PET 3322 Exam 3 Study Guide 18 03 2012 14 45 00 Chapter 19 The Blood Overview Blood Composition and Functions 1 Describe the composition and physical characteristics of whole blood Explain why it is classified as a connective tissue Only fluid tissue considered a connective tissue for two basic reasons 1 embryologically it has the same origin mesodermal as do the other connective tissue types and 2 blood connects the body systems together bringing the needed oxygen nutrients hormones and other signaling molecules and removing the wastes composed of liquid plasma and formed elements erythrocytes RBC Leukocytes WBC Platelets sticky opaque fluid with metallic tase color varies from scarlet to dark red pH 7 35 7 45 temp 38 degrees 8 of body weight avg vol 4 5L females 5 6L males 2 List eight functions of blood 1 Transportation oxygen from the lungs to cells CO2 from bodys cells to exhalation nutrients from gastrointestinal tract to body cells hormones from endocrine glands to other cells heat and waste products for elimination 2 Regulation circulation helps maintain homeostasis of all body fluids adjust body temp for absorbing and distributing heat regulate pH normal body tissues using buffer systems Adequate fluid volume in circulatory system blood osmotic pressure influences the water content of cells 3 Protection against blood loss activating plasma protein and platelets initiating clotting formation when vessel is damaged 4 Prevents Infection synthesizing and utilizing antibodies white blood cells carry on phagocytosis activating complement proteins activating WBCs to defend the body against foreign invaders Blood Plasma Discuss the composition and functions of plasma Function transports dissolved substances around body and defends against disease watery liquid extra cellular matrix that contains dissolved substances straw colored liquid plasma proteins Hepatocytes synthesize most plasma proteins o Albumins Globulins immunoglobins help attack viruses and bacteria some transport iron lipids and fat soluble vitamins Fibrinogen plays essential role in blood clotting o Antibodies or immunoglobulins produced furing certain immune responses stimulated by foreign substances o other solutes include electrolytes nutrients enzymes hormones gases and waste products Formed Elements three principal components RBC WBC and Platelets 4 Describe the structure function and production of erythrocytes Red Blood Cells o STRUCTURE Biconcave discs anucleate essentially no organelle Filed with hemoglobin Hb a protein that functions in gas transport Contain the plasma membrane protein spectrin and other proteins that give their flexibility and allow them to change shape as necessary Structural characteristics contribute to its gas transport function huge surface area to volume ratio more than 97 hemoglobin ATP generated anaerobically do not consume the oxygen they transport RBCs are dedicated to respiratory gas transport Hb reversibly binds with oxygen and most oxygen in the blood is o FUNCTION bound to Hb o PRODUCTION Hematopoiesis blood cell formation occurs in the red bone marrow of the axial skeleton and girdles epiphysis of the humerus and femur gives rise to all formed elements Development pathway consists of 3 phases 1 Ribosome synthesis in early erythroblasts 2 Hb accumulation in the late erythroblasts and normoblasts 3 Ejection of the nucleus from normoblasts and formation of reticulocytes then become mature Erythrocytes Circulating erythrocytes number remains constant reflects balance between RBC production and destruction too few hypoxia too many undesirable blood viscosity Controlled hormonally depends on supplies of iron amino acids and B vitamins Erythropoietin release by kidneys triggered by hypoxia decreased O2 and increased tissue demand for O2 Stimulus due to reduced O2 levels in blood Kidney releases erythropoietin which stimulates Red Bone Marrow which enhances and increases RBC count which increases O2 carrying ability of blood 5 Describe the chemical makeup of hemoglobin Oxyhemoglobin Hb bound to Oxygen oxygen loading takes place in lungs Deoxyhemoglobin Hb after oxygen diffuses unto tissues reduced Hb Carbaminohemoglobin Hb bound to CO2 loading takes place in tissues Hb is composed of the protein globin made up of two alpha and two beta chains each bound to a heme group o each heme group bears an atom of iron which can bind to one oxygen molecule o each Hb molecule can transport four molecules of oxygen 6 Give examples of disorders caused by abnormalities of erythrocytes Explain what goes wrong in each disorder Anemia blood has abnormally low oxygen carrying capacity symptom rather than a disease itself Blood oxygen levels cannot support normal metabolism sign symptoms include fatigue paleness shortness of breath and chills o Hemorrhagic anemia result of acute or chronic loss of blood o Hemolytic Anemia prematurely ruptured RBCs o Aplastic Anemia destruction or inhibition of Red Bone Marrow o DECREASED HEOGLOBIN CONTENT EXAMPLES Iron deficiency anemia a secondary result of hemorrhagic anemia inadequate intake of iron containing foods impaired iron absorption Pernicious anemia deficiency of Vit B12 lack of intrinsic factor needed for absorption of B12 treatment intramuscular injection of B12 application of Nascobal o ABNORMAL HEMOGLOBIN EXAMPLES Thalassemias absent or faulty globin chain in Hb RBCs are thin delicate and deficient in Hb Sickle Cell Anemia result from a defective gene coding for an abnormal Hb called hemoglobin S HbS has a single amino acid substitution in the beta chain defect causes RBCs to become sickle shaped in low oxygen situation Polycythemia excess RBCs that increase blood viscocity o Polycythemia Vera Secondaty Polycythemia Blood Doping 7 List the classes structural characteristics and functions of leukocytes Classes o Granulocytes contain cytoplasmic granules larger and usually shorter lived than RBCs have lobed nuclei ALL phagocytic cells Neutrophils take up both acidic and basic dyes give cytoplasm lilac color contain peroxidazes hydrolytic enzymes and defensins antibiotic like proteins bodies bacteria slayers Phagocytize bacteria Eosinophils kill parasitic worms destroy antigen antibody complexes inactivate some inflammatory chemicals of allergy lessen the severity of allergies by phagocytizing immune complexes Basophil U or S shaped nuclei similar to mast cells granules contain histamine anti inflammatory chemical that acts as a vasodilator and
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