BSC 2086 1st Edition Lecture 7 Outline of Current Lecture I. Components and Functions of BloodII. Physical Characteristics of Blood III. PlasmaIV. Blood Typing Current LectureI. Components and Functions of Blooda. Cardiovascular systemi. The heart (pump)ii. Blood vessels (conductors)iii. Blood (fluid medium)b. Blood transportationi. Oxygenii. Carbon dioxide (waste gas made once oxygen is used)iii. Nutrientsiv. Hormones v. Immune system components like white blood cellsvi. Waste products from break down of proteins and metabolism 1. Broken down in kidneys to be sent to urine or the carbon dioxide is sent to the lungs c. Functionsi. Transportation of substances ii. Regulates pH and ions (blood pH is usually 7.4)iii. Clots blood at injury sites to prevent too much blood lossiv. Defends against toxins and pathogensv. Keeps constant body temperature1. Thermoregulation through the skind. Components of Bloodi. Plasma – fluid 1. Water, dissolved plasma proteins, other dissolved substancesii. Formed elements 1. All cells and solids II. Physical Characteristics of Blooda. Three elements formed:i. Red blood cells (RBCs)1. Erythrocytes 2. Transport oxygenii. White blood cells (WBCs)1. Leukocytes2. Immune systemiii. Platelets 1. Involved in blood clotting b. Hemopoiesis: producing formed elements from myeloid and lymphoid stem cells i. Myeloid: RBCii. Lymphoid: WBCc. Fractionation: separating whole blood into plasma and formed elements in order to clinically analyze it through centrifugation.i. A thin coat is composed of platelets and white blood cells found between RBC pellet and plasmad. General Characteristicsi. Normal temperature = 38°C or 100.4°Fii. High viscosity caused by dissolved proteins and formed elementsiii. pH = 7.35 – 7.45 (slightly alkaline) iv. loss of 10% in blood volume will cause decrease in blood pressureIII. Plasma a. Compositioni. 50-60% of blood volumeii. More than 90% water iii. Exchanges with extracellular fluid across capillary walls1. Water, ions and small solutesb. Plasma Proteins i. Albumins 1. 60%2. Transport fatty acids, thyroid hormones and steroid hormonesii. Globulins 1. 35%2. Immunoglobulins antibodies3. Transport small molecules such as hormone binding proteins, metalloproteins, apolipoproteins and steroid binding proteins iii. Fibrinogen1. 4%2. Make clots3. Produce fibrin: long, insoluble strands iv. Others 1. 1%2. Change amounts of specialized plasma proteins 3. Endocrine regulation changes amount4. Peptide hormones usually found in blood:a. Insulinb. Follicle stimulating hormonec. Thyroid stimulating hormoned. Luteinizing hormonev. Origins 1. Liver: more than 90% of plasma proteins 2. Plasma cells make antibodiesa. Activated B lymphocytes 3. Endocrine hormones: make peptide hormonesc. Serumi. Liquid part of a blood sampleii. Lacks clotting proteins and calcium removed during clotting processiii. Produced when dissolved fibrinogen is converted to solid fibrin d. Red blood cells (RBCs)i. Make-Up1. 99.9% formed elements2. Make up about 1/3 of all cells in the bodyii. Hemoglobin1. Protein molecule2. Gives whole blood its color3. Transport respiratory gasesa. Oxygen from lungs to peripheral tissuesb. Binds CO2 and carries it to lungsi. Carbaminohemoglobin 4. Structure a. Quaternary structure b. 2 alpha subunit and 2 beta units = 4 globular protein subunitsi. Each has one molecule of heme c. One iron ion per heme i. Oxyhemoglobin (HbO2) associates easily with oxygenii. Deoxyhemoglobin dissociates easily from oxygen5. Fetal hemoglobina. Strong form of hemoglobin b. Found in embryosc. Greater affinity to oxygen because it is needed to transfer it from maternal circulation to fetal circulation6. Thalassemiaa. Not able to produce enough Hb subunitsb. Reduction of RBC production and fragile/short living RBCc. Affect development and growthd. If the symptoms get too severe, the person may require periodic blood transfusions or conversion of adult Hb with hydroxyurea or butyrate 7. Abundancea. Red blood cell count number of RBCs in 1 microliter of whole bloodb. Hematocrit volume of the blood sample that is occupied by the RBC compared to the entire sample of blood volume 8. Conversion and recycling a. Phagocytes break it down into componentsi. Globular proteins amino acidsii. Heme biliverdin1. Bilverdin (green) is broken down into bilirubin (yellow)2. Bilirubin sent to liver for excretion3. Jaundice: bilirubin buildupa. Yellowish skin and sclera colorb. Bile ducts blocked or liver can’t absorb or excrete bilirubin4. Some bilirubin processed into urobilinogensand sent out in urine iii. Iron is recycled1. Removed from heme, leaving only biliverdin2. Binds to transferrin and delivered to red bone marrow to make new Hb 3. Too much free iron is toxic4. Excess transferrin removed by liver and spleen and iron transferred to ferritin and hemosiderin (storage proteins) b. Hemoglobinuriai. Due to excess hemolysis in the blood, hemoglobin breaks down products in urinec. Hematuriai. Whole RBC in urine due to kidney/tissue damaged. Iron deficiency anemiai. RBC production affected by lack of iron uptake and metabolismiii. Red blood cell structure 1. Small and highly specialized discs2. Thin in middle, thicker at edgesa. Shape increases surface area to volume ratio i. Greater efficiency for movement of gases quicklyabsorbs and releases oxygen b. Rouleaux : stacks made from discs which smooth the flow through the narrow blood cellsc. Discs able to bend and flex when entering small capillaries3. Sickle cell anemia:a. Mutation of amino acid in beta chain of hemoglobinb. Mutated Hb caused by low oxygen levels alters RBC shapei. Stiffens, easily damagedii. Blocks narrow capillariesiii. Clotting, complications, deathiv. RBC lifespan1. No nuclei, mitochondria or ribosomesa. Cant repair themselves b. Use anaerobic metabolism for energy2. Live about 120 days3. 1% wear out/day4. Turnover = formation5. Macrophages of liver, bone marrow and spleen monitor RBCsa. Engulf RBCs before membrane rupture v. RBC Production1. Erythropoiesis: only occurs in myeloid tissue or red bone marrow in adultsa. Stem cells mature and become RBC b. Regulation: i. Building RBC requires 1. Amino acids2. Iron3. Vitamins B12, B6, and folic acidii. Pernicious anemia: low RBC production due to lack of vitamin B12 or lack of the intrinsic factor required to absorb B12 from the intestine 2. Erythropoietin (EPO)a. Stimulating hormone made by kidneysb. Aka.
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