Blood: a Fluid Connective Tissue Composed Of

Chapter 17 Blood Blood Composition • Blood: a fluid connective tissue composed of • Plasma • Formed elements • Erythrocytes • Leukocytes • Platelets Blood Composition • Hematocrit • Percent of blood volume that is RBCs • ______for males • ______for females Physical Characteristics and Volume • Sticky, opaque fluid • Color scarlet to dark red • pH • 38C • • Average volume______for males, and ______for females Functions of Blood • Distribution of • ______to body cells • Metabolic wastes to the ______for elimination • Hormones from endocrine organs to target organs Functions of Blood • Regulation of • ______by ______• Normal pH using buffers • Adequate fluid volume in the circulatory system Functions of Blood • Protection against • Blood loss • ______initiate clot formation • Infection • • Complement proteins • WBCs defend against foreign invaders Blood Plasma • • Proteins are mostly produced by the liver • • • Blood Plasma • Nitrogenous by-products of metabolism—______• Nutrients—______• Electrolytes—______

• Respiratory gases—O2 and CO2 • Hormones Formed Elements • Only ______are complete cells • ______have no ______or organelles • Platelets are ______• Most formed elements survive in the bloodstream for only a ______• Most blood cells originate in bone marrow and do not divide

Erythrocytes • Biconcave discs, anucleate, essentially no organelles • Filled with ______• Major factor contributing to blood viscosity Erythrocytes • Structural characteristics contribute to gas transport • Biconcave shape— • >______hemoglobin (not counting water)

• No ______; ATP production is anaerobic; no O2 is used in generation of ATP Hemoglobin (Hb)

• O2 loading in the ______• Produces ______(______)

• O2 unloading in the tissues • Produces ______or reduced hemoglobin (______)

• CO2 loading in the tissues

• Produces carbaminohemoglobin (carries 20% of CO2 in the blood) Hematopoiesis • Hematopoiesis (hemopoiesis): ______• Occurs in ______of axial skeleton, girdles and proximal epiphyses of humerus and femur • Hemocytoblasts (hematopoietic stem cells) • Give rise to all ______• Hormones and growth factors push the cell toward a specific pathway of blood cell development

Erythropoiesis • Erythropoiesis: ______• A hemocytoblast is transformed into a proerythroblast • Proerythroblasts develop into early erythroblasts Regulation of Erythropoiesis • Too ______leads to tissue ______• Too many RBCs increases blood viscosity • Balance between RBC production and destruction depends on • • Adequate supplies of iron, amino acids, and B vitamins Fate and Destruction of Erythrocytes • Life span: • Old RBCs become fragile, and Hb begins to degenerate • Macrophages engulf dying RBCs in the spleen

Fate and Destruction of Erythrocytes • Heme and globin are separated • Iron is salvaged for reuse • Heme is degraded to yellow the pigment ______• ______secretes bilirubin (in bile) into the ______• Degraded pigment leaves the body in ______as stercobilin • Globin is metabolized into amino acids Erythrocyte Disorders • Anemia: • A sign rather than a disease itself

• Blood O2 levels cannot support normal metabolism • Accompanied by fatigue, paleness, shortness of breath, and chills • Three causes • • • Causes of Anemia • Sickle-cell anemia • Defective gene codes for abnormal hemoglobin (HbS) • Causes RBCs to become ______Erythrocyte Disorders • Polycythemia: • Results from: • Polycythemia vera—bone marrow cancer

• Secondary polycythemia—when less O2 is available (high altitude) or when EPO production increases • Blood doping-

Leukocytes • • ______of total blood volume • Can leave capillaries via ______• Move through tissue spaces by ameboid motion and positive chemotaxis • Leukocytosis: • Normal response to bacterial or viral invasion Granulocytes • Granulocytes: • Cytoplasmic granules stain specifically with Wright’s stain • Larger and shorter-lived than RBCs • Lobed nuclei • Neutrophils • • Polymorphonuclear leukocytes (PMNs) • Give the cytoplasm a lilac color • Granules contain hydrolytic enzymes or defensins • Eosinophils • Red-staining, bilobed nuclei • • Modulators of the immune response Basophils • • Large, purplish-black (basophilic) granules contain histamine • Are functionally similar to ______Agranulocytes • Agranulocytes: • Lack visible cytoplasmic granules • Have ______nuclei Lymphocytes • Large, dark-purple, circular nuclei with a thin rim of blue cytoplasm • Mostly in lymphoid tissue; few circulate in the blood • Crucial to immunity • Two types • T cells - • B cells -

Monocytes • The ______• Abundant pale-blue cytoplasm • Dark purple-staining, U- or kidney-shaped nuclei • Become ______

Leukopoiesis • Production of ______• Stimulated by chemical messengers from bone marrow and mature WBCs • Interleukins (e.g., IL-1, IL-2) • Colony-stimulating factors (CSFs) named for the WBC type they stimulate (e.g., granulocyte-CSF = granulocytes) • All leukocytes originate from hemocytoblasts Leukocyte Disorders • Leukopenia • • Leukemias • Cancerous conditions involving ______• Named according to the abnormal ______involved • Myelocytic leukemia involves myeloblasts • Lymphocytic leukemia involves lymphocytes • Acute leukemia involves ______• Chronic leukemia is more prevalent in ______Leukemia • Bone marrow totally occupied with ______• Immature nonfunctional WBCs in the bloodstream • Death caused by ______• Treatments include irradiation, antileukemic drugs, and stem cell transplants Platelets • Not cells, but rather ______• Formation is regulated by ______• Blue-staining outer region, purple granules • Granules contain serotonin, Ca2+, enzymes, ADP, and platelet-derived growth factor (PDGF) Hemostasis • Fast series of reactions for stoppage of bleeding • • • Vascular Spasm • Vasoconstriction of damaged blood vessel • Triggers • • Chemicals released by ______•

Platelet Plug Formation • • At site of ______, platelets • Stick to exposed collagen fibers not to each other • Swell, become spiked and sticky, and release chemical messengers • ______- causes more platelets to stick and release their contents

• ______- enhance vascular spasm and more platelet aggregation Coagulation • A set of reactions in which blood is transformed from a liquid to a gel • Reinforces the platelet plug with ______• Three phases of coagulation • Prothrombin activator is formed • • Thrombin catalyzes the joining of ______

Coagulation Phase 1: Two Pathways to Prothrombin Activator • Initiated by either the intrinsic or extrinsic pathway (usually both) • • Involves a series of ______• Each pathway cascades toward ______2+ • Factor X complexes with Ca , PF3, and factor V to form prothrombin activator Coagulation Phase 2: Pathway to Thrombin • Prothrombin activator catalyzes the transformation of ______Coagulation Phase 3: Common Pathway to the Fibrin Mesh • Thrombin converts ______• Fibrin strands form the structural basis of a ______• Fibrin causes plasma to become a gel-like trap for formed elements • Thrombin (with Ca2+) activates factor XIII which: • Cross-links fibrin • Strengthens and stabilizes the clot

Clot Retraction • ______in platelets contract within ______• Platelets pull on the fibrin strands, squeezing serum from the clot Fibrinolysis • Begins within ______• Plasminogen in clot is converted to plasmin by ______, factor XII and thrombin • ______is a ______

Factors Limiting Clot Growth or Formation • Two homeostatic mechanisms prevent clots from becoming large • Swift removal and dilution of clotting factors • Inhibition of activated clotting factors • Heparin – • Warfarin (Coumadin) Factors Preventing Undesirable Clotting • Platelet adhesion is prevented by • • Antithrombic substances ______and ______secreted by endothelial cells • ______, which acts as a potent anticoagulant Disorders of Hemostasis • Thromboembolytic disorders: undesirable clot formation • Bleeding disorders: ______Thromboembolytic Conditions • Thrombus: • • Embolus: • Pulmonary emboli impair the ability of the body to obtain oxygen • Cerebral emboli can cause ______Disseminated Intravascular Coagulation (DIC) • Widespread ______blocks intact blood vessels • Severe bleeding occurs because residual blood unable to clot • Most common in Bleeding Disorders • Thrombocytopenia: • ______small purplish dots • Platelet count ______is diagnostic • Treated with transfusion of ______Bleeding Disorders • Impaired liver function • Inability to synthesize procoagulants • Causes include ______• Liver disease can also prevent the liver from producing bile, impairing fat and vitamin K absorption Bleeding Disorders • Hemophilias include several similar hereditary bleeding disorders • Hemophilia A: • Hemophilia B: • Hemophilia C: • Symptoms include prolonged bleeding, especially into joint cavities • Treated with plasma transfusions and injection of missing factors

Transfusions • Whole-blood transfusions are used when ______• Packed red cells (plasma removed) are used to ______• Transfusion of incompatible blood can be fatal Human Blood Groups • RBC membranes bear 30 types glycoprotein antigens that are • Perceived as ______if transfused blood is mismatched • Unique to each individual • Promoters of ______and are called agglutinogens • Presence or absence of each antigen is used to classify blood cells into different groups ABO Blood Groups • Types ______• Based on the presence or absence of two agglutinogens (A and B) on the surface of the RBCs • Blood may contain anti-A or anti-B antibodies (agglutinins) that act against transfused RBCs with ABO antigens not normally present • Anti-A or anti-B form in the blood at about ______

Rh Blood Groups • There are 45 different Rh agglutinogens (Rh factors) • ______are most common + • Rh indicates presence of ______Rh Blood Groups • ______are not spontaneously formed in ______– • ______form if an Rh individual receives ______blood • A second exposure to ______blood will result in a ______Transfusion Reactions • Occur if ______is infused • Donor’s cells • Are attacked by the ______• Agglutinate and ______• ______into the bloodstream • Result in • Diminished oxygen-carrying capacity • Hemoglobin in kidney tubules and ______Blood Typing • When serum containing ______agglutinins is added to blood, agglutination will occur between the agglutinin and the corresponding agglutinogens • Positive reactions indicate agglutination

Restoring Blood Volume • • Volume must be replaced immediately with • ______that mimics plasma electrolyte composition • ______(e.g., purified human serum albumin, hetastarch, and dextran) • Mimic osmotic properties of albumin • More expensive and may cause significant complications Diagnostic Blood Tests • Hematocrit – HCT, crit - (male ______; female ______) • Hemaglobin – hgb – (male ______, female ______) • RBC’s – (Male ______, female ______) • Blood glucose tests (______) • Complete metabolic panel (chem-12) • Basic metabolic panel (chem 7) • Differential WBC count (______)

Sample Lab Report Developmental Aspects • Blood diseases of aging • Chronic leukemias, anemias, clotting disorders • Usually precipitated by disorders of the heart, blood vessels, and immune system