Ch 19 Blood Part one A The Cardiovascular System consists of 1 A pump the heart 2 A conducting system blood vessels 3 A fluid medium blood Is specialized fluid of connective tissue a b Contains cells suspended in a fluid matrix B Blood 1 Transports materials to and from cells Materials include a Oxygen and carbon dioxide b Nutrients c Hormones d e Waste products Immune system components 2 General Characteristics of Blood a 38 C 100 4 F is normal temperature b High viscosity 5 times more viscous than water c Slightly alkaline pH 7 35 7 45 d Blood volume liters 7 percent of body weight kilograms I Adult male 5 6 liters II Adult female 4 5 liters e Loss of 10 blood volume will cause a significant decrease in blood pressure 3 Functions of blood a Transportation of dissolved substances b Regulation of pH and ions c Restriction of fluid losses at injury sites d Defense against toxins and pathogens e Stabilization of body temperature C Whole Blood composed of 1 Plasma Fluid consisting of a Water b Dissolved plasma proteins c Other solutes 2 Formed elements All cells and solids a Three Types of Formed Elements Red blood cells RBCs or erythrocyte Transport oxygen White blood cells WBCs or leukocytes Part of the immune system I II III Platelets Cell fragments involved in clotting D Hemopoiesis Process of producing formed elements 1 Formed elements formed from myeloid and lymphoid stem cells E Fractionation Process of separating whole blood for clinical analysis 1 Separation into plasma and formed elements 2 A thin buffy coat composed of platelets and white blood cells found between RBC pellet and plasma fluid above F The Composition of Plasma 1 Makes up 50 60 percent of blood volume 2 More than 90 percent of plasma is water 3 Extracellular fluids Interstitial fluid IF and plasma a b Materials plasma and IF exchange across capillary walls I Water II III Small solutes Ions 4 Plasma Proteins found in blood include a Albumins 60 percent b Globulins 35 percent I Transport substances such as fatty acids thyroid hormones and steroid hormones I Antibodies also called immunoglobulins II Transport globulins small molecules hormone binding proteins metalloproteins apolipoproteins lipoproteins and steroid binding proteins I Molecules that form clots and produce long insoluble strands of fibrin soluble c Fibrinogen 4 percent protein d Other Plasma Proteins 1 percent of plasma I Changing quantities of specialized plasma proteins II Peptide hormones normally present in circulating blood i Insulin prolactin PRL and the glycoproteins thyroid stimulating hormone TSH follicle stimulating hormone FSH and luteinizing hormone LH e Origins of Plasma Proteins I More than 90 percent made in liver II Antibodies made by plasma cells activated B proteins III Peptide hormones made by endocrine organs IV Serum Liquid part of a blood sample i Produced when dissolved fibrinogen converts to solid fibrin fibrin is removed from sample ii Serum lacks clotting proteins and Ca2 used up during clotting process 2 Hematocrit packed cell volume PCV percentage of RBCs in centrifuged whole blood 2 Red blood cells RBCs A Make up 99 9 percent of blood s formed elements 1 Lack nuclei mitochondria and ribosomes 2 Means no repair and uses anaerobic metabolism to generate ATP 3 Live about 120 days B Average adult has 25 trillion RBCs 1 3 of all cells in human body C Abundance of RBCs 1 Red blood cell count the number of RBCs in 1 microliter of whole blood a Male 4 5 6 3 million b Female 4 2 5 5 million RBC volume total volume a Male 40 54 b Female 37 47 D RBC Production Erythropoiesis 1 Occurs only in myeloid tissue red bone marrow in adults a Occurs in liver and spleen from 2nd 5th month development 2 Building red blood cells requires a Amino acids b c Vitamins B12 B6 and folic acid Iron I Pernicious anemia Low RBC production i Due to unavailability of vitamin B12 or intrinsic factor produced in stomach required for vitamin B12 absorption from intestine ii Note vitamin B12 needed for normal stem cell division 3 Stem cells mature to become RBCs Hemocytoblasts a Stem cells in myeloid tissue divide to produce I II Myeloid stem cells become RBCs some WBCs Lymphoid stem cells become lymphocytes b Stages of RBC Maturation I Myeloid stem cell can produce RBC or WBC II Proerythroblast cell destined to be RBC III Erythroblasts actively synthesizes Hb After 4 days now called a noroblast IV Reticulocyte released into circulation after 2 days and continues the maturation nucleus is ejected process V Mature RBC erythrocyte 4 Erythropoietin EPO stimulating hormone a Also called erythropoiesis stimulating hormone b Secreted when oxygen in peripheral tissues is low hypoxia c Due to disease or high altitude d Functions to I Stimulate cell division in erythroblasats II Accelerate Hb synthesis Can increase RBC formation by 10 times E Structure of RBCs 1 Small and highly specialized discs 2 Thin in middle and thicker at edge F 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 G Sickle Cell anemia caused by mutation of an amino acid in beta subunit 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 use the same treatments as thalassemia H Thalassemia inability to produce enough Hb subunits Causes reduction of RBC production and fragile short lived RBCs affecting development and growth If severe may require periodic blood transfussions or treated by converting adult HB to fetal Hb with hydroxyurea or butyrate I 3 Hemoglobin The red pigment that gives whole blood its color A Binds and transports oxygen and carbon dioxide 1 Normal hemoglobin adult male 14 18 g dL whole blood note 1dL 100mL 2 Normal hemoglobin adult female 12 16 g dL whole blood B Hemoglobin structure 1 Complex quaternary structure 2 Four globular protein subunits 2 alpha subunits and 2 beta subunits a Each with one molecule of heme 3 Each heme contains one iron ion The iron ion a Associate easily with oxygen oxyhemoglobin HbO2 b Dissociate easily from oxygen deoxyhemoglobin C Hemoglobin functions 1 Carries oxygen from lungs to peripheral tissues 2 At tissues with low oxygen peripheral capillaries a Hemoglobin releases oxygen b Binds picks up carbon dioxide and
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