability( 悬浮稳定性 ) Erythrocyte Sedimentation Rate (ESR) The distance that red blood cells settle in upright glass test tube of blood in one hour d Normal value [Westergren method]: M: 0~15 mm/h,f: 0~20 mm/h International Council for Standardization in Hematology (ICSH)

26 Suspension stability Erythrocyte y Sedimentation Rate (ESR) The ESR is useful in detecting inflammation in the body that may be caused by infection, some cancers, and certain autoimmune diseases such as rheumatoid arthritis and lupus. An indication of inflammation which increases in many diseases, such as tuberculosis & rheumatoid arthritis

27 Normal Sialic acid Inflammation Acute phase protein Rouleaux formation The RBCs stack together in long chains. Rouleaux formation faciliates ESR.

28 3.Osmotic fragility ( 渗透脆性 ) the susceptibility of a red blood cell to break apart when exposed to saline solutions of a lower osmotic pressure than that of the human cellular fluid

29 Notice that hemolysis begins in the 0.45% tube and is complete in the 0.35% tube. Osmotic fragility is a test to detect whether red blood cells are more likely to break down.

30 Hemolysis( 溶血 ) Redbloodcellswithout(leftandmiddle)andwith(right) g hemolysis.notethatthehemolyzed sampleistransparent, becausetherearenocellstoscatterlight.

31 Function of RBCs 1. Transport of O 2 and CO 2 2. Buffering

32 Production of RBC (Erythropoiesis)

33 Hemocytoblaststemcell Stemcellbecomescommitted Earlyerythroblastshaveribosomes y Erythroblastsaccumulateironandhemoglobin Normoblastsejectorganelles organelles Releasedaserythrocyte

34 Nutritional Requirements for Erythropoiesis 1. Many vitamins, minerals, and proteins are necessary for normal RBC production 2. Clinically, folic acid( 叶酸 ), VitB 12, and iron ( 铁 ) are the most important. Deficiencies of these factors lead to characteristic anemias( 贫血 )

35 Iron balance Most of iron for RBC production is from the metabolites of Hb of old RBCs. There is a iron balance between dietary absorption and diron loss.

36 Regulation of Erythropoiesis 1. Erythropoietin( 促红细胞生成素 ) 2. Hormones: Androgen( 雄激素 ) Others H i i d ibl Hypoxia-inducible factor-1,hif-1

37 Erythropoiesis is hormonally regulated: decreased oxygen delivery to the kidney causes the secretion of erythropoietin, which activates t receptors in bone marrow, leading to an increase in the rate of erythropoiesis.

38 Destruction of RBC Occurs in the spleen and the liver Macrophages engulf old RBCs Heme degrades into bilirubin Iron is salvaged average lifespan = about 120 days

39 Anemia( 贫血 ) Anemiaisdefinedasadecreaseintheabilityof i d d i f thebloodtocarryo 2 ) Thethreemainclassesofanemia: excessivebloodloss(acutelysuchasahemorrhageor l l h h chronicallythroughlow-volumeloss) excessiverbcdestruction(hemolysis) deficientrbcproduction(ineffectivehematopoiesis) p

40 Anemia( 贫血 ) Major causes Dietary deficiencies of iron (iron-deficiency anemia), Vit. B 12 or folic acid Bone marrow failure due to toxic drugs or cancer Blood loss from the body (hemorrhage) Inadequate secretion of EPO in the kidney disease Excessive destruction of RBCs (sickle-cell cell anemia)

41 Iron deficiency anemia( 缺铁性贫血 ):acommonanemia -ironloss(oftenfromintestinalbleedingormenses) -dietaryintakeorabsorptionofironisinsufficient. intake absorption of iron is insufficient

42 巨幼红细胞性贫血 (megaloblastic anemia) -The defect in red cell DNA synthesis -is most often due to a deficiency of vitamin B 12 and/or folic acid. -Peripheral blood smear showing hypersegmented neutrophils

43 White blood cells (Leucocytes) ( 白细胞 ) Types of WBC

44 WBC count WBC Count( 10 9 /L) % Granulocytes Neutrophils 2.0~7.050~70 Eosinophils 0.02~ ~5 Basophils 0~0.1 0~1 Monocytes 0.12~0.8 3~8 Lymphocytes 0.8~4.0 20~40 Total 4~10

45 Overview table Type Microscopic Appearance Diagram Approx. % in adults Diameter (μm) Main targets Nucleus Granules Lifetime Neutrophil 54-62% bacteria fungi multilobed fine, faintly pink 6 hours-few days (days in spleen and other tissue) Eosinophil 1-6% parasites in allergic reactions bi-lobed full of pink- orange (when stained) 8-12 days (circulate for 4-5 hours) Basophil <1% in allergic reactions bi- or tri-lobed large blue?

46 Type Microscopic Appearance Diagram Approx. % in adults Diameter (μm) Main targets Nucleus Granules Lifetime Lymphocyte 25-33% 7-8 B cells: various pathogens T cells: ocd4+ (helper): extracellular bacteria broken down into peptides presented by MHC class 2 molecule. ocd8+ cytotoxic T cells: virus-infected and tumor cells. o T cells: Natural killer cells: virus-infected and tumor cells. Monocyte 2-8% Monocytes migrate from the bloodstream to other tissues and differentiate into tissue resident macrophages or dendritic cells. Macrophage 21 Phagocytosis (human) (engulfment and 13 (rat) digestion) of cellular debris and pathogens, and stimulation of lymphocytes and other immune cells that respond to the pathogen. Dendritic cells Main function is as an antigen-presenting cell (APC) that activates T lymphocytes. deeply staining, eccentric kidney shaped NK-cells and Cytotoxic (CD8+) T- cells none weeks to years hours-days activated=days immature=mont t hs-years similar to macrophages

47 Leukopoiesis i Myeloblastsbecomeallofthegranular leukocytes Monoblastsbecomemonocytes Lymphoblastsbecomelymphocytes

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49 Physiological properties of WBC Diapedisis( i ( 血细胞渗出 ) the ability of a WBC to squeeze through the tiny gaps between adjacent endothelial cells in the vessel wall and enter tissues Chemotaxis ( 趋化性 ) Cells direct their movements according to certain chemicals in their environment. Phagocytosis ( 吞噬 ) the process of taking in particles such as bacteria

50 Functions of WBC Neutrophils, eosinophils, basophils, and monocytes contribute to the body's nonspecific defenses Lymphocytes are responsible for specific defenses

51 Platelets (Thrombocytes) Without nucleus, but can secrete a variety of substances Normal value: (100~300) x 10 9 /L Average lifespan=7~14 days Play an important role in hemostasis

52 Production ofplatelets(thrombocytes) fpl l t t Formation Formed in the bone marrow from cells called megakaryocytes Large multinucleated cells that pushes against the wall of the capillary Cytoplasmic extensions stick through and separate

53 Physiological properties of platelets 1. Adhesion Platelets adhere to the vessel wall at the site of injury vwf acts as a bridge between platelets and collagen fibrils von Willebrand factor (vwf) is a plasma protein that is secreted by endothelial cells and platelets.

54 2. Aggregation Platelets adhere to one another at the site of injury. Activation of platelets is required

55 Platelet Activation shape changed Typical smooth discoid shape of resting platelets Typical spiny spheric shape of activated platelets

56 Inducers of platelet aggregation g ADP Low dose High dose 1st reversible phase 2nd irreversible phase Thromboxane A 2 (TXA 2 ) Collagen Thrombin

57 Mechanism of aggregation Fibrinogen receptors are activated and allow platelets to become cross-linked by fibrinogen

58 Platelet Adhesion Formation of a platelet plug Platelet Activation Fibrinogen receptor Pl t l t Platelet Aggregation

59 3. Release or secretion: Plateletscontainalphaanddensegranules l t t l d l Densegranules:containingADPorATP,calcium, andserotonin α-granules:containingplateletfactor4,pdgf, fibronectin,b-thromboglobulin,vwf,fibrinogen, andcoagulationfactorsvandxiii

60 Schematic drawing of the platelet (top figure), showing its alpha and dense granules and canalicular system. The bottom figure illustrates the platelet's major functions, including secretion of stored products, as well as its attachment, via specific surface glycoproteins (GP), to denuded epithelium (bottom) and other platelets l t (left). VWF: von Willebrand factor; TSP: thrombospondin; PF4: platelet factor 4; PDGF: platelet derived growth factor; -TG: beta thromboglobulin; ADP: adenosine diphosphate; ATP: adenosine triphosphate.

61 4. Contraction Contractile proteins largely consist of myosin and actin filaments Compression and strengthening of the platelet plug Clot retraction ( 血块回缩 )

62 5.Adsorption Clottingfactors:I,V,XI,XIII

63 Function of platelets Play an important role in hemostasis

64 Hemostasis( ( 止血 ) a complex process which causes the bleeding process to stop The arrest of bleeding following injury and the result of 3 interacting, overlapping mechanisms: Vascular spasm( 血管收缩 ) Formation of a platelet plug( 血小板血栓形成 ) Blood coagulation (clotting)( 血液凝固 ) Bleeding time ( 出血时间 ):<9 min

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67 Positive feedback ( 正反馈 ) NO

68 Why does the platelet plug not continuously expand? adjacent endothelial cells are a source of signals that influence platelet aggregation g and alter blood flow and clot formation at the affected site.

69 Role of platelets l t in hemostasis Releaseofvasoconstrictingsubstances ti t Formationoftheof the "plateletplug" Promotionofbloodclotting Clotretraction

70 The process that causes blood to clot via transformation of blood from liquid into a solid gel by changing fibrinogen to an insoluble polymer (fibrin 纤维蛋白 ) To prevent excessive blood loss Disorders of coaulation can lead to an increased risk of hemorrhage or thrombosis

71 Clotting factors Clottingfactor Synonyms I fibrinogen 纤维蛋白原 II prothrombin 凝血酶原 III tissuethromboplastin 组织因子 IV Ca 2+ V proaccelerin 前加速素易变因子 VII proconvertin 前转变素稳定因子 VIII antihemophilic factor 抗血友病因子 IX plasmathromboplastin component 血浆凝血活酶 X Stuart-Prower factor XI plasmathromboplastin antecedent 血浆凝血活酶前质 XII contactfactor 接触因子 XIII fibrin-stabilizingfactor 纤维蛋白稳定因子

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73 The liver plays a critical role in producing and modifying blood-borne proteins, including those used in the clotting pathway. Moreover, bile salts from the liver facilitate the absorption of lipids in the diet, including vitamin K, which is required for the synthesis of prothrombin.

74 Coagulation process - Prothrobinase complex formation - Thrombin formation - Fibrin formation

75 Clotting pathway Intrinsic pathway (contact activation pathway) Eti Extrinsic i pathway (tissue factor pathway, more important under most circumstances)

76 Contactactivationpathway(intrinsic) Thecontactactivationpathwaybeginswithformationof activation with of theprimarycomplexoncollagenbyhigh-molecular-weight kininogen(hmwk),prekallikrein,andfxii(hagemanfactor). PrekallikreinisconvertedtokallikreinandFXIIbecomesis to and FXIIa. FXIIaconvertsFXIintoFXIa. FactorXIaactivatesFIX,whichwithitsco-factorFVIIIaform thetenasecomplex,whichactivatesfxtofxa. Theminorrolethatthecontactactivationpathwayhasin role the activation has initiatingclotformationcanbeillustratedbythefactthat patientswithseveredeficienciesoffxii,hmwk,and prekallikreindonothaveableedingdisorder. i di di d

77 Tissuefactorpathway(extrinsic) Followingdamagetothebloodvessel,endotheliumTissueFactor g (TF)isreleased,formingacomplexwithFVIIandinsodoing, activatingit(tf-fviia). TF-FVIIaactivatesFIXandFX. FVIIisitselfactivatedbythrombin,FXIa,plasmin,FXIIandFXa. TheactivationofFXabyTF-FVIIaisalmostimmediatelyinhibited bytissuefactorpathwayinhibitor(tfpi). y FXa anditsco-factorfva formtheprothrombinase complex, whichactivatesprothrombintothrombin. Thrombinthenactivatesothercomponentsofthecoagulation other components of coagulation cascade,includingfvandfviii(whichactivatesfxi,which,inturn, activatesfix),andactivatesandreleasesfviiifrombeingbound tovwf. FVIIIaistheco-factorofFIXa,andtogethertheyformthe"tenase" complex,whichactivatesfx;andsothecyclecontinues.("tenase" isacontractionof"ten"andthesuffix"-ase"usedforenzymes.)

78 3 processes 2 pathways

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80 Serum serum = plasma fibrinogen and some of the other clotting factors + substances released by vascular endothelial cells and platelets Clotting time ( 凝血时间 ):4-12 min

81 A deficiency of a clotting factor can lead to uncontrolled bleeding. Vitamin K is a cofactor needed for the synthesis of factors II, VII, IX, & X in the liver. So a deficiency of Vitamin K predisposes to bleeding.

82 Hemophilia & Bolshevik Revolution Rasputin Hemophilia: recessive, sex-linked, X chromosome genetic disease

83 Anticlotting system o Anticoagulants( 抗凝物质 ) 1. Antithrombin III (Serine Protease Inhibitor): (-) thrombin, factor IX a, X a, XI a, XII a

84 2. Protein C system synthesized in the liver as an inactive form Protein C, thrombomodulin, Protein S The activity of Protein C is markedly enhanced by its cofactor Protein S In an ninj red essel thrombin bo nd to thrombomod lin acti ates In an uninjured vessel, thrombin bound to thrombomodulin activates protein C, which blocks the clotting response.

85 3. Tissue factor pathway inhibitor (TFPI) o TFPI has three Kunitz domains which can bind to and inhibit VIIa and Xa

86 4. Heparin( 肝素 ) A polysaccharide produced by the tissue mast cells and the basophils of circulating blood Interfering primarily with the action of thrombin after combining with antithrombin III

87 Aspirin: an important inhibitor of platelet activation Phospholipid Phospholipase A 2 Arachidonic Acid Cyclooxygenase yg (COX) Aspirin 2 & PGH 2 Thromboxane synthasepgg Prostacyclin synthase (Platelets) (Vascular endothelium) TXA 2 PGI 2 Aggregation Contraction Anti-aggregation Relaxation

88 Heparin EDTA (ethylene diamine tetroacetic acid) removes Ca 2+ from plasma CPD (citrate phosphate dextrose) ties up plasma Ca 2+

89 Fibrinolysis( 纤维蛋白溶解 ) The fibrin clot is removed from the site of vascular injury during the healing process o 2 processes o Activation of plasminogen o Degradation of fibrin o 4 components of plasma a fibrinolysis s system o Plasminogen( 纤维蛋白溶解酶原 ) o Plasmin( 纤维蛋白溶解酶 ) o Plasminogen activator o Plasminogen inhibitor

90 Following tissue repair, fibrin clots are dissolved in a process mediated by plasmin; synthetic plasminogen activators can be used immediately after a stroke or heart attack to help dissolve clots and restore blood flow.

91 o 2 pathways of plasminogen activation Fibrin Degradation Products (FDP)

92 o Extrinsic Plasminogen activator Tissue-type plasminogen activator (tpa, from ECs) Urokinase (from kidney) o Plasminogen inhibitor Plasminogen activator inhibitor type-1 (PAI-1, from ECs) 2 -antiplasmin (from liver)

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94 Summary: A physiological balance

95 Blood group a classification of blood based on the presence or absence of inherited antigenic substances on the surface of red blood cells (RBCs) Erythrocytes t carry on their surfaces many antigens, but the most important and commonly recognized are the A and B substances and the Rhesus (Rh) factors ABO group Rhesus group

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98 O AB A B

99 Blood Type RBC Antigens Serum Antibodies Rh positive Rh negative Rh factor (or D ) none none none (develop Rh antibody only after exposed to Rh + blood)

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101 Blood volume & blood transfusion Blood volume The total blood volume is 7 ~ 8% of body weight. For a 70 Kg male, it is 5.0 ~ 5.5 L.

102 Blood transfusion Transfusion is the process of replacing blood or blood component which a body has lost in surgery, through h an accident or as a result of medical treatment such as chemotherapy. Sterility, Viability, Quantity, Safety & Quality

103 Basic principles 1. Unexpected, emergency blood transfusion is rarely required. It is needed only in situations of massive hemorrhage like severe trauma, gynecologic and obstetric emergency, or gastrointestinal bleeding. 2. In many cases, resuscitation can be achieved by use of colloid or crystalloid plasma expanders instead of blood. 3. Blood transfusion is not free of risk, even in the best of conditions.

104 Risk from transfusion 1. Allergic reactions to the blood or one of its components 2. Hemolytic reaction 3. Diseases transmission, i such as HIV, Hepatitis B, C virus

105 Guideline 1. Ensuring that transfusion recipients and donors have compatible blood group 2. Cross-match test 3. Tests screening for Hepatitis virus, HIV in blood donated

106 Donor Recipient Cross-match Test RBC RBC Plasma Plasma

107 Blood transfusions 输血 who can receive blood from whom?

108 Blood transfusion options Option Definition Advantage Disadvantage Preoperative Autologous Donation A patient's blood is collected and stored until needed Disease transmission and allergic reactions are eliminated Must be planned in advance May delay surgery Certain medical conditions disqualify Perioperative Blood lost during or Disease Must be planned in Autologous after surgery is transmission and Transfusion collected, processed allergic reactions are eliminated and returned advance Certain medical conditions disqualify Volunteer Blood Donation Blood voluntarily donated to a community blood center Availability in emergencies Risk of disease transmission and allergic reaction Directed Donor Blood Donation Patient selects blood donor Patient feels safe with donors selected May be higher risk of disease transmission and allergic reaction Blood type must be compatible or identical Must be planned in advance Some hospitals will not accept

109 Transfusion of whole blood Transfusion of blood components Your blood is sent to the lab to determine blood type and to check for viral diseases. It is sent to the blood component lab to be divided up into plasma, platelets and red blood cells. It goes to hospital services to be distributed to the Hospital blood bank. Finally it goes to a thankful recipient.

110 Platelets participate in hemostasis by A. aggregating to form a plug. B. releasing chemicals that promote vasoconstriction. C. secreting prostacyclin, which prevents platelet aggregation on blood vessel endothelium. D. aggregating to form a plug and releasing chemicals that promote vasoconstriction. E. All of the choices are correct.

111 Which of the following substances enzymatically causes the polymerization of plasma fibrinogen? A. Thromboplastin B. Prothrombin C. Prothrombin Activator D. Thrombin E. Phospholipids

112 Which h of the following cases would result in a fatal transfusion reaction? A. Donor group A, Host group A B. Donor group AB negative, Host group AB and Rh positive C. Donor Rh negative, host Rh positive, medical history is negative for prior transfusions D. Donor group AB, Host group 0 E. Donor group 0, Host group AB

113 Thankyouforyourattention! y