A P II EXAM 2 STUDY GUIDE Lesson 5 6 Blood An Introduction to Blood and the Cardiovascular System The Cardiovascular System consists of 1 A pump the heart 2 A conducting system blood vessels 3 A fluid medium blood Specialized fluid connective tissue Contains cells suspended in a fluid matrix Blood Transports materials to and from cells It contains 1 Oxygen and carbon dioxide 2 Nutrients 3 Hormones 4 Immune system components 5 Waste products Physical Characteristics of Blood Important Functions of Blood 1 Transportation of dissolved substances 2 Regulation of pH and ions 3 Restriction of fluid losses at injury sites 4 Defense against toxins and pathogens 5 Stabilization of body temperature Components of Whole Blood 1 Plasma fluid component Consists of Water Dissolved plasma proteins Other solutes 2 Formed elements All cells and solids Three Types of Formed Elements 1 Red blood cells RBCs or erythrocytes Transport oxygen 2 White blood cells WBCs or leukocytes Part of the immune system 3 Platelets Cell fragments involved in clotting Hemopoiesis Process of producing formed elements Created from myeloid and lymphoid stem cells Fractionation Process of separating whole blood for clinical analysis by centrifugation Separation into plasma and formed elements A thin buffy coat composed of platelets and white blood cells found between RBC pellet and plasma Three General Characteristics of Blood 38 C 100 4 F is normal temperature 1 2 High viscosity 5 times more viscous than water viscosity cause by dissolved proteins formed elements 3 Slightly alkaline pH 7 35 7 45 Characteristics of Blood Blood volume liters 7 of body weight kilograms Adult male 5 to 6 liters 5 3 6 4 quarts Adult female 4 to 5 liters 4 2 5 3 quarts Loss of 10 of blood volume will cause a decrease in blood pressure Plasma The Composition of Plasma Makes up 50 60 of blood volume More than 90 of plasma is water Extracellular fluids Interstitial fluid IF and plasma Materials plasma and IF exchange across capillary walls Water Ions Small solutes Plasma Proteins Albumins 60 Globulins 35 Transport substances such as fatty acids thyroid hormones and steroid hormones Antibodies also called immunoglobulins Transport globulins small molecules hormone binding proteins metalloproteins apolipoproteins lipoproteins and steroid binding proteins Molecules that form clots and produce long insoluble strands of fibrin Fibrinogen 4 Other Plasma Proteins 1 of plasma Changing quantities of specialized plasma proteins Peptide hormones normally present in circulating blood Insulin prolactin PRL and the glycoproteins thyroid stimulating hormone TSH follicle stimulating hormone FSH and luteinizing hormone LH Origins of Plasma Proteins More than 90 made in liver Antibodies made by plasma cells activated B lymphocystes Peptide hormones made by endocrine organs Serum Liquid part of a blood sample Produced when dissolved fibrinogen has converted to solid fibrin which is removed Serum lacks clotting proteins and Ca2 they used up during clotting process Red Blood Cells Red blood cells RBCs Make up 99 9 of blood s formed elements average adult has 25 trillion RBC s 1 3 of all cells in human body Hemoglobin The protein molecule that that gives whole blood its color functions to transport respiratory gases Binds and transports oxygen and carbon dioxide Normal hemoglobin adult male 14 18 g dL whole blood 1 dL 100 mL Normal hemoglobin adult female 12 16 g dL whole blood Hemoglobin Function Carries oxygen from lungs to peripheral tissues At tissues with low oxygen peripheral capillaries Hemoglobin releases oxygen Binds carbon dioxide and carries it to lungs When bound to CO2 forms carbaminohemoglobin Hemoglobin Structure Complex quaternary structure Four globular protein subunits 2 alpha subunits 2 Beta subunits Each with one molecule of heme Each heme contains one iron ion The iron ion Associate easily with oxygen oxyhemoglobin HbO2 Dissociate easily from oxygen deoxyhemoglobin Fetal Hemoglobin Strong form of hemoglobin found in embryos Takes oxygen from mother s hemoglobin Hb problem Thalassemia inability to produce enough Hb subunits Causes reduction of RBC production and fragile short lived RBC s affecting development and growth If severe may require periodic blood transfusions or treated by converting adult Hb to fetal Hb with hydroxyurea or butyrate Abundance of RBCs Red blood cell count the number of RBCs in 1 microliter of whole blood Male 4 5 6 3 million Female 4 2 5 5 million Hematocrit packed cell volume PCV percentage of RBCs in centrifuged whole blood RBC vol total vol Male 40 54 Female 37 47 Structure of RBCs Small and highly specialized discs Thin in middle and thicker at edge Three Important Effects of RBC Shape on Function 1 High surface to volume ratio Quickly absorbs and releases oxygen 2 Discs form stacks called rouleaux Smooth the flow through narrow blood vessels 3 Discs bend and flex entering small capillaries 7 8 m RBC passes through 4 m capillary Sickle Cell anemia caused by mutation of an amino acid in beta chain of hemoglobin Low O2 cause mutated Hb to alter RBC shape making it stiff easily damaged Change in shape also causes it to block narrow capillaries Can be use the same treatments as thalassemia Life Span of RBCs Lack nuclei mitochondria and ribosomes Can t repair itself and utilizes anaerobic metabolism for energy Live about 120 days RBC Formation and Turnover 1 of circulating RBCs wear out per day About 3 million RBCs per second Turnover and formation usually matched Hemoglobin Conversion and Recycling Macrophages of liver spleen and bone marrow Monitor RBCs Engulf RBCs before membranes rupture hemolyze Hemoglobin Conversion and Recycling Phagocytes break hemoglobin into components Globular proteins to break down into amino acids Heme to biliverdin organic green colored compound bad bruises look greenish because of biliverdin formation in blood filled tissues Iron recycled Breakdown of Biliverdin Biliverdin green is converted to bilirubin yellow Bilirubin transported to liver for excretion in bile Jaundice yellowish skin and sclera color is caused by bilirubin buildup Occurs if bile ducts are blocked or liver cannot absorb excrete bilirubin and circulating amounts in blood increases Bilirubin is processed further by intestinal bacteria Some processed into urobilinogens and excreted in urine Iron Recycling Iron removed from heme leaving biliverdin Binds to transport proteins transferrin and delivered to red bone marrow to
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