BSC 2086 Anatomy Physiology II Test 2 Study Guide Lecture 5 I Physical Characteristics of Blood A CHARACTERISTICS OF BLOOD Blood volume is 7 of body weight kilograms 1 Adult male 5 6 liters 2 Adult female 4 5 liters II Plasma A COMPOSTION OF PLASMA Makes up 50 60 of blood volume More than 90 of plasma is water Extracellular outside cell fluids 1 Interstitial fluid fluid that surrounds the cell 2 Plasma Materials in plasma and interstitial fluid exchange across capillary walls 1 Water ions small solutes B PLASMA PROTEINS IN BLOOD Albumins 60 used to transport substances such as fatty acids thyroid hormones and steroid hormones Globulins immunoglobulins 35 transport globulins small molecles hormone binding proteins metalloproteins apolipoproteins lipoproteins and steroid binding proteins Fibrinogen 4 soluble protein molecules that form clots and produce long insoluble strands of fibrin Other Plasma Proteins 1 of plasma 1 Changing quanitities of specialized plasma proteins 2 Peptide hormones normally present in circulating blood a Insulin prolactin PRL and the glycoproteins thyroid stimulating hormone TSH follicle stimulating hormone FSH and luteinizing hormone LH C ORIGINS OF PLASMA PROTEINS More than 90 made in the liver Antibodies made by plasma cells Peptide hormones made by endocrine organs Serum all clotting factors removed from plasma liquid part of a blood sample 1 Produced when dissolved fibrinogen converts to solid fibrin fibrin is removed from sample 2 Serum lacks clotting proteins and Ca2 used up during the clotting process III Red Blood Cells A RED BLOOD CELLS RBCs B HEMOGLOBIN Red blood cells make up 99 of blood s formed elements average adults has 25 trillion RBCs 1 3 of all cells in human body Hemoglobin the red pigment that gives whole blood its color Binds and transports oxygen and carbon dioxide Normal hemoglobin adult male 14 18 g dL whole blood Normal hemoglobin adult female 12 16 g dL whole blood C ABUNDANCE OF RBCS Red blood cell count the number of RBCs in 1 microliter of whole blood 1 Male 4 5 6 3 million 2 Female 4 2 5 5 million Hematocrit packed cell volume PCV percentage of RBCs in centrifuged whole blood RBC volume total volume 1 Male 40 54 2 Female 37 47 D STRUCTURE OF RED BLOOD CELLS Small and highly specialized discs Thin in the middle and thicker at edge E 3 EFFECTS ON SHAPE ON FUNCTION High surface to volume ratio 1 Quickly absorbs and releases oxygen Discs form stacks called rouleaux 1 Smooth the flow through narrow blood vessels Discs bend and flex entering small capillaries 1 7 8 m RBC passes through 4 m capillary 1 F DISEASES Sickle Cell Anemia caused by mutation of an amino acid in beta sub unit of hemoglobin Low oxygen cause mutated Hb to alter RBC shape making it stiff easily damaged Change in shape also causes it to block narrow capillaries 1 Can use the same treatments as thalassemia discussed later G LIFE SPAN OF RBCS Lack nuclei mitochondria and ribosomes 1 Means no repair and uses anaerobic metabolism to generate ATP 2 Live about 120 days H MORE HEMOGLOBIN Protein molecule that transports respiratory gases Structure 1 Complex quaternary structure 2 Four globular protein subunits a Each with one molecule of heme 3 Each heme contains one iron ion The iron ion a Associate easily with oxygen oxyhemoglobin HbO 2 b Dissociate easily from oxygen deoxyhemoglobin 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 carries it to lungs i When bound to CO2 hemoglobin becomes carbaminohemoglo bin Fetal Hemoglobin strong form of hemoglobin found in embryos which has a high affinity for oxygen takes oxygen from mother s hemoglobin 1 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 transfusions or treated by converting adult Hb to fetal Hb with hydroxyurea or butyrate I RBC FORMATION AND TURNOVER 1 percent of circulating RBCs wear out per About 3 million new RBCs per second Turnover and formation usually matched J HEMOGLOBIN COVERSION RECYCLING Macrophages of liver spleen and bone day marrow 1 Monitor RBCs 2 Engulf RBCs before membranes rupture hemolyze membrane bursts in cell Phagocytes break hemoglobin into components 1 Globular proteins break down to amino acids 2 Heme to biliverdin organic green colored compound bad bruises look greenish because of biliverdin formation in blood filled tissues 3 Iron recycled K BREAKDOWN OF BILIVERDIN Biliverdin green is converted to bilirubin yellow in the phagocyte 1 Bilirubin is transported by blood to liver for excretion in bile into the intestine a Jaundice yellowish skin and sclera caused by bilirubin buildup Occurs if bile ducts are blocked or liver cannot absorb excrete bilirubin circulating amounts increase to cause yellow color Bilirubin is converted by intestinal bacteria to urobilinogens and stercobilinogens L IRON RECYCLING Iron removed from heme leaving biliverdin Binds to transport proteins transferrin and delivered to red bone marrow to synthesize new Hb 2 M ISSUES WITH HEMOGLOBIN Q STIMULATING HORMONES Erythropoietin EPO 1 NOTE large quantities of free iron is toxic to cells Excess transferrin removed by liver and spleen and iron is transferred to storage proteins ferritin and hemosiderin Hemoglobinuria hemoglobin breakdown products in urine due to excess hemolysis in bloodstream Hematuria whole red blood cells in urine due to kidney or tissue damage Iron deficiency anemia lack of iron uptake metabolism affecting RBC production However excessive iron intake linked to heart disease Erythropoesis red blood cell production Occurs only in myeloid tissue red bone marrow in adults 1 Occurs in liver and spleen from 2nd 5th month of development Stem cells mature to become RBCs Hemocytoblasts stem cells in myeloid tissue divide to produce Myeloid stem cells become RBCs some N ERYTHROPOIESIS RBC PRODUCTION Lymphoid stem cells become lymphocytes O STAGES OF RBC MATURATION Myeloid stem cell can produce RBC or WBCs WBC Proerythroblast cell destined to be RBC Erythroblasts actively synthesizes Hb After 4 days now called a normoblast nucleus is ejected Reticulocyte released into circulation after 2 days and continues the maturation process Mature RBC erythrocyte P REGULATION OF ERYTHROPOEISIS Building red blood cells requires 1 Amino acids 2 Iron 3
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