BSCI202 OBRIEN FINAL REVIEW SPRING 12 ALL material for final exam Blood Living cells called formed elements o Erythrocytes RBCs transport oxygen and carbon dioxide o Leukocytes WBCs fight infection o Platelets cell fragments formed from megakaryocytes important in blood clotting Nonliving plasma is the fluid and solutes Centrifuged blood o Hematocrit the RBC s that sink to the bottom compose 45 of blood o Buffy coat contains leukocytes and platelets less than 1 it is a thin whitish layer between the erythrocytes and plasma o Plasma rises to the top 55 of blood pH of blood 7 35 7 45 Blood temperature is slightly above body temperature at 38 degrees C or 100 5 degrees F Plasma 90 water o 3 major classes of plasma proteins mainly synthesized in the liver Albumins contributor to plasma oncotic osmotic pressure and act as carriers Globulins carriers clotting factors precursor proteins immunoglobulins Fibrinogen blood clotting o Nutrients glucose amino acids lipids vitamins o Wastes urea bilirubin creatine o Gases dissolved oxygen carbon dioxide o Hormones o Electrolytes relatively high concentrations of Na and Cl and low concentrations of H HCO3 K and Ca Ringer s solution distilled water containing concentrations of electrolytes etc that match the exact concentrations as their occurrence in body fluids used as IVs for dehydrated patients Acidosis blood becomes too acidic Alkalosis blood becomes too basic carbonic acid Sites of blood cell formation In each scenario the respiratory system and kidneys help restores blood pH to normal o Remember carbon dioxide can dissolve in water blood plasma and form o CO2 H2O carbonic acid H2CO3 H HCO3 bicarbonate o Fetal liver and spleen are early sites of blood cell formation o Bone marrow takes over hematopoiesis when precursor cells develop into mature blood cells by the seventh month Fetal hemoglobin differs from hemoglobin produced after birth fetal hemoglobin has a gamma remember mamma gamma subunit and higher affinity for oxygen Physiologic jaundice results in infants in which the liver cannot breakdown products fast enough 1 Erythrocytes RBC s o Main function carry oxygen o Biconcave disk large surface area favors diffusion o Essentially bags of hemoglobin o Annucleate no nucleus o Very few organelles o No mitochondria o Use anaerobic glycoloysis o 5 6 million RBCs per ml of blood o Flexible membrane o Maintain osmolarity of blood plasma pH Hemoglobin in RBCs o Binds strongly but reversibly to oxygen o 98 5 of oxygen bound to hemoglobin and 1 5 dissolved in plasma o Each hemoglobin has 4 binding sites o Can also bind to H and CO2 Imbalance of RBCs o Anemia a decrease in the oxygen carrying ability of blood o Sickle cell anemia results from abnormally shaped hemoglobin due to gene mutation of the Beta subunit of HB betty got messed up o Polycythemia an excessive or abnormal increase in the number of erythrocytes Formation of Erythrocytes o Mature RBC s are unable to divide grow or synthesize proteins o Wear out in 100 to 120 days when worn out eliminated by phagocytes in the spleen or liver o Lost cells replaced by division of hemocytoblasts in the red bone marrow o Iron is a component of hemoglobin Controlling erythrocyte production o Erythropoietin hormone that controls rate of RBC production o Kidneys produce erythropoietin as a response to reduced oxygen levels in the blood Feedback loop explained o Homeostasis is maintained by negative feedback from blood oxygen levels o Stimulus decreased RBC count decreased availability of oxygen to blood or increased tissue demands for oxygen aka exercise o All this leads to reduced oxygen levels in blood o Kidneys then release erythropoietin o Stimulates red bone more to enhance erythropoiesis more RBCs o Increased oxygen carrying capacity of blood Anemia decreased oxygen carrying ability of blood o Dietary anemia Iron iron deficiency anemia Pernicious lack of vitamin B12 o Hemorrhagic anemia bleeding 2 o Hemolytic anemia malaria or sickle cell o Aplastic anemia bone marrow defect o Renal anemia kidney disease Leukocytes WBC s o Crucial in body defense to disease o Complete cells with nucleus and organelles o Diapedesis how they move in and out of blood vessels o Move by amoeboid motion o Respond to chemicals released by damaged tissues cytokines o 4 000 11 000 WBC per cubic ml of blood 2 major types of leukocytes o Granulocytes granules in their cytoplasm can be stained possess lobed nuclei Include Granny s like more children aka 3 1 Neutrophils 2 Eosinophils 3 Basophils o Agranulocytes lack visible cytoplasmic granules nuclei are lobed spherical or kidney shaped Include 1 Lymphocytes 2 Monocytes Leukocytes most to least abundant o Never Let Monkeys Eat Bananas o Neutrophils Lymphocytes Monocytes Eosinophils Basophils Act as phagocytes at active sites of infection multilobed nucleus with Neutrophils G fine granules o Secrete cytokines in response to damaged tissues o Circulate 7 10 hours o Migrate to tissues for a few days o Increase in number during infections Eosinophils G defend against parasitic invaders parasitic worms o Large red granules contain toxic molecules that attack parasites o Phagocytes but not main mechanism of action Basophils G initiate inflammation o Non phagocytic o May defend against large parasites by releasing toxic substances o Contribute to allergic reaction histamine and heparin Lymphocyte A nucleus fills most of cell o Important role in immune response o 3 types B lymphocytes B cells 1 Effector B cells become plasma cells and secrete antibodies immunoglobins o Life span 4 7 days o Secrete 2000 antibodies specific for antigen per second o Antibodies circulate for several weeks binding marking antigen for destruction types phagocytosis complement mediated lysis osponization etc 3 2 Memory B cells allow us to fight infection a second time with a faster response Antigen anything that makes a b cell secrete antibodies then become plasma cell T lymphocytes T cells directly damage foreign cells 1 Helper T cells secret cytokines that enhance activity of B cells and other T cells enhances activity of macrophages and NK cells 2 Cytotoxic T cells secrete perforins punch holes in bad guys kills by lysis 3 Suppressor T cells regulatory cells secrete cytokines thatwhen you defeat infection these cells tell all the other immune cells to stop attacking 4 Memory T cells used for reoccurring infection T cells contact infected mutant or transplanted cells Null cells natural killers or NK
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