Hematology Exam Set B

Hematology Exam - Set B

• Safety Practices in Labs: Sterilizing lancets for reuse is NOT a safe practice. Proper safety measures include keeping food separate from specimens, disposing of needles in biohazard containers and frequent handwashing.

• Standard Precautions: Labs use standard precautions to prevent healthcare workers from bloodborne pathogens like HIV and HBV. These precautions apply to exposures through parenteral or non-intact mucous membranes or nonintact skin.

• Gloves: Medical examination gloves (can be sterile or nonsterile, latex or vinyl) should be used only once.

• Anticoagulants: EDTA (is commonly used in hematology and put in lavender-stoppered tubes) removes ionized calcium from whole blood via chelation. This prevents coagulation.

• Blood Smears: If a blood smear is too long, decreasing the angle of the pusher slide while smearing can correct the issue. A larger drop of blood and using a slower sliding motion don't typically help solve this.

• Erythrocyte Maturation: The correct maturational sequence for erythrocytes is: pronormoblast, basophilic normoblast, polychromatophilic normoblast, orthochromic normoblast, reticulocyte, and mature erythrocyte.

• Reticulocyte Stage: With a normal diet, an erythrocyte remains in the reticulocyte stage in the bloodstream for 2.5 days.

• Reticulocytes: Reticulocytes, when stained with Wright stain, appear blue due to polychromatophilia. This blue appearance is a component of erythrocyte maturation and development.

• Iron Transport: Transferrin is the protein that transports iron for hemoglobin synthesis.

• Embden-Meyerhof Pathway: This glycolytic pathway uses approximately 90% of the erythrocyte's total glucose.

• Oxidative Pathway: A defect in the hexose monophosphate shunt (oxidative pathway) leads to a deficiency in reduced glutathione, potential denaturation of globin, and precipitation of Heinz bodies.

• Polychromatophilia: Polychromatophilia is evidenced by a blue-colored red blood cell when stained with Wright stain. It is equivalent to reticulocytes when stained using supravital stains.

• Rouleaux Formation: Erythrocytes resembling a stack of coins on a thin blood smear section is rouleaux formation.

• Anemia Signs & Symptoms: The clinical signs and symptoms of anemia stem from diminished oxygen delivery to tissues and lowered hemoglobin concentration.

• Growth Factors for Anemia: Erythropoietin (EPO) is a growth factor produced by the kidneys used to treat anemia associated with kidney disease.

• Most Mature Normoblast: The most mature normoblast is the orthochromic normoblast.

• RBC Production Stimulation: Hypoxia, or low oxygen levels, stimulates RBC (red blood cell) production by stimulating erythropoietin (EPO) production by the kidney. This in turn increases RBC mitosis, and stem cell induction into the erythroid lineage.

• RBC Detoxification: Red blood cells (RBCs) detoxify peroxides using NADPH and reduced glutathione, products of the hexose-monophosphate shunt pathways.

• RBC Shape Maintenance: The cytoskeletal proteins, along with glycocalyx, membrane phospholipids, and GPI anchors, maintain RBC shape.

• Hemoglobin Composition: A hemoglobin molecule comprises four heme molecules and four globin chains.

• Newborn Hemoglobin: The predominant hemoglobin in a healthy newborn is fetal hemoglobin (Hb F).

• Adult Hemoglobin Distribution: Healthy adults typically have 90% Hb A, 2–3% Hb A2, and 1–2% Hb F.

• Wright's-Stained Smear Buffer: A buffer at pH 6.0 will cause red blood cells to stain too pink on a Wright's-stained smear.

• Normal Hemoglobin: Deoxyhemoglobin is considered a normal type of hemoglobin.

• Hemoglobin Dissociation Curves: Acidosis shifts the oxyhemoglobin dissociation curve to the right.

• Spleen Function: The spleen is a site for removing imperfect and aging red blood cells in normal adults.

• Blood Testing Tubes: EDTA is used for hematologic testing, and citrate is used for coagulation testing. Heparin is NOT the correct anticoagulant for coagulation testing. Using the wrong tube type is thus not acceptable for accurate blood testing.

• Parfocal Microscopes: Microscopes that remain in focus when switching between different objective lenses (like 40x to 100x) are described as parfocal.

• RBC Life Span Limitation: The loss of flexibility in cell membranes due to aging is the most responsible factor in limiting the RBC life span.

• Hematopoietic Growth Factors: The hematopoietic growth factors bind to target cell receptors, have lineage restricted activity, may promote or suppress cell death, and can stimulate or inhibit cell proliferation.

• Primary Hematopoiesis Location: The primary site of hematopoiesis in the third month of gestation is the liver.

• Erythropoietin (EPO) Information Transmission: The kidneys are the site that relays information about tissue oxygen levels to erythropoietin-producing sites.

• Hemoglobin Forms Incapable of Oxygen Transport: Carboxyhemoglobin and methemoglobin are hemoglobin forms incapable of normal oxygen transport.

• Signs of Accelerated Bone Marrow Erythropoiesis: Nucleated red blood cells in the peripheral circulation, low erythrocyte, hemoglobin, and hematocrit levels, and hypercellular bone marrow with a reduced number of red blood cell precursors can all signal accelerated bone marrow production of red blood cells.

• EDTA-Induced Problems: Platelet satellitosis can cause pseudothrombocytopenia with use of EDTA.

• Blood Smear Staining: Excessive blue staining of a blood smear is often not caused by insufficient washing, but more commonly by use of too acidic a buffer or using overly thick blood films.

• Pan-myeloid Growth Factors: Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pan-myeloid growth factor.

• Red Blood Cell Maturation Pathways: The pathways for red blood cell maturation include the Embden-Meyerhof pathway (90%), the methemoglobin reductase pathway, the Rapoport-Luebering pathway (which helps produce 2,3-DPG), and the hexose monophosphate shunt pathway.

• Hematopoiesis Locations: Primary hematopoiesis occurs in the bone marrow, with extramedullary hematopoiesis potentially occurring in the liver and spleen.

• RBC Maturation and Mitosis: Mitosis ends at the rubricyte (polychromatophilic normoblast) stage of erythrocyte development.

• Hemoglobin Production during Embryogenesis: Hemoglobins produced during early embryonic development include Gower 1, Gower 2, and fetal Hb (Hb F).

• Ratio of Anticoagulant to Blood: For coagulation studies, the recommended ratio of anticoagulant to blood is 1:9.

• Cytokines: Chemokines, interleukins, and colony-stimulating factors are all examples of cytokines.

• Platelet Satellitosis: Platelet satellitosis surrounds a polymorphonuclear leukocyte (PMN), typically seen in a citrated blood sample.

• Skin Puncture Considerations: Povidone-iodine should be avoided during skin punctures due to possible contamination. Punctures should not exceed 4mm to prevent osteomyelitis (bone infection). Infants' lateral or medial heel surfaces are preferred puncture sites.

• Packed Cell Volume (Hematocrit): The hematocrit is the volume of packed red blood cells in a given volume of whole blood.

• Erythrocyte Energy: The Embden-Meyerhof pathway provides most of the energy for erythrocytes. The hexose monophosphate shunt contributes to defense against oxidative damage.

• Predominant Hemoglobin Chains: In adults, the majority of hemoglobin is composed of 2 alpha and 2 beta chains.

• Oxyhemoglobin Dissociation Curve Shifts: A decrease in pH or an increase in CO2, or an increase in temperature shifts the oxyhemoglobin dissociation curve to the right, leading to decreased oxygen affinity.

• Normal Hemoglobin Measurement Errors: Errors in manual hemoglobin measurement like lipemia, abnormally high WBC counts, and abnormal plasma proteins can be solved by using a patient blank.

• EDTA Concentration: 1.5 mg/ml EDTA is recommended for complete anticoagulation without cell alteration. .

• Sex-Linked Enzyme Defect in Hexose Monophosphate Pathway: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common sex-linked enzyme defect in this pathway.

• Environmental Factors Affecting Erythrocyte Function: Altitude and pH affect red blood cells.

• Extramedullary Hematopoiesis: Extramedullary hematopoiesis occurs when the bone marrow cannot meet the body's demands from conditions like aplastic anemia or hemolytic anemias.

• Macrophage-Mediated Hemolysis: Macrophage-mediated hemolysis is the primary mechanism of red blood cell destruction and part of extravascular hemolysis. (accounts for 90%) .

• Cyanmethemoglobin Method Measurement: The cyanmethemoglobin method is used to measure carboxyhemoglobin, sulfhemoglobin, and methemoglobin concentrations in blood.

• Methemoglobin Reduction: If methemoglobin levels exceed 30% of total hemoglobin, intravenous methylene blue can be administered.

• Heme Synthesis Defects: Variegate porphyria, lead poisoning, and erythropoietic protoporphyria all result from defects in heme synthesis.

• Heme and Globin Synthesis Sites: Heme synthesis occurs in the normoblasts' ribosomes, while globin synthesis occurs in the mitochondria. The rubricyte is a primary site for hemoglobin synthesis.

• Hemoglobin's Oxygen Binding: One hemoglobin molecule can bind four molecules of oxygen.

• RBC Age-related Changes: As erythrocytes age, their flexibility decreases, enzyme activity (particularly glycolysis) declines, and cellular hemoglobin may not increase or decrease.

• Hemoglobin Types Comparison: Hb A1 is 2 alpha + 2 beta chains; Hb F is 2 alpha + 2 gamma chains.

• Drabkin's Reagent Composition: Drabkin's reagent consists of potassium ferricyanide, potassium cyanide, a non-ionic detergent, and dihydrogen potassium phosphate.

• Phlebotomy Errors: Improper anticoagulants, patient misidentification, and incorrect needle placement (needle at the vessel wall) are all possible phlebotomy errors.

• RBC Maturation Stages: The stages involved in red blood cell maturation include rubriblast, prorubricyte, rubricyte, and metarubricyte. The last stages capable of hemoglobin production are the rubricyte and orthochromic erythrocyte.

• RBC Maturation Trends: During RBC maturation, nuclear chromatin condenses, nucleoli disappear, and the cell diameter decreases.

• Important Stage for Polychromatophilia: Rubricytes exhibit polychromatophilia.

• Important Phlebotomy Step: Patient identification is the most critical step in phlebotomy.

• Second Trimester Hematopoiesis: The liver is the key site for blood cell production during the second trimester.

• Hemoglobin Affinity: Tense hemoglobin has lower oxygen affinity than relaxed hemoglobin.

• pH and Oxyhemoglobin Dissociation Curve: Decreased pH shifts the oxyhemoglobin dissociation curve to the right, decreasing oxygen affinity.

• Nucleoli in Cells: Nucleoli are present in immature cells.

• Number of Heme Groups: A hemoglobin molecule has four heme groups.

• Effects of Erythrocyte Aging: As red blood cells age, their cell membranes lose flexibility, enzyme activity (like glycolysis) decreases, and hemoglobin levels do not necessarily increase or decrease.

• General trends in RBC Maturation: The nuclear material compact and the overall size of the cells decreases.

Other Key Aspects (from missing context)

• Complete Blood Count (CBC): A CBC includes assessments of red blood cells, white blood cells, and platelets.

• Peripheral Blood Smear (PBS): A peripheral blood smear is a diagnostic tool that provides information about blood cells' morphology and helps identify abnormalities.

• Hemoglobin (Hb): Hemoglobin carries oxygen from the lungs to tissues and plays a crucial role in red blood cell function.

• Hemoglobin Measurements: Manual and automated methods exist for measuring hemoglobin levels with some implications when evaluating the results.

Test your knowledge on safe lab practices and standard precautions in hematology. This quiz covers essential topics such as the use of gloves, anticoagulants, and techniques for blood smears. Perfect for healthcare professionals and students alike.